zoom - Cameracraft

Sony 20-70mm f/4 G – a new type of lens

Posted on January 18, 2023 By David Kilpatrick

The 20-70mm f4 Sony G looks interesting though the UK price of £1400 is a bit over the top (under $1100 in the USA) – maybe allowing for further losses pounds vs dollar. It’s over twice the price of the Panasonic 20-60mm f/3.5-5.6 – maybe not comparable but the Lumix lens is regularly discounted by 25% or more, and partly due to being sold as a kit lens with full frame body some white box new lenses have been at 40-50% discount. It’s unlikely the Sony will be bundled as a kit lens. Even at the UK price, it looks attractive for anyone like me who might consider working with just a two-kens kit, this and the 70-300mm G. At the moment I use 17-28mm and 28-75mm f/2.8 Tamron lenses to cover the practical range this one lens almost manages, though there’s a fair gap between 17mm and 20mm.

In the specification there’s one oddity – the stated minimum focus distance and magnifications. Most wide to portrait zooms focus closer at the wide angle end. Apparently this one does the reverse, and the 0.39X close-up image scale is based on 25cm at 70mm (it’s a mystery why the specs bother to say AF and MF distances, when there’s no difference – 25cm either way!). Here’s from the spec:

**MINIMUM FOCUS DISTANCE**Wide: 0.30 m / Tele: 0.25 m (AF), 0.25 m (MF) (Wide: 0.99 ft / Tele: 0.82 ft (AF), 0.82 ft (MF))**MAXIMUM MAGNIFICATION RATIO (X)**0.39

Well, 30cm at 20mm focal length is just OK; my yardstick for min focus is that I like to see it just less than 10X focal length, so for an 85mm lens I want to get 0.85m if possible, like having anything closer and don’t like ones which only manage 1m. With a 20mm focal length 20cm close focus is desirable. The Tamron 17-28mm as an example manages 19cm at 17mm, it’s just OK, but can’t shoot any real close-ups as the largest c/u scale in 1:5.2 or 0.19X. The Sony 20-70mm manages 1:2.56, getting on for half life size, by focusing closer at 70mm than it does at 20mm.

This is such an unusual overall mix of zoom/focus behaviours that I really do want to try this lens and understand how.

The other unusual statement about the lens is that the zoom and focus design minimises breathing (desirable) and axial shift – well, I’ve not seen a zoom with axial shift, image wandering off centre when you zoom or focus, since the days of pioneering 1970s consumer glassware. Especially not a non-stabilised zoom, like this. Stabilisation has been the main reason any lens shifts off axis.

The lens weighs 488g which is great, takes 72mm filters which is not great but matches some other Sony lenses, and the size as you can see from the images here is convenient though not a single PR image sent to me shows it with a lens hood which could have some impact on bag/pocket ability. One thing’s for sure, if the dual linear motor focusing is as good as claimed, f/4 will not be a big loss over f/2.8 and carrying one lens in place of two will make this a winner for travel, landscape and urban shooting. It’s due to be in UK stores from March 3rd.

– David Kilpatrick

Lenses - E mount, News, NEX System

Sigma 16-28mm f2.8 E and L mount

Posted on June 1, 2022 By David Kilpatrick

The companion for Sigma’s highly regarded 28-70mm f/2.8 compact zoom adds an unbroken range down to 16mm while retaining a small c. 77x100mm size, 72mm filter fit, and 450g weight. It is announced today and will be available to buy from June 17th for £749.99 (UK SRP) or $899 (US retail before tax).

The new 16-28mm seen fitted to Sony’s compact A7C, with the companion 28-70mm left. The two lenses together weigh only 920g.

The full-frame Sigma 16-28mm f/2.8 DG DN Contemporary offers a promise of exceptional optical quality with a faster constant maximum aperture in barrel size similar to existing f/4 16-35mm designs. Special attention has been given to field curvature correction for edge-to-edge sharpness, important in wide-angle views – this is enabled through the use of a built-in lens profile, correcting distortion and vignetting in-camera or during raw image processing.

It uses five FLD (fluorite-like glass) elements and four aspherics to minimise chromatic and off-axis aberrations. The lens has an inner zoom mechanism that keeps overall length and the centre of balance constant, improving performance when zooming during a gimbal take. The 72mm filter thread is larger than the 67mm of the similarly light and small 28-70mm f/2.8 DG DN Contemporary.. At just 100.6mm long (L-mount version) and 450g it’s appealing for outdoor, social, street and travel photographers who want a lightweight outfit for day-long use.

The lens is constructed using aluminium and thermally stable polycarbonate, performing well in temperatures from the arctic to the equator, and has a dust and splash resistant mount. AF uses a proven stepper motor compatible with high-speed AF, DMF and AF or MF modes with an MF switch on the side. It focuses down to 25cm with a maximum image scale of 1:5.6, 0.17X and has a nine-blade rounded aperture. On the L-mount version only, linear and non-linear focus ring behaviour can be set using the USB Dock UD-11.

The lens is supplied with front and rear caps and a bayonet mounted petal lens hood. Sigma WR or WR Ceramic,WR UV and WR Circular Polarising 72mm filters are optional extras.

Sigma UK – https://sigma-imaging-uk.com

Product information – https://sigma-global.com/jp/lenses/c022_16_28_28

Lenses - E mount, News

Never say ‘zoom with your feet’…

Posted on April 16, 2017 By David Kilpatrick

There’s a dismissive and rather superior position some camera club buffs take – ‘why not zoom with your feet?’. It is well worth ignoring. The focal length of your lens, whether your use a zoom or a range of fixed focal length lenses, decides the exact relationship of elements in the picture including one component you just can’t ‘zoom with your feet’, the sky. The depth of blue above the horizon, the scale of clouds, can only be changed by using a different focal length.

Here is the cover of the May/June 2017 Cameracraft magazine, and in a very rare lapse of judgment I used one of my own photographs. I had never photographed this church before despite driving past it on the A7 Scotland to England road through the ‘debateable lands’ for the last 28 years. A quick left turn down a farm estate road led to St Andrews church of Kirkandrews, an 18th-century gem with the unusual feature of being built on a north-south alignment instead of east-west. This put the late March afternoon sun on to the south door and sundial.

Now this is a typical deliberately uncorrected 24mm steep angle shot, and I also have very straight versions taken from further away on the 24-70mm CZ f/4 lens and A7RII. but they are all at between 24 and 32mm with the church smaller and composition using the churchyard and walls. That’s because the sky simply looks best with a wide angle.

Despite some bad press, I’ve found the 24-70mm to be an excellent lens. You can get good deals and Amazon UK is showing discounts up to 19% – check our affiliate link which helps photoclubalpha cover its costs if you buy.

When we pulled up here, there was a car on the other side of the church spoiling the view I had seen from the road, spotting a dramatic old dead tree. We chatted to a lady who was looking after the churchyard and gardens, a lifelong commitment. She said it was a pity the church was locked as the interior was worth seeing – and left taking her car which had been prominently in my planned shot. So, we parked the car in the field further away, and I returned to the area of the tree.

I knew what I was looking for, and at first walked to a spot and composed this at 30mm. But by moving round and just looking at the possible camera positions (and heights above ground) I could see the relative scale of the church and tree could be changed by finding the best angle of view and perspective. This is what using your feet AND a zoom helps you do, and ‘zooming with your feet’ most certainly does not if all you have is a fixed lens. A 35mm or 28mm would have been fine here, but I knew how much clearance I wanted between the church bell tower and the branch, how large or not I wanted the fallen branches to be (and I do not ‘garden’ subjects like this which are someone else’s property).

