Sigma launch world first 28-45mm f/1.8 full frame zoom

Today Sigma announced their latest E and L mount DG DN Art series wide to standard zoom with a constant maximum aperture of f/1.8. The focal length range from 28 to 45mm on 24 x 36mm full frame covers 75° to 51°.

It’s a large lens taking 82mm filters as does the new 24-70mm f/2.8. It is six inches/151mm long and and does not extend during zooming. It weighs 950g (E-mount) and focuses down to 30cm for quarter life size 1:4 close-ups at 45mm. It has 18 elements in 15 groups, with three aspherical and five super-low dispersion.

No previous mirrorless lens from Sigma has been similar but two have a good reputation in DSLR fit, from 2015. The 24-35mm ƒ2 DG HSM Art weighs only 20g less, takes the same filter size and is smaller by the difference between mirrorless and DSLR body depth. The 18-35mm ƒ1.8 DC HSM Art is for crop format (1.5-1.6X) not full frame.

The 28-45mm comes with a new type lens hood, front and rear caps and a padded zip case. It goes on sale on June 20th for £1299 inc. VAT, UK retail. Sigma claim ‘sharpness and clarity comparable to that of a prime lens throughout its entire zoom range’. A de-clickable physical aperture ring stops the 11-blade rounded diaphragm down to f/16. A function button, AF-MF switch and zoom lock complete the controls.

Our review of the 24-70mm f/2.8 DG DN Art will appear in the July/August edition of Cameracraft, it’s being tested right now. First impressions: crystal clear images, good handling for a large zoom, usual top-grade Sigma case/strap/new-type hood and excellent value. We expect the 28-45mm to appear in a later issue.

See: https://www.sigmauk.com

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

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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.

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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.

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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.

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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!

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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.

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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.

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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.

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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.

Roughting Linn, Northumberland - the waterfall.

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 –

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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).

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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

New 'micro 4/3rds' system announced

Tokyo, 5 August 2008 – Olympus Imaging Corporation (Olympus Imaging) and Matsushita Electric Industrial Co., Ltd. (Panasonic) today announced joint development of technologies and devices for the “Micro Four Thirds System standard,” a new standard that extends the benefits of the Four Thirds System standard for interchangeable lens type digital camera systems by enabling dramatic reductions in size and weight. Under the terms of an agreement between the two companies, they will work jointly toward commercial production of significantly lighter and more compact interchangeable lens type digital camera systems.

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