PetaPixel

Sony a7R: A Rising Tide Lifts All the Boats?

a7r_2

I have to admit I didn’t get too worked up when the Sony A7 and A7R were released. The last time I wrote about Sony it was how there were so few lenses for the NEX system years after introduction. So now we’re going to a system requiring a whole new lens mount. Sure the camera’s specs were interesting. But the idea of yet another camera body good mostly for shooting lenses on adapters wasn’t very exciting. So I planned to ignore it.

But my friends over at Imaging-Resource/SLRGear were waxing poetic when they talked about their testing of the A7. Then they started claiming that the lenses were really good, too, and sent me some rather shocking test results. Plus, I will admit when it arrived I kind of liked the look and feel of the camera. It’s a very small camera for a full-frame, but with a nice deep grip that felt good in my overly large hands. Sort of a retro appearance. So even though we were a bit backed up, Aaron and I decided to at least run some preliminary testing in our Imatest lab with the A7R.

Let me be clear — this isn’t an A7R review. Think of it more as a screening test to see if I was even interested in looking at it more seriously. For me, the lack of lenses with a newly released camera means going through several adapters and numerous lenses to see if I could make a reasonably useful kit. There are other options out there that would be a lot less trouble. So unless there was something about it to really impress me, I’d just skip it for now. If things were merely good, I wouldn’t be interested in looking further.

Results with the 35mm f/2.8 Sony Zeiss Lens

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We received a reasonable number of A7R cameras in, but only a few copies of the Zeiss 35mm f/2.8 FE lens and none of the 55mm f/1.8 Sony Zeiss Sonnar FE that Rob Murray reviewed with such spectacular results. But what we had was what we had, so we mounted the 35mm FE to the A7R and ran a set of tests. Then we ran them again because when I first saw the results I thought “we had that stopped down somehow, no way it did that at f/2.8″. But it did.

To put this in some perspective, I’m going to do something that’s not really OK: compare numbers between systems. I don’t want to play camera wars, and these aren’t extensive comparisons. But I did want to show you why my jaw dropped when I saw the A7R/35mm f/2.8 numbers.

In this case we’re comparing very closely matched systems: the Sony A7R and Nikon D800e are both 36 megapixel, no-AA filter cameras and we’re processing raw images that (theoretically) have no sharpening or manipulation applied. Even so, please take this with a grain of salt because, well, we’re comparing numbers between systems and that adds variables.

LR_a7r_1

Just in case you missed that, the Sony A7R with 35mm f/2.8 lens shot at f/2.8 outresolved the Nikon D800e with either the Nikon 35mm f/1.4G shot at f/4 or the Zeiss 50mm f/2 shot at f/5.6. Stopped down to f/4 to even the playing field, the Sony was clearly higher. In fact, the only lens-camera combinations we’ve seen with that kind of MTF50 is the Zeiss Otus 55mm mounted to a D800e.

That did leave me with a question, though. Is the lens that great? Or is the camera that great? Or is it the combination?

A Few More 35mm Focal Length Tests

Unfortunately, the only other FE mount lens we had was the little variable-aperture kit zoom. It may be a pretty good lens, but I don’t test variable aperture kit zooms when I’m trying to decide how good a camera is. You’ve got to draw the line somewhere.

The next thing I know Aaron has a tray full of adapters and a bunch of lenses. I pointed out that we don’t test lenses on adapters. I use adapters for taking pictures, they’re wonderful for that. But when you generate test numbers there’s always a bit of tilt that makes the overall test numbers lower than they should be. So I told him we absolutely weren’t going to test lenses on adapters.

He pointed out that center numbers would still be accurate. And that most people shooting an A7R are going to be using adapters so there were some real-world reasons for looking at them. I countered that we’d have to test a number of adapters with each lens to find the most accurate one and that would take hours. He replied that we had some wide-angle lenses that needed optical adjustment and that’s what we’d be doing if we weren’t testing. Game, set, and match to Aaron. There’s nothing I hate more than optical adjustments on wide-angle lenses.

