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“D” resolution tests

Published March 24, 2012

It’s been kind of an exciting couple of weeks, with 3 major new SLRs released and a couple of more on the way. There are plenty of people out there who are doing in-depth reviews, touting the greatness of the new cameras, and trashing them online without having touched one (My favorite so far is the guy who, after looking at online jpgs, stated it was obvious that the 5D Mk III and D800 weren’t a bit better than his T2i, so he wouldn’t be upgrading). I don’t have much to say regarding image noise, ergonomics, autofocus accuracy, image processing, etc. There are plenty of people doing that more thoroughly and accurately than I could.

But there was one question that was really eating my lunch and I was in a position to take a look at it: just how much better would the Nikon D800, with that gazillion megapixels, really resolve? Would it be 3 times better than a D700, and 50% better than a Canon 5D Mk III, which the pixel count would suggest? Would the lenses we have really be able to take advantage of that resolution? I wasn’t sure.

So when we got a bunch of Canon 5D Mk III’s and a few Nikon D800s in last week and I was able to divert a few over to our Imatest lab for a few hours. There wasn’t enough time to do exhaustive testing (generally the cameras arrived at 10 a.m. and had to be in packing to ship out by 3 p.m.) but I was able to get enough done to make some preliminary observations.

Comparing Camera Resolution

I arbitrarily chose two lenses to do the camera comparisons: the Zeiss 100 f/2 Makro Planar and Zeiss 25mm f/2.0. I chose Zeiss lenses because it let us put identical lenses in front of both Canon and Nikon cameras. These two particular lenses because both are exceptionally high resolution lenses and I wanted to be able to test at two different focusing distances, since that could make some difference. The copies used for this test had previously been tested and were known to be excellent and free of optical issues.

We tested each on D800, 5D Mk II, and 5D Mk III cameras (and one run on a D700 just for comparison). Otherwise things were kept as equal as we could make them: lighting and setups weren’t changed, etc. Time constraints prevented doing what I would have loved to do: testing a half-dozen copies of each lens on a half dozen copies of each body. But this should be fairly accurate.

I should note that we initially ran the Canon files through DPP to convert the raw images, since Imatest can’t directly convert the 5D Mk III files yet, but the results we got showed DPP was obviously doing some manipulation to the files as it converted them, making the results invalid for comparison since we test on unsharpened raw images. We then used Adobe’s DNG converter which handled the files with no problems and didn’t manipulate them at all, so we used RAW-to-DNG conversions for all the cameras to make sure things were equal.

The Zeiss 100 results first. The Vertical axis is the peak (center) MTF 50 (in line pairs / image height), the Horizontal axis aperture, and the cameras identified in the legend. The D700 and 5D Mk II results agree exactly with what we’ve seen testing these combinations for several months.

Results for Zeiss 100mm f/2. Makro Planar

Results with the Zeiss 25mm f/2.0 lens were very similar. I left off the D700 after the first test. I saw no sense beating a dead horse and, as I mentioned, time was short.

Results for Zeiss 25mm

The results certainly weren’t surprising: I expected the 5D III to be a bit better than the II and it was. I expected the D800 to be better than any 35mm camera we’d tested, and it was. Previous, only the Leica M9, with its no-AA-filter, CCD-sensor, using the $6,000 Leica 50mm f/1.4 Summilux lens and gets up in this range among 35mm cameras. For the couple of people, though, that seem to think the D800 is a medium format camera in 35mm clothing, I would point out that a Hasselblad H4D-50 with kit lens tests out at about 1,600 lp/ih, so no, we’re not quite there yet.

At Higher ISO

The above results are taken at ISO 200 which should theoretically giving best, or near-best, performance for each camera. I was curious how the D800’s resolution would hold up at higher ISOs so I repeated the ZF 25mm on D800 series at ISO 400 (where I do most of my shooting – it’s my test after all) and also at ISO 1600 and ISO 3200.

Again, this is done from raw images with no (as best I can determine) post image sharpening, although you can never be sure what is happening in-camera. But at any rate, there really is an amazingly small amount of resolution fall off at reasonably high ISOs. I was really surprised at this, especially at how well 3200 compared to 1600. Obviously I should have gone further, and need to do the same comparisons for the 5DIII, which I should get to next week.

What About Lenses?

Ah, now that is the question. At least it’s the question now. Lloyd Chambers had already mad some good suggestions for Zeiss and Nikon lenses that should be able to handle the D800’s resolution based on his experience. I’m not sure I agree with all of them, but it’s certainly the best starting list. I plan on testing each lens on the D800 and getting a list of our own together, but I was able to get some of the usual players tested before the last D800 left the shop.