This shot at 26mm was able to give me more sky. It’s also one which I could straighten for converging verticals (it has space to do that) using Photoshop/Camera Raw‘s excellent tools for this. To the right, there was an ugly wooden barrier to keep livestock off a sapling. Below, you can see why this was not a good addition to any composition. Earlier on there was that white car between it and the church, which had departed.

From this position, I was generally happy with the scale of the tree and church and their relative weights in a vertical composition, but felt it needed to be a little tighter.

This framing at 35mm kept all parts of the tree clear of the church, placed them neatly and avoided any strong foreground of fallen wood.

This example moved me closer to the tree, at 24mm again, giving the most attractive sky and clouds. But I felt the broken main trunk of the tree was slightly too strong and the ratio between the tree and church just missed the mark. Such small differences do count. Normally I don’t show anyone the ‘ringaround’ compositions, only the final shot. In what is essentially a landscape scene, it’s not always that important. In commercial work, including portraits, wedding or fashion you need to realise that a centimetre or two difference in where you place your lens can distinguish good photography from ordinary. This, and the timing of your shot, also marks out the best press photography.

Precision viewpoint is where both your feet and zooming come in. By moving much closer to the tree, and using it as a solid closure to the left hand side of the image, the small forked branch could be positioned to frame the church and no slightly more ugly broken branch ends would be shown. The closer viewpoint was controlled to within an inch or two side to side and vertically, by crouching slightly to get the lens in exactly the position I wanted.

This also kept the church centred and therefore without converging verticals. I was already seeing this as a black and white conversion, and possibly a cover image, with the space necessary for typical cover lines and logo. This was the picture I did use for the cover.

However, from the same viewpoint zooming to 41mm allowed a different crop with a larger scale to the church.

You can see how I have moved to my left just a small amount, and also stepped back a couple of paces to change the relationship between the forked branch and the church. This is the control you gain from a lens like the 24-70mm – and why you should zoom PLUS your feet, not zoom WITH your feet. Above all, you should walk round and look, even without the camera, studying the interplay between foreground, background, middle distance and the sky.

For my first three years of using the Sony full-frame mirrorless system I have been without a 24-70mm, using a range of primes and the 28-70mm instead. Although I had used excellent work from the 24-70mm f/4 in our magazines, from other photographers, there were so many bad reports about it. But 24mm has always been a critical focal length for me, so I had to buy it when a good deal came up (a refurb from Sony, which allows me to recover the 20% VAT which I can’t claim on regular secondhand items). Well, it’s not perfect because at 24mm the focus field is very curved (cap-shaped) to the extent that detail at the edge of the frame is focused on around 45cm when the centre is set to 45m. This can lead to the idea it’s soft. In fact, this curvature improves the sharpness of the tree trunk and the distant church at f/11 – 42 megapixels can be demanding. But if this was a portrait, with a distant scene beyond, it would have the reverse effect and make the outer field seem less sharp.

David Kilpatrick

Affiliate links to help photoclubalpha if you order the 24-70mm Carl Zeiss Vario-Tessar f/4 FE – B&H Photographic, Amazon, and WEX.

DK's ramblings, Lenses - E mount, Photo Techniques

Tamron’s super value 70-300mm USD on the A7RII

Posted on June 14, 2016 By David Kilpatrick

If you want to get a 70-300mm which works on the Sony A7RII, the A7 series body with the best on-sensor phase detection/contrast detection mix, your first choice should be the new Sony FE 70-300mm f/4-5.6 G OSS. But that demands a wallet opened with £1,150 (UK SRP) in it. In return you get a rare specification mix including focusing down to under one metre and almost a one-third life size image scale, without needing any special macro range.

For those who own either an LA-EA3 or LA-EA4 Sony adaptor, there’s a choice of A-mount lenses. The older Sony 70-300mm f/4-5.6 SSM G will work OK, but the current SSM II version is tuned for the on-sensor focusing system. Both work on the LA-EA3 with its SLT-mirror free design, and focus to a decent 1.2m. The low-cost Sony body-drive AF f/4.5-5.6 75-300mm will only AF on the LA-EA4 and is probably best ruled out.

The same goes for Tamron’s body-drive focus Di Macro, about the lowest cost such lens you can buy, and Sigma’s standard and non-APO Macro designs. For the LA-EA4 only, the Sigma 70-300mm f/4-5.6 APO Macro DG is actually worth buying as a good example can usually out-resolve any other lens of this range, but it’s slow and clunky. It focuses to under 1m and half life size scale but like the Tamron Di Macro does this using a separate close-up range you have to switch in to, only usable between 200mm and 300mm zoom setting.

This leaves two 70-300mm independent lenses with in-lens focus motors. The Sigma 70-300mm f/4-5.6 OS DG is again very good optically (a fair match for the Sony G original) but it doesn’t use an HSM focus motor. Instead it has a motor more like a Sony SAM drive. As a result, it will only focus quickly on the LA-EA4. It can’t handle on-sensor PDAF.

The Tamron SP 70-300mm f/4-5.6 Di USD can. It has an Ultrasonic Silent Drive, and this is very close in design to the Sony G SSM. Because the lens dates from 2009, most test reports have been based on DSLRs and not many Sony A7 system owners have bothered to consider it. At the current price in the UK – even the official SRP is only £275 but normally discount to a pre-VAT price of under £200, or if you like, $280 – it’s an unprecedented bargain for an advanced lens using low and extra-low dispersion elements.

You should not be surprised at its size, because it’s almost identical to the Sony G. Same weight (within 5g), same 62mm filter thread, same rear internal focus with plastic window for the scale, same forward zoom ring and single barrel extension. It has one more element, being a 17/12 design rather than 16/11 like the Sony, and it lacks the control buttons and focus range limiter controls. It’s also a quarter to a third of the price.

For me its major shortcoming is the 1.5m close focus, just too far away (nearly fell down stairs trying to get far enough away to focus when testing it, I’m just not used to lenses which force you back this way).

What counts I guess is the optical performance, and here the Tamron still does not let you down despite being a seven-year-old design. Like the Sigma OS, it is a step above any of the previous 70-300mms including Nikon’s VR and the Canon IS design and when I tested it back in 2009 it matched the Sony G SSM even wide open at 300m. What it did not do was focus accurately on my DSLR bodies, needing AF calibration adjustment on the A900 and missing the mark on the A700 and A580. It was fine on the A55.

The lens coating is pretty effective and the lens front rim, like Sony’s G, has no lettering to reflect off filters. It also has an effectively black-out inner baffle and zoom mechanism. Combined with the super-deep lens hood (very much like the monster you get with the Sony G) the result is a flare-free optic you can use in almost any light.

The rear mount is a high quality metal A-mount as expected, and on my LA-EA3 the whole assembly was firm and felt unstressed.

Tamron kindly sent me a lens to update my earlier testing when this design was new. I wanted to see one thing – did the USD drive allow PDAF on the A7RII with the LA-EA3? If it did, this bargain price but advanced lens would be a possible 300mm range solution (and also, though I can’t test this, on the A7II and A7SII – I’m pretty sure it will not play well with pure contrast detection on the A7R, as on my A7 it will focus at all focal lengths and in low light but can take several seconds of hunting and fine tuning in small steps).