To make things as accurate as possible, we tested a number of copies of each lens on a number of copies of brand-name adapters and took the best combination to present below. Again, let me emphasize that adapters that are perfectly fine for taking pictures (all of the ones we tried) aren’t usually fine for generating testing numbers. A bit of field tilt, for example, makes no difference in a 3-dimensional picture. (If the grass on the left side is in best focus a foot further away than the grass on the right side, it really makes no difference. If the focus on the test chart is a two inches different between the right side and the left side, the numbers on one side are awful.)

So what I’m showing you is the best lens-adapter-camera combinations we could find – but please realize that especially off-axis, the numbers we get from adapters are more variable than what we would see from a camera with native lenses mounted.

(As an aside, people always ask ‘what adapter brand is best’. It’s not a brand. We use mostly Voigtlander, Metabones, and MTF adapters, which we think have good quality overall. But with 4 interfaces — one lens, 2 adapter, one camera — there is inevitable variation. Adapters are like sausage. If you love sausage, you definitely do not want to know too much about how it is made. Same with adapters. The quality control isn’t what you hope it is.)

Canon 35mm f/2 IS

Since we had tested the Sony-Zeiss 35mm we thought we’d try a couple of other 35mm lenses. We started with the Canon 35mm f/2 IS lens – since we have extensive data testing this lens on Canon 5D II cameras we thought it would be interesting to see how it fared on a higher resolution sensor. We tried a few copies of the Metabones Mk III EF to NEX adapter and used the results from the best lens-adapter combination. The table below compares the results with this lens on an A7R and a 5D II.

LR_a7r_2

Obviously the A7R brings out some dramatic capabilities in the center of the 35mm f/2 IS lens that the 5D Mk II can’t show us. But the amazing performance doesn’t seem to carry out to the corners.

I think it’s important to look at what’s going on in the corners, so I’m going to go a bit geeky on you for a minute and show you actual Imatest printouts for the 35mm f/2 IS on the A7R. Below are the printouts at f/2 followed by f/4.

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LR_a7r_4

The top image, at f/2, demonstrates the little bit of tilt that is still present with our best lens-adapter match. The lower left corner is quite good, the upper right rather weak, and the other two corners in-between. This would be barely noticeable in a picture. But it makes the corner resolution numbers in testing quite questionable. Especially when you only see the average number like the table above.

In the second image, shot at f/4, the increased depth of field seems to make up for the tilt affecting the corners. But if you look carefully there is still a significant difference in the numbers for vertical and horizontal resolutions, particularly in the middle third of the lens. Astigmatism in the lens could cause something like this, too, but this is a lens we know doesn’t have much astigmatism.

So we can take away that the resolution in the center of the Canon lens adapted to the A7R is awesome. The corners are very good, but not spectacular. Why the difference between center and corners? Could be adapter. Could be sensor microsensors. Could be chromatic aberration. Could be something done during in-camera processing of raw images (these are raw shots, so no jpg conversion is taking place). In other words, I don’t know. But as with all unexpected results, we repeated the test and it was consistent.

Zeiss ZE 35mm f/2

As long as we were shooting at 35mm we thought we’d try the Zeiss 35mm f/2 on the A7R. Even wide open at f/2 the numbers were pretty spectacular. Again, in the table below we’ll compare the ZE 35mm f/2 on the Canon 5DII and the Sony A7R.

LR_a7r_5

The same pattern shows again; dramatic improvement in MTF50 in the center with the A7R compared to what we would see on a 5D II, but only a slight improvement in the corners. In this set the adapter gave us quite even corners, although, again, we did have some astigmatism off-axis that pulled the numbers down a bit.

At this point I did wonder if my choice of 35mm lenses might be part of the corner issues we were seeing. There are plenty of reports that wide-angle lenses have problems in the corners on cameras with short flange-to-sensor distances like the A7R. So I did want to try at least one set of longer lenses to see if the pattern continued.

A Set of 50mm Lenses

I chose a couple of 50mm lenses for the next test, mostly because I wanted to try at least one Leica lens. (Wide angle Leica lenses on the A7R are another topic entirely, and too big of a topic for me.) We had a Leica 50mm f/2 APO-Summicron ASPH handy, and thought the Zeiss ZE 50mm f/2 Makro Planar would make a nice comparison. We used a Voigtlander M to NEX adapter for the Leica and another Metabones Mk III for the ZE. (For both I’m using the best results of 4 adapters tried.)