The first graph plots peak (center) MTF 50 comparing the ZF 25, Nikon 24 f/1.4G, Nikon 14-24 f/2.8, and Nikon 70-200 f2.8 VR II. There’s a pretty significant difference between the primes and zooms at f/2.8. It’s not surprising, since the zooms are wide open there, but I thought the point was worth making: if you want best resolution with the D800, shooting at f/4 or f/5.6 is going to be necessary with most lenses.

Center only MTF 50

The second plots average resolution of the center, halfway to the corners, and corner MTF 50.  It becomes apparent that center resolution doesn’t mean corner resolution: the 70-200 VR II does much better in the corners than the 24 f/1.4. The Zeiss 25mm does superbly well, but I should point out that this lens seems to do it’s best work at close and medium distances (like where it is when we do Imatesting) and may not be as good at infinity.

Obviously, there are a lot more lenses that we’ll need to test just to make recommendations based on resolution. The only message I think to take away right now is that the D800 is playing up in the range of maximum resolution of even the best lenses. Putting anything less in front of it is going to limit the camera.

Conclusion:

For the fanboys who don’t like the results: This concludes our test of the Emergency Resolution Testing Service. This was only a test.  If this had been an actual Fanboy emergency you would have been instructed where to tune in your area for official Fanboy disinformation and complete manufacturer sponsored reviews.

For everyone else, there’s no question the D800 can actually get those pixels to show up in the final product (assuming your final product is a big print – they’re going to be wasted posting on your Facebook page). But you’d better have some really good glass in front of it if you want to demonstrate all of that resolution.

In the real world, highest possible resolution is nice to know about and talk about, but usually not of critical importance compared to other factors. You’ll be able to make superb images with any decent lens for an 8 X 10 or even 11 X 16 print. But if you’re getting the camera because of the resolution, it makes sense to know which lenses will allow all of that resolution to be utilized. Just in case you get that job that needs billboard sized prints.

 

Roger Cicala

Lensrentals.com

March, 2012

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.

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  • Hey!
    Thanks for the testing.
    Trying to figure out is the D800 will give any advantages in macro (real one 🙂 ) where effective working aperture is 30 and smaller. Is any tests showing the graph until f22 (by settings)?

    Thanks again!

  • Dave Sucsy

    Hey Roger,
    Thanks for your great business and your great blogs and testing info. Also your sense of humor. We might as well have fun while doing our work!
    I’m annoyed with both Nikon and Canon. The D800’s versatility of the file size (croppability, down-res ability, and better dark value manipulability) may cause me big trouble in having to switch from Canon to Nikon. And Nikon is really holding my nose to the grindstone in causing me to have to be more picky than ever with my technique. All I do is real shooting for a living.
    Thanks again for this objective performance report.

  • Bryan Willman

    Do you have the same data for an M9, and could you overlay it with the D800?

    As an M9 user, and geek, I’ve always been a little perplexed by the high ratio of “picture success” to “technical specs” – and just think “it’s the lenses” and shrug.

    Also – you test suggested that for the D800 and the 5dM3, resolution is lens limited wide open, but becomes sensor limited by about f/4 for these particular lenses. I wonder if we’re coming to an age when 1st line cameras will be limited lenses rather than sensors. (And both will be swamped by technique.)

  • Information much appreciated. Wonder where the Pentax 645D and say, the 120 macro would fit in the graphs.

  • Jerry Russell

    Daniel: Thank you! DXO says the 300 2.8 IS II gets 61 lp/mm on the 7D. Looking through more of the DXO lens data, I agree there’s something odd going on. They think the 70-300L is not any sharper than the old 70-300 IS, for example.

  • Daniel Browning

    Ah, thank you for the explanation!

  • *Daniel Browning wrote:

    > I’m not sure how much different that is from a diffraction PSF (probably just models the central spot and no rings), but I vaguely recall someone saying they were similar enough to be used for the same purpose.

    This depends on what aperture you are referring to. At larger apertures (say, f/2.8 to f/5) the MTF curve of diffraction looks very much like a straight line (see my earlier post for a link with examples). In other words, it decays much more slowly with increasing frequency, compared to the Gaussian approximation of the sensor AA filter.

    The RL deconvolution implementation in RawTherapee is hard-coded to use assume a Gaussian PSF. This implies that for a small radius (standard deviation) setting of about 0.57 in RT’s RL sharpening, you can “undo” the Gaussian blur of the AA filter, but diffraction will remain. If you use a larger radius, you will sharpen more, effectively reducing the effects of diffraction, but also introducing significant distortion below Nyquist.