Fitted to the A7RII+LA-EA3 I found it snaps into focus really fast, able to use either wide area or centre AF with much the same speed as native E-mount lenses, and activating the ‘green square’ focus point display. It was very poor using moveable Spot AF (unusable in low light), and the Zone AF option is greyed out. So, it can’t access all areas, but for regular shooting it’s good.

At focal lengths over 150mm, it can be spooked by starting completely out of focus. However, once the lens is not extremely defocused it acquires and tracks rapidly. The full time manual focus over-ride can help set it up before you use AF. In very low light with low contrast targets, at 200-300mm, even prefocusing manually may not prevent a long searching process or AF failure. However, in normal daylight with regular 3D subject matter it’s useable.

Since owners report that even Sony’s own lenses encounter similar issues – the 90mm f/2.8 G OSS Macro is known for hunting and taking time to lock on – it’s an issue more to do with the way the on-sensor focus works than anything else. It’s also much better than, for example, the Canon 70-300mm f/4-5.6 L used on the Sigma MC-11 or Commlite adaptors. That just gives up towards 300mm.

The Tamron has variable bokeh qualities. Foreground bokeh can be untidy and contours just beyond the plane of focus can be harsh. Totally defocused detail in both foreground and background can look very smooth. It has a nine-blade circular aperture, just like the Sony G A-mount, and I’d say overall image look was uncannily similar. The exact look depends on the focal length, working distance, aperture and placing of the foreground and background detail.

Purple rhody at f/6.3 and 300mm – not too bad overall!

Matching person in the distance – again, not bad, with a pleasant three-dimensional look. Maybe I should do a version in black and white…

As for this lens not having VC (Tamron’s OS/OSS) I can only say it doesn’t need it when Sony’s 5-axis sensor stabilisation does so well. Here you can see 1/30s wide open at 300mm indoors at ISO 3200. Note also what CA or fringe occurs. It’s pretty good.

As for handling 42 megapixels, which didn’t exist when the Tamron was designed, there doesn’t seem to be a serious problem. Here’s a quick shot of Scotland’s relationship with the USA and Europe…

And here, frozen by 1/500s shutter speed at the realistic aperture of f/7.1 and ISO of 200, is a detail at 100% size. I’m generally happy with a 70-300mm lens if you can see the weave and the stitching on our town hall flags at 300m, 2/3rds of a stop down from full aperture, reproduced on a 1.5m wide print.

I’ll test the lens further and add a gallery of images and any other comments, but I think that this is the only non-Sony lens of this range which really works well with the LA-EA3 (and of course, extremely well too with the LA-EA4 given AF calibration).

The only slight incompatibility is that the camera/adaptor gives the lens the identity of the Sony 70-300mm f/4-5.6 G SSM, this is what appears in the EXIF. This also means that the camera will invoke an auto profile for the Sony lens, and handle the focusing as if this was the Sony lens. It also loads the built-in profile for the SSM G lens in Lightroom/Adobe Camera Raw. This seems to work just fine. Without the profile enabled, the flag shot for example shows a stop or more of vignetting which is a relative weakness of the design – exactly as it is with the Sony. The new FE G lens with its 72mm front element as opposed to the 62mm of the Sony G, Sigma OS and Tamron SP designs can be expected to have much less full aperture vignetting.

Please note that this report refers specifically to the A7RII as a host body – as stated, it’s not useful on the A7 and I also found it’s not good enough to use on the A6000 with LA-EA3 (fine with LA-EA2 or LA-EA4). It will eventually focus but with too much hunting and missing.

– David Kilpatrick

If you’d like to check availability or order the lens, here are my affiliate links (may help pay for the site, don’t cost you anything):

Wex Photographic, UK – £239

B&H, USA & World – $449 ($100 rebate to June 30th)

Amazon UK – £239 at time of publication

Accessories - 3rd party, Equipment Reviews, Lenses - Alpha Mount, Sony Digital Cameras

Sony 28-75mm f/2.8 SAM on mirrorless FF

Posted on April 15, 2016 By David Kilpatrick

With the 24-70mm f/2.8 new Sony GM FE lens selling for £1799 (UK) and the A-mount version two 24-70mm f/2.8 for a full £100 more, the cost of a basic mid-range zoom to use with a camera like the A7RII remains very high. There are good arguments to be happy with the 24-70mm f/4 FE zoom, or even the 28-70mm f/3.5-5.6 though that is best limited to use on the A7 (24 megapixel) and A7S (12 megapixel) bodies rather than the A7R (36 megapixel) or A7RII (42 megapixel).

Of course there are good lens adaptors out there and 24-70mm f/2.8 lenses from Canon, Tamron or Sigma with ultrasonic focus drive in Canon EF mount offer one solution. The original 24-70mm f/2.8 for A-mount with its SSM motor of this type can also be found for a fair price. But there’s one lens which I sold after my A7R arrived, mostly because I was parting company with my full-frame A-mount body survivors. It’s the Tamron-based but Sony revised SAL 28-75mm f/2.8 SAM.

Although I did have an LA-EA3 adaptor to use SSM and SAM drive A-mount lenses on the E-mount bodies, the 28-75mm didn’t really work very well on the A7R so it remained on my A99 or A900. I made a few tests and saw that it was certainly OK on 36 megapixels, though even on the 24 megapixel A99 where it played nicely with the AF system it had slightly soft corners when used wide open. They were not any softer than the 24-70mm f/2.8 Carl Zeiss of that time and in some ways the lens was better behaved.

The first thing to do was to fix this lens to the LA-EA3 creating an FE lens unit. Imagine the adaptor is just part of the lens (that’s pretty much how Sony makes many lenses for E-mount anyway). The total unit measures up at 115mm long including the adaptor, and 75mm diameter taking 67mm filters. The lens itself weighs only 565g, the combo weighs 683g with adaptor and lens hood. That compares with the new GM lens at 136mm long and 88mm diameter using 82mm filters and weighing 886g. As I already have a 16-35mm f/4 CZ which covers the 24mm requirement well, the 28-75mm range is just as useful to me as 24-70mm.

While the 28-75mm SAM activates PDAF and multiple AF points, it’s not the full works with tracking and Eye-AF. But it’s also not as noisy as some reviews imply. It’s much quieter than the 85mm f/2.8 SAM, and silent compared to the grinding focus of the 30mm DT SAM macro. Startup is fast, with the lens initialising quicker than FE mount stabilised zooms. The aperture actuation is slicker than with body-drive SAL lenses on the LA-EA4, and quieter. Focus is fast and the only downside is the rotating focus ring which does not support DMF or over-ride on the fly, or auto manual focus magnification. Manual focus requires you to set it on the lens and the body, and whatever you are doing, you need to avoid either turning the focus ring when there is any resistance, or blocking it from turning during AF. It’s a bit vulnerable and the direction of focus is the opposite to normal Sony/Minolta design. The zoom ring which locks at 28mm only operates in the normal direction.

So, what you get with the LA-EA3+28-75mm SAM is basic but fully controlled and communicating, EXIF accurate with profile correctly invoked. It will track with continuous focus and during movies, though slightly noisy for in-camera sound recording; it seems to do so when some SSM lenses, like the 24mm f/2 CZ, don’t play.