LR_a7r_6

The most interesting comparison, here, I think is the Leica 50mm lens on the A7R and on its native Leica 240 camera. In the center, the A7R has much higher resolution than the Leica 240; it’s 36 megapixels versus 24, after all. But the corner numbers are more interesting. Here the Leica camera has resolution slightly higher than the A7R.

Given that the 50mm is not a retrofocus design, there shouldn’t be major corner issues with the A7R. Of course, there’s no way to rule out an effect from the adapter, although this was the best result with 4 adapters (all on the same lens, though, we only had one copy in stock).

Leica has said a lot about how their camera’s microlenses are angled in the edges and corners, maximizing the sensor’s performance with their own lenses. This is a very isolated finding of one lens on one camera, but it does seem to support that.

Conclusion

I’m not anti-adapter, by any means, and I wouldn’t hesitate to shoot a good lens on an adapter with the A7R. It’s important to bear in mind that numerical testing differences don’t always equate to significant picture differences. But there do seem to be some limitations.

If I were to make a quick summary:

  • The A7R delivers amazing resolution. At least as good as a Nikon D800e.
  • The two Sony-Zeiss prime lenses (the 35mm we tested, and the 55mm tested by SLRgear.com) are excellent. Hopefully other native-mount lenses will also be excellent.
  • Other-brand, standard-range (35mm and up) shot on a well-matched adapter give superb center resolution, better than you would get on the native mount camera, unless that camera is a D800e. Corner resolution is very good, although less than amazing.
  • Given past experience, and several early reports, shooting lenses wider than 35mm on an adapter is going to be a bit more challenging. I doubt we’ll be able to make too many generalizations. Rather each lens will have to be evaluated on the A7R to see how it performs.

My own conclusion is pretty simple: I need to spend some time investigating the A7R and its lenses. This is a small test group of lenses, but every single one resolved better in the center on the A7R than it did on any other camera. This is going to be attractive to a lot of people who have been lusting for a high-resolution sensor but didn’t have one available in their lens mount.

There are plenty of questions remaining, of course. The corner numbers may be just an artifact of testing on a flat, two-dimensional field. In real 3-dimensional photography things might be much better. This alone is going to require a lot of information by numerous testers before we get a good handle on it. It may go away when we get to slightly longer focal lengths. It may be something seen in only a few lenses and we just happened to pick those to test.

Even if the laboratory corner numbers reflect photography reality, though, remember the corners on the A7R are (except for the Leica lens) at least as good, if not somewhat better than the native camera mount. So the rising tide of the A7R sensor lifts all the boats in the center for sure. I’m still not certain about the corners.

So while I’m not ready to jump on the “this camera is going to change everything” bandwagon just yet, it certainly has the potential to change some things. Assuming some good third-party lenses become available in FE mount soon, and Sony continues to broaden the lens lineup with excellent glass instead of 10X variable aperture superzooms, it may change a whole lot of things.


About the author: Roger Cicala is the founder of LensRentals. This article was originally published here.


 
  • DA Nang

    sony…. the brand with good bodys but no lenses to match…..
    and in a few years sony will make no cameras and no TV´s anymore.. only sell insurance (what makes sony most money right now).

  • The_Nexus

    Having had the A7 for the last few weeks I am quite impressed. I did not opt for any of the native lenses (I will, however, get the 35mm at some point) but instead opted for a M-mount to E-mount adapter in order to use my Leica legacy glass. Unlike the posts from many A7r owners, I have yet to see any real big “issues” with the A7 using Leica glass. I have not noted any “smearing” or “coloured corners” but I also don’t pixel peep so if they are there, I am certainly not noticing them.

    There are many reasons to opt for the A7r (higher resolution, no AA filter0 but the A7 has an equal number of reasons which make it appealing to those with legacy glass – especially wide angle legacy glass.

    The attached photo is a snapshot SOOC jpg using Zeiss 21mm ZM f2.8

    In the end, when I was deciding between the two, I purchased the A7 and am perfectly happy with it :)

  • Alex Tardif

    Really? I suppose all of the CZ and G glass is below your standards? Say, starting at 16mm all the way through 400mm on A-mount, for instance? You’re clueless, bud.