  • Thanks for the tests can’t wait to see which lens are fit for this big boy

  • Rob

    Brian Potter – the 24pc-e is sadly not fully compatible with the D800! the popup flash gets in the way of movements.

    Also it looks like the live view 100% zoom is acting a bit weird too, which isnt great for tilt shift use…

  • Daniel Browning

    * Jerry Russel wrote:
    > How do you do your sharpening?

    Usually just Lightroom.

    > Do you have an application that does “diffraction deconvolution”?

    I don’t shoot in diffraction-limited circumstances very often (I’m more of an f/2.8 kind of guy), but I’m still looking into it. My front runner is Raw Therapee, which uses the Richardson Lucy algorithm.

    That said, I may have used a similar deconvolution in this case. IIRC, Eric Chan (one of the software engineers behind ACR/Lightroom) said that the sharpening slider moves between USM and deconvolution sharpening with a gaussian PSF. I’m not sure how much different that is from a diffraction PSF (probably just models the central spot and no rings), but I vaguely recall someone saying they were similar enough to be used for the same purpose. Somewhere in the middle (which is where my setting was for this shot), the slider uses a mix of both.

    > Your sample looks great.

    Thanks. For that I one I used 45/1.0/100 in LR4.

    > I think I see the “moire” — you’re referring to the broad, dark banding, right?

    Yes.

    > Wouldn’t you expect to see at least some of that type of artifact, unless you filter hard at half the nyquist rate?

    Yes, but my feeling is that I’m seeing it more and easier with the D800 than the 5D2.

    > I’m not sure I understand why you would expect the results of this test to be different at MTF30 or MTF15.

    Because my understanding is that most lenses have long-tail MTF curves. Their MTF drops pretty precipitously for the first 30 lp/mm or so, but then it holds on to the last bit of MTF for a long time. But perhaps I’m mistaken.

    > DXOmark tests lenses at MTF20, and if you look at their results for the Canon 85 1.8 (sharpest Canon lens they’ve tested) they get 67 lp/mm on the 1ds3 (pixel pitch 6.4 um) and 80 lp/mm on the 7D (pixel pitch 4.3 um). That is, a 48% increase in linear pixel density on the 7D (2x the data per square millimeter of sensor area) buys a 20% improvement in resolution at MTF20.

    I must be mistaken, then. I thought that hitting MTF-15 at frequencies nearing the Nyquist of a 4.3 micron pixel wasn’t really that exceptional, but perhaps it is. I’m glad that my $90 macro is one of them. It’s hard for me to find the data you used on dxomark, their site has been very slow lately.

    Can you check their data for the 300mm f/2.8 II? That thing is almost diffraction limited, and even with a 2X TC turns in nearly flawless resolution. But if DxOMark thinks it’s no better than the 85mm f/1.8, I think there must be something else going on, because I’m pretty certain the 300mm can give the full expected return of 4.3 micron pixels.

    > This also highlights the fact that it’s just as important to use high resolution lenses to get the most out of any recent crop camera, as it is to use great lenses on a D800.

    Agreed.

  • John Jovic

    Nice work!

    JJ

  • Jerry Russell

    This may be a thread-jack, but I hope Roger will open things up for a more general D800 vs. 5diii discussion. I can’t think of anyone better qualified to make the comparison.

    I’m moving up from crop to full frame, so several of my old lenses are irrelevant anyhow, and it will never be easier for me to switch brands.

    The D800 definitely has the better sensor. Judging from the sample photos around the web, I’d say it’s at least a half-stop better at high ISO than the 5diii, and it has that incredible 14.4 ev of dynamic range according to DXOmark.

    But, the 5diii sensor is a big improvement over the 5dii. I didn’t understand this until I looked very closely at the RAW files. My guess is the difference between the 5dii and 5diii sensors won’t show in the DXOmark scores — but it looks to me like they’ve made a big reduction in the color blotchiness and banding of their pattern noise. The actual usability of the images might be one or even two stops better than the 5dii at high ISO. And, using reasonable noise reduction, I’d say that it’s now possible to pull 3 or 4 stops of shadow boost in LR at low ISO, whereas the 5dii and 7d could only do a stop or two — and my 50D looks bad in the shadows even at ISO 100 with no shadow boost at all.

    I think maybe I can live with the Canon’s 22 megapixels of resolution, and 3 or 4 ev of usable dynamic range headroom. The Nikon sensor is better, but maybe not so much better that it would make much difference for real-world photographic conditions.

    Canon has some advantages too — better customer service and parts availability, for one thing. Better lenses, and a better selection of lenses. Their autofocus is certainly more complex, though I don’t know whether that means it’s better. Anything else?

