Lenses and Optics

Sony FE 90mm f/2.8 G OSS Resolution Test

Published May 4, 2015

We got a pre-release set of Sony FE 90mm f/2.8 G OSS Macro lenses in for preliminary testing last week, and I was kind of excited about this lens for a couple of reasons. First it simply gives me a nice short telephoto prime option that has been lacking in the lineup (although the Zeiss 85mm Batis lens will be coming along fairly soon). Second, it gives me a true macro lens at the focal length I prefer.

Image Courtesy Sony, USA

 

I hoped that the combination of a good macro lens with the A7r sensor would turn out to be a winner. We used our Imatest lab to compare Sony 90mm f/2.8 G OSS lenses mounted to¬†Sony A7r cameras, and compared them with Canon 100mm f/2.8 IS Macro lenses shot on Canon 5DIII cameras in our Imatest lab. (For those who are curious, we can’t test Sony E mount lenses on an optical bench because the electromagnetic focus system requires electrical power to operate. Until we do some really geeky, overly complex engineering modifications, the optical bench isn’t an option for Sony E mount lenses.) It would have been nice to also compare with a Nikon D810 and Nikon 105 f/2.8 Micro lens, I know, but our time is limited.

Overview of the 90mm f/2.8 G OSS

First of all, if you’re used to Sony E mount lenses being smaller than their SLR counterparts, you’ll need to get over that. The 90mm lens is very similar in size to the Canon 100mm f/2.8 IS and other SLR macro lenses in this focal range.

 

Canon 100mm f/2.8 IS on 5D III (left) and Sony 90mm f/2.8 on A7r (right). Lens rentals.com, 2015

 

If you’d like the numbers for comparison, I’ve put them in a table.

  Sony 90mm f/2.8 OSS Canon 100mm f/2.8 IS L Nikon 105mm f/2.8 Micro VR
Price$1,098$899$879
Weight (lb.)1.321.381.58
Length (in.)5.144.844.9
Filter size (mm)626762
Min. Focus Dist. (in.)111212
Aperture Blades999
Elements/Groups15/1115/1214/12

The Sony is a bit more expensive, but that’s not unusual for a new release. Otherwise they are pretty similar in specifications.

Test Results

We tested these in our Imatest lab but at two different focusing distances and with two different charts. Remember, the higher resolution of the A7r camera will make the system resolution higher. My thinking when making this comparison was if the Sony lens wasn’t up to the standards of the Canon (which is arguably the best macro lens in this focus range), then the Canon system would be close to the Sony, despite the higher resolution of the Sony camera.

The tables below shows the MTF 50 results averaged for 6 samples each of the Sony 90mm f/2.8 OSS on a Sony A7r compared with 6 samples of the Canon 100mm f/2.8 IS L on a 5D Mark III.

Our first test was using a standard Imatest setup shot at a distance of about 20 feet.

 Canon 100mm f/2.8 IS LSony 90mm f/2.8 G OSS
Center1580 lp/ih2300 lp/ih
Average1340 lp/ih1665 lp/ih
4 Corner avg. 1125 lp/ih1210 lp/ih

We then repeated the tests, using a high-resolution, back lit chart made by Imatest specifically for testing macro lenses. The focusing distance was now just under 2 feet. This doesn’t give us quite full 1:1 macro working distance, but it’s pretty close.

 Canon 100mm f/2.8 IS LSony 90mm f/2.8 G OSS
Center1540 lp/ih2210 lp/ih
Average1290 lp/ih1765 lp/ih
4 Corner avg. 1105 lp/ih1380 lp/ih

At both focusing distances the Sony system is clearly out resolving the Canon system. We would expect that, to some degree, given the higher resolution Sony sensor. But the difference was, quite frankly, surprising to me. It would seem to indicate the new Sony 90mm Macro lens performs at least as well as the Canon 100mm f/2.8 IS L, from a resolution standpoint, anyway.

Summary

Please don’t take this out of context. These are simply Imatest MTF50 numbers. By that standard the new Sony 90mm f/2.8 G OSS Macro seems to be a superb addition to the E mount lineup, and the lens on an A7r should provide superb resolution. We’ll have to look at more in-depth, hands on reviews to see how it actually performs in the field, what the bokeh looks like, how well the OSS performs and a host of other factors to decide how great (or not) the lens performs in the real world. But these preliminary results look very good.

 

Roger Cicala and Aaron Closz

Lensrentals.com

April, 2015

Author: Roger Cicala

I’m Roger and I am the founder of Lensrentals.com. Hailed as one of the optic nerds here, I enjoy shooting collimated light through 30X microscope objectives in my spare time. When I do take real pictures I like using something different: a Medium format, or Pentax K1, or a Sony RX1R.

Posted in Lenses and Optics
  • Igor

    I can not believe that brand Sony adapters are that poor quality. Even if it was the case, you could measure the resolution at least in the centre of the frame. How it compares to that in the corners we know from the test of the Canon lens on the Canon body.

  • Thanks for the work!
    One question: these measurements are at f/2.8, right?

  • Wow, that’s a BIG difference. Let’s see how the 5Ds changes that, but WOW.

    Do you plan to test the 28mm f/2.0? With and without the adapters? It’s a very intriguing lens…

  • Lee Saxon

    So is not being able to use the optical bench a big issue for your maintenance and calibration of lenses? Are you going to be trying to build something to fix that?

  • Raul Sanjur

    Why did you use the a7R instead of the a7 or a7II? The difference in sensor module resolution affects results. You should have had the Canon 100mm on the a7R too or make a fair comparison and test it on the a7 (or a7II).

    Even on DXO, you can see the difference in results between a lens tested in a a7 and a7R.