  • Fed Up with weirdos like you

    I have NO FAITH in Sony what-so-ever.

  • Saaa

    yah that sonuy 200 f2 called playstation

  • http://byazrov.ru/ Byazrov.com

    Sony is a company that always abandons systems. It’s ok to buy Sony if you pretty rich and can afford to buy anything you want, but if you are planning to invest in the system than Sony should be definitely avoided as it has no respect for it’s customers.

  • tttulio

    I simply love the E-mount, I can us emy Leica, Zeiss/Contax-G, Contax-Yashica, Canon FD, Nikon and the Metabones Speed Booster.
    Who is complaining about lenses?

  • Paul S

    I never pay attention to these scientific tests – for me the proof is in he pudding which means going out and shooting. I used the same combo as In this “preview” and was left completely underwhelmed so much so that the intention I had of purchasing waned.

    Basically my gripes included the slow lens, poor AWB metering and colour rendition under mixed lighting, AF in accuracy (complete misses for no reason and numerous back focused shots) and average ISO performance. Hopefully Sony can iron out the bugs and this time offer a top family of fast lenses (which remains to be seen as the mount design may not lend to this). Time will tell.

  • gene

    It’s a very interesting test. However the same lenses were tested on a7r and the lower res 5d2 or leica. It would be interesting to see the same lens such as 35/1.4G or Zeiss 50/2 tested on both D800e and a7r, I think that would be a more meaningful comparison to see if there’s any actual performance difference.

  • Smarty

    Well, make sense if you’re pro who need continuous pro support. But Sony doesn’t have pro line for still camera, only video, and its pro support for video is.. professional. Consumer cameras are short lived, try perceive it as an electronic gadget rather than an investment. By the way, most Canikonians bought an entry level DSLR + a kit lens. It’s a one time buying.

    Owh, and you’re wrong. Sony doesn’t abandon things. It still uses that sucky MS Card when everybody else uses SD or CF.

  • kassim

    Make.Believe. Hehehehe…

  • Renato Murakami

    LOL, that is the one thing Sony should’ve abandoned a long time ago, really. It would be great for the brand. I imagine they still think consumers don’t know about their sketchy proprietary strategy of forcing these inferior overpriced SD clones no one wants to buy.

  • Joe Gunawan

    I actually found that the AWB is pretty darn good. I was at the Sony event in Tennessee and for the whole week that I was shooting the a7 and a7R, AWB performed well. ISO performance is really good, too.

    Fast lenses are needed, however. Good thing there are plenty of adapters available already.

    http://www.slrlounge.com/history-making-sony-a7-a7r-field-review

  • appliance5000

    You could try post processing for correcting color issues. I hear photoshop does a good job with digital files.

  • Paul S

    Yeah I can see why photographers that want to older MF glass are drawn to the system but if you want small fast primes then it’s a showstopper.

    Re AWB admittedly the mixed ambient conditions probably would have been hard for my Canon pro bodies too – but having said that my current mirrorless of choice, the Xpro1 would have had no problem.

  • Paul S

    Obviously those like myself who need fast small primes with AF ; )

  • Cinekpol

    A-mount lenses are not E-mount lenses. You need fidly adapter to use them.

  • Stu

    So we should fork out for the A7, a new adapter, a small fortunes worth of A-mount lenses, and then when they finally release E-mount versions of the lenses we can fork out again for the same focal lengths? The A7 is a great camera but it is a risky and pricey investment to adopt this as a primary system. The fact that the camera system is great does not guarantee that it will still be around in 10 years.

  • tomciviletti

    If the drop in A7r corner resolution is due to adaptor slop, then would not refocusing on the test target for each corner reveal this?

  • robin

    sorry sharpest is overrated… why people to comparing how sharp is it… there are many over aspect about the lens more worth to talk about

  • LOL

    Well, it is interesting, but 1365/1075 ≈ 1.27 and 1550/1135 ≈ 1.366: I am about center resolution of AACron 50.
    The means either there is something wrong with your testing procedure or something with Type 240′ sensor which decreases resolution: the difference should be about sqrt(36/24)=sqrt(1.5)≈1.22