As for optical quality, it’s still a 14-year-old Tamron in disguise, but it can match up to 42 megapixels centrally across its full range. The performance over the APS-C image area is superb, even wide open at all focal lengths, with just a hint of misty aberrations slightly masking a super-sharp result on axis. On full frame, a marked ‘cap shape’ deviation from flat field towards the extremes causes strong softening on flat subjects and landscapes at 28mm and is not entirely removed at longer lengths. You would not want to use this at 50mm and f/2.8 if you had a faster 50mm you could fit and stop down to f/2.8. On real three-dimensional subjects at typical working apertures between f/4 and f/11 it can be extremely sharp. The respectable 38cm close focus and 0.22X subject scale (not as good as the new Sony GM 24-70mm) reveal microscopic detail on the A7RII at f/5.6. The shot below is at the closest AF on the large water drop in the centre, at 75mm and f/5.6 – you can see the bokeh is very acceptable, not complex or ‘nervous’ which it tends to be when used wide open for more distant subjects with a slightly defocused background.

A 100% crop from th A7RII file (converted from raw ISO 500 14-bit, without any sharpening for web and with minimal NR) gives an idea how good this lens is and also just how little depth of field you’re ever going to see from a 42 megapixel full frame image used this way!

It would hardly be worth buying an LA-EA3 and a new 28-75mm just to save about £1000 over the GM 24-70mm. If you already own an LA-EA3 and you can find a cut price or good used 28-75mm go for it. The way its aperture works means you’ll get very fast low light focus and minimal shutter lag (but you do need a mark II A7 series body to get the best functioning).

The zoom action is a real pleasure to use, very light but positive, and the overall build and feel of the lens will not disappoint. It also seems to get just the right response from the in-body stabilisation of the A7RII. Sure, 67mm filters may be smaller than many midrange zooms require, but I will either have to use a stepping ring or get a couple of new filters – not cheap, for the quality needed to maintain the lens performance. Also, it’s not weatherproofed.

Here’s a quick set of three hand held (with SSI) comparisons at 28mm – f/2.8, f/5.6 and f/9. I’ve loaded these up at full size so they should open the original Level 10 sRGB JPEG when clicked. The focus in on the foreground railing spike and the fine spider web gives the best idea of how the resolution and contrast of the lens improve from wide open. It’s clearly resolved at f/2.8 but with a gentle ‘glow’ at pixel level. First image – f/2.8.

Second image – f/5.6. If you download all three images and load them into Photoshop, it’s interesting to switch between tabs and see the depth of field change.

The third image is at f/9 and here the ISO is high at 2000. The A7RII can produce great results up to 3200 but I might not choose to have this at 2000. Even so, the sharpness can be judged without problems as the noise doesn’t have much effect on fine detail with current Sony sensors and processing. It always shows more in defocused, smooth areas.

Because I use other lenses – such as the 24-105mm f/3.5-4.5 Sony and 50mm f/2.8 Macro Sony on LA-EA4, 40mm f/2.8 Canon STM, Sony FE 28mm f/2, 16-35mm CZ f/4 and also the unrivalled 24-240mm FE zoom I have many choices overlapping the range of this lens. I remember that for landscape work on the A900 it was hard to beat. Here’s one of my images from that combination, using a 6 second exposure at 40mm focal length, f/8 and ISO 100 with a variable ND filter. With the restrictions on tripod position given by the location, the zoom range of 28-75mm proved just right for a range of studies.

With this lens arriving during a period (for my corner of the UK) of sustained white skies and drizzling rain, it’s not been out and about much. One thing it has done is to focus very well in dim room lighting on my sofa companions –

And, for those who don’t think f/4 is wide enough and desperately want 55mm f/1.8 or f/0.95 lenses, this is at 55mm f/2.8 and of course when the iris of the eye is sharp the fur around it is not and Willow’s nose is blurred. Once again, despite correction for tungsten light at the extreme limit of Adobe Camera Raw, and using ISO 3200, it’s pretty amazing what the A7RII can do seen at 100% (below).

But this super-shallow depth of field is what happens at 42 megapixels. Depth of field used to be worked out based on a 10 x 8″ print held in your hand, not a 6 x 4ft image viewed through the ‘window’ of a screen. Of course for social media you do indeed need very wide apertures because when your pictures are mostly viewed on smartphones, it’s like looking at a contact print from a Vest Pocket Kodak…

To support Photoclubalpha, subscribe to f2 Cameracraft (it’s probably the only photo mag edited by two long-standing Sony system users, myself and Gary Friedman).

– David Kilpatrick

You can find deals for the Sony SAL 28-75mm f/2.8 SAM A-mount lens at B&H Photographic, Wex Photographic for the UK, or Amazon Sony SAL2875 Alpha 28-75mm F2.8 Standard Zoom Lens

DK's ramblings, Equipment Reviews, Lenses - Alpha Mount, NEX System

No FE or A mount for new Sigma 24-35mm f/2

Posted on June 18, 2015 By David Kilpatrick

We’ve had news of the new Sigma Art HSM high speed wide angle full frame zoom – 24-35mm f/2.

It will be available in Nikon, Canon and Sigma mounts only (release date not yet confirmed) according to Sigma in the UK.

Note that this will be a bit of monster with its 82mm filter thread, 117mm long barrel and substantial petal lens hood.

Sigma does not make a full frame DSLR. Sony is now a major market for high end full frame lenses. What’s going on here? We’ll just have to wait and see. Maybe Sigma just reckon every FF Sony mirrorless owner will have a Canon AF adaptor and maybe their HSM – which works pretty well on the A7II – will even allow fast AF on the new A7R II.

– David

Accessories - 3rd party, Lenses - Alpha Mount, Lenses - E mount, News

Using the 10-18mm OSS zoom on full frame

Posted on December 3, 2013 By David Kilpatrick

The Sony E-mount (not FE) 10-18mm f/5 OSS lens can be used effectively on full frame for creative work and within limits for technically more demanding shots. Below, an uncropped A7R shot of the concourse at Abu Dhabi Airport, taken at 13mm setting, f/6.3 with my lens profile as provided below. Check the straight lines in the floor tiling, if you doubt that this lens would be of any use for architecture.

However, you don’t get this without a lens profile, and without due care to limit the focal length to a range of 13 to 16mm – not the full 10 to 18mm. Below, you could get this if you try 12mm straight out of camera…

This is a pretty awful case of vignetting and distortion – as you would expect. It’s from an APS-C format wide angle zoom, the 10-18mm f/4 SEL OSS lens for NEX, used on the Alpha 7R full frame mirrorless body. Early in the launch period of this camera, various far more attractive images appeared on-line using subjects like roads, rail lines, beaches and even shop counters where the lines look straight – rather like that drainpipe – because of where they fall in the shot. As you can see, anything with a horizon near the long edge of the framewould have given a very different impression.

However, Adobe offers a free utility which enables you to make lens profiles to correct vignetting and distortion.

I created a lens profile for ACR/LR using full frame and the 10-18mm on the A7R. The vignetting is such that the profile creator really can’t handle it, and overcorrects the extreme corners as a result. I’ve done f/4, f/8, f/16 at 12, 14, 16 and 18mm focal lengths using an A2 chart; for a lens like this, a much greater working distance and an A0 chart would really be desirable. The link below is to a zip file of the Adobe Lens Profiles I produced – for A7 and A7R, with .lcpp files for final use, and .lcp files for different settings of the 10 18mm I found useful.

10-18AdobeLensProfiles

At 12mm you can probably see the vignetting artefacts in the corners, the magenta corner shift and incomplete correction of the horizon line. You’ll also be quick to spot that the 12mm coverage has been reduced to something much less, lens profiles always reduce the field of view (they can not do otherwise).