  • Roger Cicala

    Steve, that is my plan and why I want this data.

  • Roger Cicala

    Kris, nope, we’ve tried. Remember the critical measurement isn’t the outside thickness. It’s from underneath the flange mounts of the adapter on the camera side to underneath the flange of the lens. That’s really tough to measure with a micrometer.

  • Roger Cicala

    Lee, I agree, but the main goal of the test was to see how good the lenses were which meant stressing them with the A7r body. I got the lenses for a few hours from Sony for that express purpose. My bad was thinking the Canon lens was so great it would ‘close the gap’ so to speak. The A7 or A7II would have been a better comparison but I didn’t have time to do both. In retrospect, the Nikon D810 and 105mm Micro would have been a closer comparison than the Canon probably.

    Roger

  • Lee Saxon

    I get not having time to compare it to both the Canon and Nikon systems, but I’m confused by which you chose. A7r vs 5D3 is a big resolution difference. Either A7r vs D810 or A7 vs 5D3 seems like it would have given more balanced results.

  • Tom

    Please compare to the myth…the legend…the Minolta 100mm 2.8.

  • Kris

    Roger, you could measure the thickness of an adapter with a micrometer in several location around the circumstance to see how true it is. This way you should be able to find a good adapter for testing.

  • Oskar Ojala

    I found it interesting that in the center of the frame there was no contest, but the difference evened out a lot in the corners. Any comment on that? In APS-C sensor Sonys it always seemed hard to find lenses that perform well in the corners, so wondering if we’re seeing any hint of sensor issues here.

  • Asen

    I think this comparison just confirms that with any decent lenses you get more resolution froma 36mpix than from a 22mpix sensor

  • Gerard Butters

    Weilli – “The resolution of Sony G90/2.8 in the 4 corners increased in the short focusing distance. Is it normal?”

    Yes, it’s normal for a macro lens to work best at macro ranges. That’s pretty much the main point of them, so that’s the range the manufacturer optimises for.

  • Adam

    Goodness gracious, Uncle Rog, wasn’t it you who said ‘a rising tide lifts all boats’?

    Why on earth did you confound the comparison with such wildly different sensor resolutions? You already proved this before with your Canon v Nikon 24-70 comparisons between a 22 and 36 MP sensor.

    Surely adapting the Canon onto the a7R or perhaps running the Sony lens on a more resolution-appropriate a7 II would have been a better call.

    I just can’t support your endorsement of the Sony lens until that unbelievably-non-trivial consideration is addressed!

  • Steve Waldstein

    Ok, I’ll buy the adapter issue for your testing but taking that approach negates the big marketing hype everyone always uses for Mirrorless is “look you can adapt lenses” but testers refuse to do it. Also it appears testers always want to use the A7R and ignore that the A7 or A7II is a more appropriate resolution challenge. I own the 5DIII , A7II, 100mm f/2.8L and the Zeiss 100mm f/2 and I want to know how the lenses compare. Not just the sensors. Will you all committ to testing the canon lens family again when the 5DSr comes out? I won’t hold my breath.

  • Thanks, Roger. I get it now.

  • Roger Cicala

    Kiril, you see the setup I left, huh? Of course I’ll be repeating the test with the 5DS R.

    Roger

  • Roger Cicala

    Lisandra, they don’t suck too much for photography, but they suck a lot for lens testing.

  • Roger Cicala

    Steve, every point is the average of the 6 copies for that value: center, overall average corner average.

  • Roger Cicala

    Mike and William, except we wouldn’t know if the adapter deteriorated the performance or not. I’ve tried it before and each copy of the lens-camera combination has to be tried on a number of adapters to find one without tilt for that lens. And an adapter that works on lens A probably won’t on Lenses B, C, D, and E. Not the kind of thing I have time to do.

  • Kiril

    I wonder if the 36 vs 22 MP may be the reason to see difference between these lenses.

    Do you believe same test with A7 II would yeild less compelling result? or would using the upcomming 5DS R reverse the result in favour of Canon.

  • lisandra

    I know youll hate it, and me for also asking, but i also vote for a side by side on the a7r. Adapters suck, but we all use them!!!
    All kidding aside i think once on the a7r with a half decent adapter the canon will outresolve the sony.
    Ok now i reeeeeeaaally HAVE to know

  • Roger,

    First, let me thank you for the excellent data! Now, can you explain a little further what you mean by “average of 6 samples”? Were both cameras using f2.8? Are you talking center MTF, or a combination of edge, 1/2 out, and center? Or something else? Having this information would better enable me to compare Sony’s 55mm TESTED f1.8 MTF figures (which are excellent).

    I did find the 20′ verses macro most enlightening. I’ll bet it answers a really big question for many of us.

  • Weilli

    I recall that Roger has ever said that the precision of the adaptors would affect the results of the comparison, so I don’t know if it is the reason Roger doesn’t prefer to do that.

  • Weilli

    The resolution of Sony G90/2.8 in the 4 corners increased in the short focusing distance. Is it normal?

  • I agree with William Jaeger – a side by side on the same sensor would be very interesting..

  • Eric

    In the earlier announcements, Sony said that the 90 Macro would have a real mechanical focus ring enabled from the front clutch. Is it actually fly-by-wire then ?

  • Is it unreasonable to test the Canon 100mm on the Sony A7r with an adapter? That would be what most A7 users would want to know–whether to buy the Sony or the Canon (or the Nikonf or that matter)…since all will “work” on the Sony.
    Love your comments, always.

  • Mike

    Wish you would have adapted the 100L to the A7R. Then we’ll truely know if they are equal in performance or not

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