LA-EA3 - Cameracraft

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