  • Jerry Russell

    Regarding Daniel Browning’s remarks:

    How do you do your sharpening? Do you have an application that does “diffraction deconvolution”? Your sample looks great.

    I think I see the “moire” — you’re referring to the broad, dark banding, right? It appears to be a “beat” pattern between the texture of the cloth, and the pixel spacing. Wouldn’t you expect to see at least some of that type of artifact, unless you filter hard at half the nyquist rate?

    I’m not sure I understand why you would expect the results of this test to be different at MTF30 or MTF15. DXOmark tests lenses at MTF20, and if you look at their results for the Canon 85 1.8 (sharpest Canon lens they’ve tested) they get 67 lp/mm on the 1ds3 (pixel pitch 6.4 um) and 80 lp/mm on the 7D (pixel pitch 4.3 um). That is, a 48% increase in linear pixel density on the 7D (2x the data per square millimeter of sensor area) buys a 20% improvement in resolution at MTF20.

    This also highlights the fact that it’s just as important to use high resolution lenses to get the most out of any recent crop camera, as it is to use great lenses on a D800. For that matter, a 5Dii/iii or an old 40D is almost as demanding.

  • Daniel Browning

    * Jack wrote:
    > Do note that the D800 files are more than 2x the size
    > of the 5D3?s. What a load of extra bytes of data for a
    > 15% increase in resolution.

    There may be a few things you’re not considering. First, you are comparing a one-dimensional unit of measure with a two-dimensional one — it makes no sense. It’s like saying “this 13-inch box takes up more than 2x the volume of the 10-inch box. What a load of extra volume for only a 3-inch increase.”

    Second, the 15% increase that Roger measured only applies to you if you don’t use any sharpening and MTF-50 happens to coincide with your personal idea of a resolution limit. Neither of those apply to me or a number of other photographers, which is why I and many others are reporting success achieving the maximum theoretically-possible increase in linear resolution (27%).

    You can already find dozens of examples around the web of pixel-sharp D800 shots. For example, this 100% crop from my D800 is sufficiently sharp for me: http://thebrownings.name/images/2012/2012-03-D800/res-example-crop.jpg — and that’s softened very heavily by diffraction at f/11 (Roger stopped at f/8 because diffraction was getting so bad).

    Third, I consider Nikon’s file format options to be significantly more compact than Canon’s. The so-called “lossy” (or non-reversible) NEF compression is excellent for reducing file size and is not “lossy” in any meaningful way. You can also select 12 bits for an even more reasonable file size without sacrificing anything compared to Canon. (I explained in another of Roger’s blog posts why Canon’s 14 bit files really have no more than 12 bits of actual useful data.)

  • Jack

    Great article!

    Do note that the D800 files are more than 2x the size of the 5D3’s. What a load of extra bytes of data for a 15% increase in resolution.

    And… this resolution increase is subjected to lens quality, camera shake, ISO and what nots.

  • Roger Cicala

    Paul,

    We ran M9s with all the various 50mm lenses (we think the 50mm f/1.4 Summilux is possibly their sharpest) and it was clearly better than the 5D II / III and D3x bodies, but not as good as the D800. Look at our “great 50mm shootout” article.

  • PaulB

    I would like to see the Leica M9 added to the above charts using comparable lenses for the M-mount; since it was mentioned. I suspect the results will be fairly close the the Canon results, but the lack of an AA filter should give it a slight edge.

    PaulB

  • Roger Cicala

    Alex,

    I would expect it to be right around the 5Ds, assuming we got one of the better lenses on it.

  • Roger,
    Nice article and analysis! I look forward to more tests and now will have to increase my purchasing and rental budgets accordingly! Great mention to referencing Lloyd’s site as it is a wealth of data to help raise the bar in maximizing our new found equipment and making fine prints! I bought a new D800 and now I need not only a new computer, new tripod, new printer, new memory cards, but also lots of awesome glass to squeeze the most pixels out of it! It never ends 🙂 The camera is cheap in comparison to those extras. I guess I will have to rent more lenses!
    Keep shootin’
    John

  • Roger –

    Any thoughts about where the Sony A900 would have placed on this test?

  • I think the guy with the T2i was exactly right… providing you limit your photos to computer screens and don’t print large pictures, and probably 90% of us do.

  • AJ

    Dear Roger,
    Thank you for reporting you test reports. Very informative.
    However the tests cover the ‘best camera, best lens’ scenario.
    It would be nice if you were to compare the D800 vs. the D700 with ‘less than ideal’ glass for comparison purposes as you mention that better quality lenses are required to get the best performance out of the D800.
    Thus buying a D800 also means having stock of, or purchasing, better lenses to go with it.
    one way or another, the ‘total cost of ownership’ is high.
    For those that have ‘good’ affordable’ lenses perhaps the change to a D800 is not waranted if the results are not going to be significantly different from the D700 with ‘good afordable’ lenses.
    Just a thought.

