Amateur Lens Test: Sigma 30, Zuiko 28mm F2, Sel1855 kit & Zeiss Distagon 28mm F2.8

Started Nov 2, 2012 | Discussions thread
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Gomez Garcia Gonzalez Regular Member • Posts: 172
Amateur Lens Test: Sigma 30, Zuiko 28mm F2, Sel1855 kit & Zeiss Distagon 28mm F2.8

The candidates line up for deabte...

I had a spare afternoon and temporarily find myself with four lenses in the 28-30mm range that fit my NEX 7. Time for a lens test to see how they stack up!

I'm not a professional tester or even an experienced tester, but I wanted to find out how these lenses compared and thought that people on this forum may be interested in my results. Further disclaimer - clearly I've only tested one example of each lens, the ones I own in fact. Other copies of these lenses could yield quite different results.

The Lenses (and my expectations of them):

Sigma 30mm F2.8 e-mount - this lens is well-regarded on this forum and is thought to be unusually sharp right across the frame, for it's price, at least. Though many consider it THE sharpest e mount lens bar none. I expected it to win easily at F2.8 and be at least as good as the others from then on. It is the smallest and lightest of the four with a plastic build and it rattles when unattached to a camera.

Olympus Zuiko OM 28mm F2 - this lens is pretty highly regarded amongst OM lenses, though perhaps not as highly as the 24mm. One tester who had tested almost all the OMs describes it as "one of the sharpest zuiko lenses". The F2 zuikos were thought to be the professional grade lenses of that system, in any respect. I wanted this lens to do well, it has a lovely form factor on the Nex and balances very nicely even with the adapter. It is solidly built out of metal but is still quite light and about the same size as the kit lens with the adapter attached, despite being the fastest of the lenses here.

​Sony kit lens, for this test we'll consider it a 28mm F4​ - I almost never use this lens, except for video. But I've found these kit lenses to be quite decent in the 24-30mm range. This is the better one of two I've had. It only enters the race at F4, which in my eyes puts it on the back foot as I'm interested in a lens of this focal length being a low light option.

​C/Y Zeiss Distagon AEJ 28mm F2.8 ​- This lens is the biggest and heaviest of the four (though they there isn't much between this, the zuiko and the kit in reality). While nowhere near as lauded as it's big brother, the F2 Hollywood Distagon, it has a very good reputation amongst the Contax crowd. Word is that it isn't great wide open but is impressively sharp from around F5.6. I was curious to see how it competed with the sigma at F8.

The Setup: I shot a landscape scene from my balcony with the horizon on a diagonal so that I might compare centre, upper left corner and lower right corner in each image. Everything in the shot was at infinity focus, so as long as I got that right then there should be no focus errors. Camera was tripod mounted and all lenses had filters removed except the Distagon, where the original contax filter is hard to get off. The zuiko and kit had their hoods fitted, though the sun was well out of the shot. This is a pretty pure landscape test, with some high contrast edges to show up any CA issues and a range of houses of different colours, plus a few business signs to really pixel peep sharpness on. I shot each lens at the apertures available from F2, F2.8, F4, F5.6, F8 and F11.

After doing the comparisons for this test I did a quick test of a painting at 1m, only at F5.6. to see if there were any obvious differences in performance at that distance.

I also did a quick informal bokeh test to see if there were any huge differences between the lenses in that regard.

I didn't test distortion because it's not a big factor for me and I was pretty sure the primes would all be much better than the kit, which I have a profile for.

Images were compared at 100% after importing the RAW files into LR4.2. No PP occurred besides the default LR import RAW sharpening, which was the same for all images.

I gave each lens three scores for sharpness respective to the upper left corner, centre and lower right corner. The scores were from A+ for impeccable sharpness and C- for unuseable rubbish. For reference, the worst centre score in the test was a B+, which I consider just sharp enough to use. So none of these lenses take shots at any aperture where the centre is so poor that I must immediately banish them from my Lightroom catalogue in disgust. Good stuff. Corner scores were slightly weighted, so an A corner would still not be quite as sharp as an A centre. Having said that, no image scored an A+ corner so I perhaps could've been more lenient in this regard.