The profiler simply can’t handle the degree of sudden fall-off in illumination given by the 10-18mm used on full frame. Manual distortion corrections can actually do a better job. At other focal lengths, the profile I’ve made works well enough, and if the frame is cropped slightly (still exceeding the APS-C area the lens is designed for) it’s possible to get good results and wider angles.

I have sold my Sigma 12-24mm HSM II which was used with the A99, and also sold a Voigltander 15mm f/4.5 I bought to test (zero cost fortunately, as it made a small profit between Gumtree source and eBay destination). The Sigma was not only very difficult to focus using CD, its HSM motor won’t play with Sony CD.

My .lcp full-frame file can be downloaded from:

//www.photoclubalpha.com/AdobeCameraProfiles/ILCE-7R FF (E 10-18mm F4 OSS) – RAW.lcp.zip

Just for good measure, here is an uncropped A7R 13mm focal length shot of the church of Maila Dumpara in Kerala taken to use dramatic converging verticals – which fail terribly unless the lines are properly corrected, the last thing you want in a strong upward angle is lens distortion. It’s very stiff test of any lens to do this. I have left the vignetting uncorrected. I rather like it. Click either this or the Abu Dhabi photo and you’ll get a larger image, about 1000 x 1500 pixels.

Samples produced for a dPreview forum question

There’s been a lot of discussion on dPreview forums of which lenses work on full frame E-mount, as Sony saw fit to put a Disable APS-C crop option in the menus of the A7 and A7R (almost as if they wanted owners to experiment). They have made other welcome changes of a similar kind which I’ll cover in a full review of the camera – which I can not do yet as I have no FE mount lenses for it, and with the current choice and prices, I can see I may never use FE mount lenses on this camera.

So, to answer some questions on dPreview’s E-mount forum, I posted these images and comments.

Here is a ‘native’ uncorrected shot of a local building taken on the 10-14mm on A7R at 11mm, f/10, ISO 100:

View: original size

Here is the result of using the profile, doing a crop and some straighten of slight rotated tilt, and pulling the scale down (with the profile applied, the roof apex is clipped off at the top as the lens has so much distortion its 11mm probably becomes more like 15mm when corrected):

View: original size

I’ve used some clarity and local burn adjustments on the sky to treat the image more or less as I would (except that I wouldn’t actually photograph this building at this time of day, with blinds drawn, etc).

For me, the 10-18mm on A7R with our without the profile correction offers the same options as using assorted lenses on 5 x 4 sheet film. It never mattered whether a 47mm didn’t cover the entire film, you got an image circle and could use whatever part of it you want. At 10mm the image, with the profile used, has strong corner cut-off but the overall circle of usable image greatly exceeds APS-C provided you stop down (f7.1 seems just OK, f/10 is maybe optimum, I’d certainly try f/16 despite fears of detail loss).

View: original size

The red crop mark is square – my ‘Hasselblad SWC killer’, as the classic SWC had just a 38mm wide angle lens. You needed to get an Arcbody with 35mm Rodenstock to go any wider on 56 x 56mm film (6 x 6). With the A7R and 10-18mm at 10mm, you get the equivalent of a 24mm lens. Not a 24mm fisheye on 6 x 4.5 like the widest ever offered by Mamiya… a 24mm rectilinear on 6 x 6.

The yellow crop mark represents a significantly larger area than APS-C (which is actually just a little under the 24 x 24mm square in width). It is shifted vertically, as if the lens was being used as a shift lens. If only the APS-C area is considered, its approximately 16 x 24mm area can be positioned right to the top of the frame, equalling a 4mm rise, or the equivalent of using a 6mm rise on a full-frame PC lens (most actually go to 11 or 12mm rise). There is only one lens made which can compete with this, and that’s the Canon 17mm f/4 TS. Admittedly this is a superb lens and when stopped down to f/11 and used on the 6D (Canon’s most shift-friendly sensor) will blow this result away for clean rendering of detail toward the frame edges.

And then, you can still use the 10-18mm in APS-C crop mode as a snapshot wide angle with pretty much perfect correction (Adobe’s own Sony profile for APS-C), for videos too.

– David Kilpatrick

DK's ramblings, Lenses - E mount, NEX System, Photo Techniques, Sony Digital Cameras, Sony Digital Csmeras, Uncategorized

Sigma ultrawide zooms – old and new 12-24s versus 8-16mm

Posted on August 6, 2012 By David Kilpatrick

For almost a decade the Sigma 12-24mm full frame ultra wide angle zoom has been unrivalled by any other makers – not Nikon, not Canon, not Tamron, not Tokina, not Sony. No maker has ventured where Sigma went, to the extremes of over 120° coverage combined with well corrected straight line geometry.

Today, the original 12-24mm is in its fourth incarnation, having progressed through EX to EX DG (digital) and then with added HSM hypersonic motor focusing, which never arrived for Alpha mount in the original design. The fourth version is an entirely new design, and does have HSM for Alpha. It is very similar to the new 8-16mm design, introduced three years ago for APS-C cameras, which also offers HSM focusing in Alpha mount.

Update five years later, 2017: there is now a constant aperture 12-24mm f/4 ART lens. This is a completely new design and has an almost-perfect performance, especially in terms of corner detail wide open. I’ve tested it in Cameracraft magzine. However, I did not have the various older models to make direct comparisons. The MkII remains available as the current non-ART, lower priced Sigma option.

Here you can see, from left to right, the EX DG 12-24mm f/4.5-56, the DC 8-16mm f/4.5-5.6, and the DG HSM II 12-24mm f/4.5-5.6. Don’t be fooled into thinking the original is wider in diameter, it actually shares exactly the same lens cap module as the new design; it’s smaller and around 100 grams lighter. Both the 8-16mm and new 12-24mm are surprisingly solid items.

First, we’ll look at the difference between old and new 12-24mms. I have used the old one in several versions on several different camera makes. and I’ve never had one which was truly sharp at all point across the frame wide open. The field is not perfectly flat, and autofocus modules are very bad at getting an exact focus at 12mm. Combined with lens mount tolerances, sensor flatness problems (mostly in Canon full-frame, which historically have not had very ‘plane’ sensors), sensor parallelism problems (all makes, Sony not excepted)… it was always a good idea to stop this lens down to f/11.

How bad is that? Perfectly normal for any lens covering over 85°. Even the best large format lenses, single focal lengths like Super Angulons, have always been used in the awareness that full aperture is for focusing and you stop down to between f/11 and f/32 for the actual shot. On 35mm format digital, using anything much below f/16 is counter productive for sharpness and my normal choices on the Alpha 900 have been f/10, f/11, or f/13.

The good news is that the latest version has a different kind of field flatness. The old one tended to have a zone, like a doughnut, of closer effective focus surrounding a sharp middle. At 24mm, where this older lens performed at its worst, this zone was pushed out to the far edges and could result in the corners looking softer than they do at 12mm. The new one has a simple barrel distortion in place of a wave-form distortion, and along with this goes a simple curvature of field.

The bad news is that the overall level of distortion is much higher than the old design. At 12mm, it’s close to needing the fingers of two hands. Adobe Camera Raw had a correction profile for this lens from Sigma almost the day it became available. That profile fixed the distortion perfectly but leaves you slightly less of a 12mm than you’ve paid for, because it reduces the angle of view.