    Kind regards,
    AJ

  • Thanks for the early results, Roger!

    The peak MTF50 for the Zeiss lens looks slightly low. If I understand your chart, you report MTF50 in line pairs per picture height. For the D800, this would mean about 1225 line pairs over 4912 lines, or about 0.25 cycles per pixel. This value is very high, but lower than I expected.

    For example, using a Sigma 17-50 mm f/2.8 at 35 mm f/5 on a Nikon D40, I measure almost 0.3 cycles per pixel in the green channel. Swapping the D40 with a D7000, I measure about 0.29 cycles per pixel (meaning mostly that either the lens is limiting resolution slightly, or I have not achieved perfect focus). See http://mtfmapper.blogspot.com/2012/03/measuring-centre-sharpness-of-my-sigma.html for more details.

    Since the D7000’s pixel pitch is ever-so-slightly smaller than the D800, I would expect similar results if the AA filter blurs to the same degree.

    So now I have to wonder: did Nikon mount a slightly softer AA filter on the D800 (compared to D7000) in anticipation of the D800E, or are we simply looking at a (very minor) measurement error?

    Based on my measurements, and assuming similar AA strength on the D800 and D7000, I would expect peak MTF50 values of around 1425 line pairs per picture height. Of course, that level of sharpness will only be seen in the real world by pure luck 🙂

  • I look forward to seeing the results of more Nikon lenses on the D800. I am sure there will be some surprises in the coming weeks as more combinations are explored.

    I am also very curious about what would result if you used an adapter and some respectable medium format glass on the D800? Could something like this be used to expand the depth of field before diffraction sets in? For a landscape photographer…

  • Roger Cicala

    Tim,

    I expect the fall off we’re seeing at f/8 is largely diffraction related. I could be wrong, there might be other explanations, but I think diffraction is the fast horse. We would be expecting to see it by that point, or certainly by f/11.

  • Don’t forget who developed and manufactured the D800 sensor before you make a declaration of who’s king of the castle…

  • Another great post, Roger! I don’t know if there is a more interesting photography-related blog on the net.

    When you get the opportunity to do more testing I would be interested to see to what extend diffraction actually affects resolution in the real world. Given the apertures at which you tested, I would assume that the fall off in resolution reflects diminishing lens performance rather than the effects of diffraction. This leads me to wonder if diffraction really has much of a practical effect or if it is masked by reduced lens performance at smaller apertures.

  • Great post roger, as always informative! Love reading the comparisons and research, but some of these other comments leave me speechless. Almost gone are the days when actual photographers use these wonderful tools. Put down the calculators, and pick up a camera, and find a way to make it work for you 🙂

  • Karl Riek

    Hey Roger,

    Nice article, even if my eyes did glaze over. However, I love the zings directed at fanboys. Who cares what equipment is used! The only thing that truly matters is the results that are produced. Hell, someone could be shooting with a Kodak Brownie for all I care! 🙂

    Anyway, I would expect the 5D Mark III to have better numbers against the Mark II (and the 5D classic). I find it interesting Canon packed more pixels in the 5D Mark III than the new Mark X (which I would really love to buy!).

    Thanks for taking the time to create the test and write the blog.

    Best regards,

    Karl

  • Daniel Browning

    Great test!

    MTF50 is definitely a useful metric, and it’s definitely the most appropriate measure for photographers that don’t use sharpening, or for circumstances where sharpening is avoided due to noise.

    But there are a lot of photographers who do use sharpening, and for them MTF-50 is not a significant resolution barrier. Especially in the case where the drop in MTF can be modeled by known point spread functions, such as diffraction. Depending on one’s taste, MTF 0.3 or even 0.15 may be usable with appropriate sharpening (or diffraction deconvolution, if that happens to be the cause of the MTF drop). I think a plot of the MTF-15 would show a much more distinct difference between pixel counts, even for circumstances that are significantly poorer than the ones used in this resolution test (such as cheaper lenses and narrower f-numbers).

    For example, two days ago I shot a 70-person group photo with my new D800. I used a cheap 55mm f/2.8 micro nikkor ($90, used) at f/11. But the results were so sharp that there was still several instances of moire (despite softening from both the AA filter and diffraction itself), and after sharpening, the contrast at the highest levels of detail is great. Here is an example of the moire: http://thebrownings.name/images/2012/2012-03-D800/D800-moire-example.png

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