I also made a contrast comment for each image and gave a chromatic aberration score between 0-5. O meant no fringing was perceptible at 100%, 1 would mean someone picky (that's me) could see it at 100% but would necessarily bother to fix it, 2-3 meant visible and easily fixable without any real image degradation. 4 or 5 would count towards image quality in an actual way, even with fixing, though no image was graded worse than 3 so no real problems with any of these lenses from this test at least.

The resulting scores are below, I'm not going to crop, export and upload all 32 images from the test. That would exceed my patience and upload limit, so you'll have to take my word for it.

The Results

Aperture                         Zuiko              Kit             Sigma             Distagon

low                xxx              xxx                   xxx           contrast

F2                                B-, B+, B-           xxx             xxx                    xxx          sharpness

3                 xxx              xxx                    xxx              CA

Zuiko wins, no contest. Image is glowy and low contrast, but the centre is actually reasonably sharp. This lens produces useable images at F2.

low/normal       xxx             normal                 high

F2.8                             B-, B+, C          xxx            B+, A, A-            A-, A/+, B+

3                   xxx                3                       1

Zuiko's contrast improves but the image is no sharper despite appearing better due to contrast improvement. Despite its head start, it lags behind the Sigma and the Zeiss, the latter of which which has impressive contrast wide open and is just a hair sharper than the sigma in the centre. The Zeiss shows far less C/A than the other two. Both the Sigma and Zeiss have one corner weaker than the other and the fact that they are opposite corners suggests this isn't tester error (one corner was more distant from the camera than the other). Kit lens still hasn't turned up to the party.

low/normal            normal            normal              high

F4                            ​B-, A-, B              B, A, B+           B+, A+, A-     A-, A+, A-

2                         2                    3                     1

The Zuiko has improved, but is still perceptibly poorer than the kit lens both in the centre and corners, despite that lens now being wide-open while the Zuiko is two stops down and should be sharpening up nicely. The centre of the Sigma has improved and matches the Distagon, which has also marginally improved in the centre and weak corner. Interestingly, the Sigma displays the worst C/A of the four at this aperture, though it's not bad enough to be a real concern.

normal           normal/high         normal             normal/high

F5.6                         B-, A+, B+          B+, A, A            A-, A+, A           A-, A+, A

1                  1                       2                       1

The Zuiko finally gets going in the centre and is now impressively sharp, though the corners lag perceptibly behind. The kit is pretty good, though not quite as good in the centrea s the other three. The Sigma and Distagon are now almost inseparable, though the Zeiss has a contrast advantage so it appears superior. The Sigma has worse C/A than the other three, all of which are now at a negligible level.

normal/low                normal/high         normal            normal/high

F8                       B-, A+, B+                   A-, A+, A         A-, A+, A          A-, A+, A

1                               1                   2                       1

The corners on the zuiko show no sign of speeding up, despite my hopeful encouragement. The other lenses are all pretty even, with contrast nods going to the Zeiss and the kit over the Sigma, which still fringes worse than the competition. I accept at this point that the more distant upper left corner may be scoring consistently worse than the closer lower right corner dut to my lack of objectivity in scoring houses at different sizes. This perhaps makes the Distagons' advantage over the Sigma in that quadrant at F2.8 more significant?

low/normal                   normal          normal                 normal

F11                    ​B+, A+, A-                    A, A, A           A, A+, A           A, A+, A

1                                1                   2                       1

Lo and behold, a bit more depth of field and the distant corners improve all around. The Zuiko seems to have less contrast again, could this be diffraction setting in? The kit slips a bit in the centre but is nicely uniform. The Sigma and Zeiss are still superior in the centre, though the Zeiss has lost its contrast advantage at this aperture.

Close focusing test: These lenses all focus to about 30cm (the Zeiss goes a bit closer to about 25), but this test was done at 1m for practical reasons. The results generally match the landscape test in terms of centre and corners, though the Sigma and Zeiss swap places at the top, with Sigma ever so slightly sharper in the centre at this distance. The Zeiss still has better contrast though.

Bokeh test: I didn't even bother testing the kit, it's a zoom and only goes as wide as F4 so it's not really a lens you go to for arty bokeh look. The other three all gave smooth bokeh at F2.8 where they were tested (the Zuiko was perfectly nice at F2 also), though the Sigma was slightly harsher than the Distaogn and Zuiko.