Here are some comparative views. First of all, I’ve used only 10 megapixels of the Alpha 900 frame, cropping from the top of a vertical shot, to get this architecturally correct view. This is like using the 12-24mm as an extreme 12mm shift lens on an APS-C camera. As and when we get a 36 megapixel Alpha full framer, the crop to do so will be more like 16 megapixels. This is the full frame:

Below you can see the crop used to 10 megapixels, and by rolling your cursor over the image, the change between a profiled conversion and a raw conversion with no lens corrections. On this crop it does not look extreme.

But this is a relatively kind way to use the new lens. Here is an example pushing straight lines into places where extreme wide angles don’t like ’em:

This is an uncorrected 12-24mm DG II HSM shot out of the Alpha 900 at 12mm. It’s not exactly what you want, and in fact, it’s not as ‘good’ as the old design despite being sharper. Hovering your cursor over the image shows the same raw file with the Adobe Camera Raw Sigma-generated Lens Profile (also works in Lightroom) applied. As you will see, straight lines have been restored along with even illumination. But – how much of that 12mm, 122° angle has been lost? Is it now really only a 12.5mm?

In practice, the new 12-24mm gives you a great range of creative choices when confronted with a building. Here is a revisit to the first subject, taken at different focal lengths, getting closer to the building with each shot:

24mm

20mm

17mm

15mm

12mm

When it comes to comparisons with the older design, the new one is much sharper at the edges. It does not need stopping down to f/16 to pull in the worst aberrations, though it does still display some around f/8 to f/11. Here’s an original 12-24mm EX DG design shot (12mm, f/9, vignetting corrected but distortion not corrected):

And here’s the new 12-24mm under the same conditions (small exposure difference due to changing light) processed similarly, without any geometric corrections:

On this shot, the corrugated barn sides have clean ribbing to the extreme ends, with some softening; on the old design, they begin to look a bit of a mess in the outer quarter of the frame.

Trying the 8-16mm extreme

But when doing these tests, I decided to throw a novelty into the mix. What if I put my 8-16m APS-C format Sigma DC HSM zoom on to the Alpha 900? Because it is not an Alpha lens, the 900 does not automatically crop the full frame. This is what I actually got with the lens set to 8mm:

And in Adobe Camera Raw, I just dialled up the Scale in Lens Correction to 146%, which blew up the central 12 or so megapixels of the frame to become a full 24 megapixel image:

And here, for comparison, is what the 12-24mm set to 12mm could produce:

This is a little tighter than the 8mm using the maximum I could get (including some extra image height), so the 8-16mm used this way can produce something closer to an 11.5mm full frame lens. However, I have not yet done the obvious – to get an engineer to remove the petal lens shade from the 8-16mm (it appears to be part of the front element assembly). This would enable even more angle without shading, and the possibility of square or 10 x 8 shape format crops.

What was particularly interesting about this experiment was the quality of the 24 megapixel file extracted from a smaller section of the Alpha 900 sensor by Adobe Camera Raw upscaling. Full size files are available to download for subscribers to Photoclubalpha – it’s well worth the $10 for a full year of access to any of the extras we provide. See the download links at the end of the article, which will become visible if you are a registered subscriber to the site.

The 8-16mm also achieves full frame coverage on the Alpha 900 when set to 16mm, though with fairly marked vignetting:

Here are some more samples from the 12-24mm DG II HSM: first, 17mm at f/8 – no geometry correction:

Next, at 12mm at f/13 which on the A900 seems to be the limit for good detail sharpness without extra effort in processing:

And 17mm at f/22 – beyond the diffraction limit, but processed carefully for detail:

And 12mm at f/9, an optimum setting for detail with plenty of depth of field for this subject:

So, what was my own decision? I own the 8-16mm and an Alpha 77. That’s what I use for travel and general work. I own an original EX DG 12-24mm. I decided not to buy the new 12-24mm because I concluded that the 8-16mm used on APS-C was effectively as good. The angle is not quite a match for the 12-24mm on full frame, as APS-C is not a true 16 x 24mm. For those occasions where a 12-24mm on full frame is needed, I’m nearly always able to work on a tripod at f/13 and focus manually (which overcomes most of the issues with the earlier lens). Since it needs less drastic geometric correction, it offers a very small angle of view advantage over the new lens in return for the risk of poor sharpness if not used well stopped down. I have no doubt the new lens is better, but it’s not £400 better which is what the ‘trade-up’ would cost – and the old lens is lighter and smaller, which I appreciate.

The test made me even happier with the 8-16mm, especially with the thought that some modification could make it a unique lens to use on the Alpha 900 or a future full frame EVF model (A99). After doing these tests, I decided it was not necessary to take the Alpha 900 and a 12-24mm despite the investment in two weeks’ shooting in the Sierras and Pacific Coast of California – the A77 and 8-16mm would do everything I needed.

But for those buying a 12-24mm, for full frame on any system, the new Sigma represents even better performance than the 8-16mm (better edge and corner sharpness at one stop down from wide open) and has none of the failings of the older lens even if it does need more post-process geometry correction.

Download full size images [private] 24 megapixels 12-24mm EX DG at 12mm f/9 Download Link
Download full size image 24 megapixels 12-24mm DGII HSM same as above Download Link
Download full size image 24 megapixels 8-16mm lens scaled to 24 megapixels from A900 ‘crop’ Download Link
Download full size image 24 megapixels 12-24mm DGII at 12mm compared to 8-16mm at 8mm cropped Download Link
Download full size image 24 megapixels 8-16mm at 16mm filling full A900 sensor Download Link
Download full size image 24 megapixels 17mm f/8 fence example shot boat Download Link
Download full size image 24 megapixels 12mm f/13 sequoia tree example shot Download Link
Download full size image24 megapixels 17mm f/22 boat Download Link
Download full size image24 megapixels 12mm f/9 riverside tree Download Link [/private]

To check the weight, specifications and other details of these three lenses we suggest you visit Sigma’s own site – for the new 12-24mm, here’s the UK site info. And here is the 8-16mm, which they oddly don’t class under wide zooms, but under DC lenses.

You can check worldwide shipped prices from B&H Photo in New York.

– David Kilpatrick

DK's ramblings, Equipment Reviews, Lenses - Alpha Mount

David and Goliath? Nikon D4 dwarfs NEX-7!

Posted on April 3, 2012 By David Kilpatrick

Side by side on my light table (which collapses with a ‘pop’ when sixteen tons of Nikon is placed on it), and the NEX-7 is given the foreground role to avoid any accusations of using perspective to make it look tiddly.

I’m writing some reviews of the Nikon and other new professional DSLRs for the British Journal, so I won’t say anything about the Nikon’s rather wonderful 16 megapixel full frame sensor or its stunning low light performance. I hope when Nikon read my reports they’ll decide to send me to photograph in the Arctic Circle in December – there would be plenty of light for this beast.

This picture won’t be going to the BJP. I like it because these are equivalents. The Nikon’s 28-300mm VR is admittedly f/5.6 at the long end (and a vast amount better than any Sigma or Tamron 28-300mm or 18-200mm yet made). But otherwise, these are zooms with the same range of angle, both stabilised, both very quiet in both focusing and IS action, both very well-made.

And the cameras are both a real pleasure to use and produce 100% professional results. The difference is that if I stick the NEX-7 combo under my coat, I do not look like a shoplifter or terrorist with a concealed weapon of mass-perturbation.