Colour Rendition: The Zuiko was noticeably warmer than the other three and quite pleasing in this respect. The Zeiss was also very good, aided by it's excellent contrast. The Sigma was a bit vapid and the Sony kit is a little cold and blue for my liking. While this aspect is easily fixed in PP, I think there is still a point in favour of the 'Z's over the 'S's.

To conclude: I was twice disappointed in the peformance of the Zuiko. It's a lovely feeling lens on the Nex and my OM/Nex adapter had been sitting idle since I got rid of my Zuiko 135mm F2.8 (which lost out to the Contax Zeiss Sonnar of the same specs, despite being more trim). If it was closer to the others in performance from F2.8-F11 it would be a keeper with it's useable quality at F2 combined with nice size and build quality. Though I should point out that I think the aperture ring being so close to the focus ring and both being so small is actually a handling disadvantage, though some cite this as a bonus. After the first round of shots the Zuiko was so far behind in the centre at F5.6 that I knew something was wrong, so I reshot those images. It turns out that it is very easy to move the focus ring when you grip the aperture ring and turn it, so if you are focusing at a wider aperture and then stopping down you can lose focus quite easily. I was hopeful the second set of images would push the Zuiko into contention and while they were significantly better they were still behind the others. I'd love to keep this lens so I could use it a F2, but I can't justify owning all these lenses and I'd always be disappointed with it's centre sharpness between F2.8-F5.6.

The kit performed as I expected. It's very useable at this focus length, but you can do better if you are a real stickler for image quality and especially if you want something very good wider than F8. It's not going anywhere, I need it for video.

I expected big things from the Sigma and it didn't disappoint, though I was surprised to see it bested by the Zeiss at F2.8, where I thought it would hold a solid advantage. My copy seems to be slightly weaker on the left side. While its sharpness characteristics are very good, its colour rendtion, contrast and chromatic aberration performance are all behind the classic Zeiss Distagon, at least to my eye. It does hold an autofocus capability advantage over that lens, but manual focus at 28-30mm is hardly taxing (that is certainly a different story at longer focal lengths than this, but I feel at 30mm autofocus is not a huge advantage).

The Zeiss was surprisingly good wide open. I thought it might compete with the Sigma at F5.6 and 8, but it was surprsing to see the biggest difference between the two was at F2.8 and in the Zeiss' favour. This lens is also a great example of the Zeiss look it would seem, its effortless contrast meaning the SOOC images look superior to the others even if it is not actually any sharper (shock horror!). It has a lovely build quality and it's aperture ring feel is beyond compare.

Final verdict: There's not too much difference between the Sigma and the Zeiss that can't be closely evened up in post and the size and autofocus advantage of the Sigma lens mean it would likely be the one I would keep if it weren't for the sel35f18 on it's way. But I don't think the Sigma would get used so much if the faster and OSSed Sony lens is as good as hoped by many here. A 30mm and a 35mm is more than I can claim to need. Indeed, a 35mm and a 28mm may still be a luxury, though the idea of a faster and slightly longer autofocus lens to match with a wider lansdscape lens which may one day excel on a FF Nex is tempting indeed. For this reason I'll likely sell the Zuiko and Sigma and hold on to the Zeiss.

This said, if the 35mm lives up to expectations and I can afford it despite all this lens trading, a 24mm manual lens may well make the most sense to slot between the 35mm and my Samyang 14mm F2.8. So perhaps a Zuiko 24mm F2.8 or Canon FDn 24mm F2.8 is in my future and could be compared to the Zeiss at some point. Heck, both of those lens comes in a well regarded F2 also...

Comments and questions in regard to this test are welcome. Thanks for reading!

PS: A Contax G Zeiss Sonnar 90mm F2.8 vs Contax Zeiss Planar 85mm F1.4 vs Canon FDn 100mm F2 comparison may well be forthcoming once my FD/Nex adapter turns up from China (could be months!).

 Gomez Garcia Gonzalez's gear list:Gomez Garcia Gonzalez's gear list
Sony Alpha NEX-7 Sony Alpha a99 Sony 135mm F1.8 ZA Carl Zeiss Sonnar T* Sony 24mm F2 SSM Carl Zeiss Distagon T* Carl Zeiss Distagon T* 2/28 +4 more
Panasonic Lumix DMC-F5 Sony Alpha NEX-7
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