Watch out for our NEX-7 review soon. I’m not hurrying and it may be a month or more.

– David Kilpatrick

Cameras (DSLR), DK's ramblings, NEX System

Sony DT 16-50mm f/2.8 SSM

Posted on February 14, 2012 By David Kilpatrick

I’m about to offend myself. I own this lens, and I know how upset owners of brand new lenses get when someone says it’s not perfect. Well, the 16-50mm SSM is far from perfect and if you know how to check out lenses, you’ll agree should you be lucky enough to own one. It’s a compromise. But I love it.

Here’s the problem; this lens has such soft corners and complex distortion at 16mm and f/2.8 that it makes the NEX’s legendarily reviled* 16mm pancake look like a Super Angulon in disguise. It’s got a curved field at 50mm and stopping down does not always bring distant scenes into perfect focus across the frame. It suffers from rampant chromatic aberration which just becomes a dead-sharp fringe on stopping down. *Not by me!

This shot was taken on a preproduction A77 and 16-50mm. I was not supposed ever to show it. But I know there is no fault with the shot, the pre-release gear was just fine. And I really like the minimum focus, at 50mm, at f/2.8!

Yet it also has exceptionally high central sharpness, great colour and contrast, and a lovely quality to its differential focus. That’s the old traditional English-language term for the context in which people over-use the term ‘bokeh’, and deserves to be revived. With f/2.8 to play with across the entire zoom range, you can use differential focus creatively. At medium settings, 24-35mm, the distortion disappears and the sharpness extends corner to corner wide open. You have to set it to 50mm to lose the edge.

More than this, the 16-50mm SSM is a video-tuned lens. Its natural host camera, the Alpha 77, crops the frame considerably when shooting HD video. The soft corners and even most of the distortion don’t get a look in, they are outside the video area. The standard and 3D pan modes of the A77 also crop out the problems. The focus action and silent supersonic motor of the 16-50mm are ideal for A77 video shooting with active AF (if you want it) during takes. The f/2.8 aperture allows the lens to be stopped down to the optimum f/3.5 used for movies and also for high speed (12fps) mode, and have no issues with aperture shifts if the focal length is changed.

The Carl Zeiss 16-80mm, left, is smaller than the Sony 16-50mm SSM.

After testing the lens, I decided to keep my 16-80mm CZ which is now five years old. It’s not just the different quality of image produced by the CZ coatings and design, or the very slighter better close-up ability (you can’t get quite as close but at 80mm the subject scale is a touch bigger on the CZ – the 16-50mm wins at 16mm, where getting two and half inches closer to the subject makes a real difference). The CZ is lighter, takes 62mm filters rather than 72mm, and is considerably smaller with lens hood size adding to the difference. Working in the field, it is a lens which can easily be held in the hand with fingers free to operate the lens-mount release button, hold a rear cap, or even another lens – the usual juggling of two lenses which photographers get used to.

With lens hoods fitted, the overall relative sizes become more obvious. The SSM lens has an attractive metal front ring, a new trademark of higher-end Sony lenses, shared with the 70-400mm G.

The 16-50mm is at the limit of diameter, shape, balance and weight to be safely gripped with another lens in the same hand, even briefly during the process of swapping over. That’s not to say it is cumbersome, just that the 16-80mm is faster and more secure to work with because it’s that little bit smaller and lighter.

Once on the camera, I have to say I like the overall balance created by the 16-50mm. It tends to help the A77 hang lens-down, a position I prefer with the camera under my left arm and the strap over my shoulder. The zoom action is super-smooth and well damped, and also has a lock which operates at 16mm to prevent gravity-fed creep, and keep the action firm in future.

No creepy zooming – thanks to Royal Mail, and their neat Sony-coloured rubber bands which are a perfect fit to go on the CZ 16-80 and make the zoom action super-smooth and stay put!

My CZ is now well used and over-free in action. A rubber band to go over the front end of the zoom ring is the cure! You can get proper broad Alpha-ish orange silicone rubber ones from Lens Band as well as the free orangey-red ones used in the UK to hold our postal deliveries together. My way of using a rubber band is not quite the same as Lens Band’s method, it goes over the flush seam between zoom ring and lens barrel on the 16-80mm and it doesn’t just hold the zoom, it smooths the zoom action.

The zoom lock on the 16-50mm was missed from the 16-80mm… missed by all owners, that is. The 16-50mm has a type of raised moulded marking. Durable? Maybe not. The similar raised ‘P’ on my A77 mode dial is now a ‘D’ having lost its stalk.

The best shots I’ve got from the 16-50mm are as good as the best from the 16-80mm, but I can trust the CZ more in the 35-80mm range. From 35-50mm the SSM becomes increasingly soft and sharpness towards the edges of the frame can be poor. At first I thought this was only at full aperture, but shots at apertures like f/5 and f/7.1 were affected. I compared my own lens with two pre-production Sony samples I had used months earlier; we were told not to release images taken with these. The degree and type of sharpness loss was identical, enough for me to conclude this is a characteristic of the lens and not a coincidental case of rogue lenses.

Major plus points for the 16-50mm include focus accuracy, which is much better than the 16-80mm on most Alpha bodies. The f/2.8 aperture activates higher accuracy sensors, such as the Alpha 700’s central point and the extended range of the 11 cross sensors of the Alpha 77. When used on the Alpha 580 for live view pre-shot AF, or on the NEX models with the original LA-EA1 contrast-detect AF adaptor, both focus speed and accuracy are optimum.

The SSM lens has an AF/MF switch but no on-lens button control. Direct Manual Focus is supported and unlike SAM (conventional in-lens motor) lenses, the supersonic drive is not damaged by moving the focus ring without engaging MF.

Despite the large area of glass, the 16-50mm is no more prone to flare than the 16-80mm. The new Sony coatings used for this lens (water and oil/dirt resistant, very hard, similar to Nikon’s NanoCrystal) do a great job. And, of course, they are part of the final reason I am keeping this objective. It’s weatherproofed to some degree, as is the Alpha 77 body. Reports vary between dowsing with a bucket of water without harm, to reluctant use in slight drizzle. I think I’ll get myself a Sigma EX DG filter for my lens, as these have the same coating now and they are about the best slim-mount UV filters made for optical quality without paying Hoya Pro1 Digital prices.

Also, with the 72mm filter thread, there seems to be less need for a super-slim filter. The CZ lens suffers from very strong mechanical vignetting at both ends of the scale, producing dark corners at 16mm or 80mm alike. At 16mm, depending on the position of the SSS/AS sensor-based stabilisation, a dark corner can be well enough defined to need cloning out or the image cropping. The 16-50mm SSM has no such issues. Not only is optical vignetting well-controlled, the mount does not create any dark corners.

These dark corners are created by adding vignetting and grads in raw processing. The 16-50mm, at 24mm, turns in great shadow to highlight detail without a hint of flare; 1/50th at f/9, ISO 100, hand-held with SSS – mid-January in the Scottish Borders. When I pulled up to shoot this, a car with two camouflage-kitted big Nikon and Canon multi lens ‘serious enthusiast’ shooters pulled in alongside. They were still struggling with tripods, a kissing-gate, a stone wall, lenses and car by the time I’d got the sunray shot (which disappeared in seconds) and left. I just carry my Alpha 77 – but then, I’m not a ‘serious enthusiast’ and my ideal camera would be invisible and with me all the time. I’m a panda – sees shoots and leaves.

Though Sony owners may be reluctant to admit it, the SSS mechanism can decentre the sensor and if the lens coverage is so tight it barely covers the corners of the frame (16-80mm and 16-105mm both guilty) you can get the occasional asymmetric dark corner. I’ve never seen this yet from the 16-50mm. But when I check the 16-80mm against the 16-50mm using the Alpha 900 full frame finder to examine the image circles, if anything the 16-80mm has more apparent clearance round the extremes of APS-C, with a softer gradation. The 16-50mm has a tight exact circle.

I have also checked the way the 16-80mm and 16-50mm focus as you zoom. Though the CZ is not perfectly parfocal. That term describes a zoom which retains exactly the same focus point, as you zoom. Video and TV camera lenses are parfocal, otherwise, the focus might ‘go off’ during a zoom. The CZ is nearly parfocal, just a touch varifocal. That’s the opposite term, and means a zoom which changes the focus as you change focal length. At one time, varifocal lenses were not actually called zooms; they date back to the 1920s, and J H Dallmeyer’s adjustable telephoto lenses. Konica made a famous 35-100mm f/2.8 Varifocal in the 1970s.

Silent focus, silent A77 camera (almost), 16mm and ISO 800 at f/3.2 – with ACR profile correction. Café society, Hawick.

The 16-50mm is either a perfect parfocal zoom, or so close you will never know. It is possible to focus at 16mm, and zoom in to the subject. This can only happen with very accurate focus, and a parfocal zoom. Try it with the 16-80mm CZ and you will see the image go out of focus, not to mention clicks and jumps in brightness changing as the aperture adjusts (that’s because the CZ is a variable maximum aperture lens, f/3.5-4.5). The 16-50mm can zoom during video, in or out, without losing the original focus point and without any brightness change or aperture adjustment.

Now you may understand why I want to keep this lens even though – unlike some enthusiastic new owners – I find that its sharpness across the field is not actually as consistent as the CZ. It is a far better overall match to the Alpha 77 especially for video work. But in January, I chose the CZ in preference for a week abroad, and I would most likely do so again.

The Alpha 77 (and 65) include built-in correction profiles for this lens. They are so effective that when I first saw JPEGs from it, I thought the geometry was perfect. If you intend to use the lens for JPEG and movie shooting, any criticisms can be moderated. The correction profile can not improve sharpness, and it does change the effective focal length slightly so than you don’t get a true 16mm.

This is a straight-on shot of the Adobe chart used (not this way, shot nine times per full frame) for profile creation and it shows how very bendy the 16mm f/2.8 setting is at this range, the target is A2 size. Click image to see full size.

This is the same, but JPEG with the in-camera correction enabled.

This is the same, with the Adobe Lens Profile I have created and sent to Adobe, applied in raw conversion of the first example. Please note that the Adobe profile applies to shots taken at three times this distance or more – these profiles, like the in-camera profile, are never much good at rigorous correction of geometric targets shot a couple of feet from the lens.

For Adobe Camera Raw, I have made a profile for the lens which covers three apertures (f/2.8, f/5.6, f/11) and three focal length settings (16mm, 24mm, 50mm) between all of which ACR will interpolate correction values. Because the extreme corners of the image go so much out of focus when shooting the target (refocusing ruins the profiling process) I don’t think this profile handles chromatic aberration as well as it could. The profiling program needs a sharp image of the RGB colour channels to work out their relative scale, which is how CA is corrected. Applying 150% CA correction, instead of the default 100%, seems to improve the conversion.

Here is an uncorrected real-life shot on the 16-50 and 16mm, 1/125th at f/9, ISO 200 (click image for full size 24 megapixel view, and note the chromatic aberration at the left end of the shot especially).

This is the same raw file processed using the Adobe Lens Profile I have produced for the lens.

You can dowload from here the 16-50mmA77rawAdobeLensProfile, hopefully it will also become available from Adobe’s user-created download area. Unzip the file to extract the .lcp file, and place this in your Application Support/Adobe/CameraRaw/LensProfiles/1.0/Sony directory. You require Photoshop CS5 to use the profile.

So what is my conclusion? I do not agree with some of the over-the-top reviews including one to be found on the Sony store USA site claiming it’s the best zoom of this range and aperture for any system. It is not, you get more than you pay for (much less than a lens of this specification might cost from others) but not an optical miracle. You get a very well designed optical compromise housed in a particularly good mechanical design. I would compare it favourably with Olympus’s waterproof ‘Top Pro’ range fast lenses for 4/3rds. I think it can claim to match Canon’s 17-55mm f/2.8 and Nikon’s similar lens, I’ve used both and the Sony is rather neater. It’s probably a little better than the Pentax/Tokina 16-50mm f/2.8, which it most resembles but definitely is not related to.

It’s different from the CZ 16-80mm, not better or worse; it has a different mix of good qualities and failings. The obvious competitors are Sigma’s 17-50mm f/2.8 OS and the Tamron 17-50mm f/2.8. The Sigma offers Optical Stabilisation. The Tamron is now an older design, replaced by a new VC stabilised version for other mounts, but still issued without stabilisation at about 60% of the price of their VC versions, for Alpha. It is the lowest-cost option in this range.

The Sony Alpha SSM 16-50mm f/2.8 DT lens is supplied with rear cap, 72mm lens cap, and bayonet petal hood. It does not come with a case or pouch. My lens was purchased ‘white boxed’ – that is, split off from an Alpha 77+16-50mm kit by a dealer and priced accordingly. The lens is only available with the A77, or as a separate item; it is not currently offered as a kit option with the Alpha 65 or other models.

– David Kilpatrick

Check the current price from B&H Photo Video – remember, B&H ship worldwide and for the UK buyers, offer a UK service.

Technical Data (Sony information) amended to remove nonsense

Lens Type : Standard Zoom
Focal Length 16-50mm (35mm equivalent 24-75mm)
Lens Mount Type : Sony A-mount, SSM in-lens supersonic motor focusing, electronic coupling
Aperture (Max.) : f/2.8
Aperture (Min.) : f/22
Filter Diameter : 72mm
Lens Groups-Elements : 13 groups, 16 elements
Minimum Focus Distance : 12″ (30cm)
Distance Encoder : Yes
Distance Scale: Yes
Angle of View: 83°-32°
Non-rotating Filter Thread : Yes
Aperture : 7 blades (Circular aperture)
Lens Weight : 20.4 oz (577g)
Maximum Magnification : 0.2x
Dimensions (Approx.) : 3-1/4 x 3-1/2” (81 x 88mm)

Compare the 16-80mm Carl Zeiss technical data:

Lens Type : Standard Zoom
Focal Length 16-80mm (35mm equivalent 24 – 120mm)
Lens Mount Type: Sony A-mount, in-body motor focusing via mechanical drive coupling
Aperture (Max.) : f/3.5 – 4.5
Aperture (Min.) : f/22 – 29
Filter Diameter : 62mm
Lens Groups-Elements : 10 groups, 14 elements
Minimum Focus Distance : 14.4” (36cm)
Aspheric Elements : 2 aspheric
Distance Encoder : Yes
Distance Scale : Yes
Angle of View: 83°-20°
Non-rotating Filter Thread : Yes
Aperture : 7 blades (Circular aperture)
Lens Weight : 15.7 oz (445g)
Magnification : x 0.24
Dimensions (Approx.) : 2 7/8 x 3 3/8” (72 x 83mm)

Equipment Reviews, Lenses - Alpha Mount

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