Wednesday, February 8, 2012

Nikon D800 or D800E: Which one should you buy?


Well Nikon has thrown down the gauntlet. A full-frame 36 megapixel DSLR for under $3,100. I guess the megapixel race was definitely not over, not by a long shot. In addition, a special version, called the D800E, can be had for under $3,400, and it does away with the fine detail robbing effects of the usual anti-aliasing (low-pass) filter that is fitted in front of the majority of DSLR sensors. With the best Nikkor lenses and careful technique it will probably rival some medium format digital cameras, at least as far as fine detail rendition goes.

If anyone is worried that it will have abysmal high-ISO performance, well... I wouldn't be. Nikon's superb prosumer DSLR, the D7000, actually sports a slightly higher pixel density on its APS-C sized sensor and it has proven itself to have excellent dynamic range and very good high-ISO abilities. Sure, not quite up to the level of the 12 megapixel full-frame D700 or D3S, but excellent and very useable nonetheless. For any given size print, realize that the 36MP D800 will give a way tighter grain pattern than a 12MP camera, so what grain (noise) there is, will be far less obtrusive on prints from D800 images.

UPDATE: Come and see the D800 at our Fusion 2012 event! Nikon will have a booth and you'll be able to get some hands-on time with both the D800 and the D4.

This isn't going to be a full and detailed preview... there are already several excellent and detailed overviews available, one of the best being by Rob Galbraith (Announced: Nikon D800 with 36.15 million image pixel sensor) and a hands-on preview by dpreview.com (Just Posted: Nikon D800 hands-on preview). Instead, I am going to give you my thoughts on the BIG question: D800 or D800E? Yes indeed, I have received many inquiries already with people facing that decision and wondering which way to go. What I am hoping to do with this article, is steer people in the right direction so that they won't come back a month later, worried that they made the wrong decision!

What I hope to be able to do, some time soon, is personally test both bodies and do some side-by-side comparisons so that I am better able to advise people which camera might the best choice. For now, the following comments are based on my experience shooting with Hasselblad and Phase One digital backs, as well as the Leica M9, none of which have anti-aliasing filters (called AA from here on in), as well as a large number of DSLRs that do have AA filters.

What are the possible reason's why a D800E might not be the best choice? Isn't more detail always better? Well without going into the precise technical reason why these problems occur, I will list off the issues you potentially might encounter with a D800E: moiré (both colour and luminance) and maze artifacts, aliasing (stair-stepping or "jaggies") along sharp high-contrast edges, especially noticeable on edges at only a slight angle off a perfect vertical or horizontal, colour artifacts in areas of random fine detail like distant foliage ("Christmas tree light" artifacts), and lastly, a more subtle and hard to describe effect... differential lens sharpness. That last one will take some explaining, but first let me cover moiré and the other potential problems and demonstrate with an example...

Moiré example: click to enlarge and open in new window

 
The above image is a screen capture from Adobe Lighroom 4 beta, and shows a crop of a photo I took with a Leica M9, a camera without an AA filter. You will have to click on it to zoom in and see clearly but when you do, you will see the very obvious colour moiré (diagonal colour stripes) caused by sharp horizontal window blinds on the left side image. Some people are already arguing that moiré won't be an issue with the D800E since Lightroom 4 will have an anti-moiré brush. Well, on the right side, you will see the results of Lightroom 4's anti-moiré brush: sure the colour artifacting is gone, but you still see very obvious and distracting luminance moiré which is substantially harder to get rid of. While it is not impossible to remove, it is nevertheless extremely tedious to do so, not something you'd want to deal with on a regular basis. Of course since this is only Lightroom 4 beta, there is a chance that the final version could have more sophisticated processing, however I don't believe one can count on that. Also, one has to be careful with the anti-moiré brush: you can see where my quick application has desaturated and bled the colour from the letters in the Sutton realty sign, something easy to fix in this case, but I left it in to show what the anti-moiré brush does to other normal colour detail - it bleeds and desaturates it.

Secondly, the above image demonstrates the line stair-stepping I mentioned. If you'll look at the edges of the windows, you'll see they are not smooth diagonals, rather they are presented as a series of steps. Lastly, on the lower set of windows, you'll see some strange "maze-artifacts", caused by Lightroom's Bayer-sensor demosaic algorithms as they are confused by the fine, closely spaced and regular detail. These maze artifacts are also something that will likely crop up more often with a D800E than a regular D800, and virtually every raw converter suffers from such artifacts in some situations.

The good news is, on the other hand, that you can see in the above example that the fine branches of the tree are actually rendered quite well, with no significant issues at all.

The last thing I will mention on that topic, is that even cameras that do have AA filters will sometimes suffer from those effects, especially if you use a lens that is particularly sharp and renders images with high acutance, so even a regular D800 will probably display some of these problems occasionally. However the severity will likely be substantially reduced and such problems will occur more rarely.

As far as colour speckle artifacts in areas of fine random detail (Christmas tree light artifacts), I do believe that modern raw converters handle this effect quite well and I really doubt that you will ever come across it. Back in 2004, when I tested the Kodak DCS Pro SLR/n, another camera that didn't have an AA filter, I had horrendous problems with all of the above issues, including Christmas light artifacts seen in fine foliage details, but nowadays my gut feeling is that you won't have any problems in that respect, even with the D800E.

Now, let me try and explain the "differential lens sharpness" issue I mentioned. You could glom this together with various other things as well, since what I am describing is the obvious differences you'll see between areas of the image that are critically sharp, and areas that are slightly off, when shot with a camera that does not have an AA filter.

Most lenses have some degree of sharpness falloff near the edges, or especially the corners, more when used wide open and improving gradually as you stop the aperture down. With the best telephoto lenses, there is sometimes no falloff at all and you may get near-perfectly sharp images from corner to corner even wide open. Other lenses, especially ultra-wides, may suffer quite dramatically as far as corner sharpness goes and require substantial stopping down before images start looking evenly sharp, corner to corner. However the sharper and higher resolution the camera, the more obvious any lens issues will become. When you have the very slight blurring effect of an AA filter, minor differences in sharpness will become harder to see, and indeed with the sophisticated sharpening algorithms that modern raw converters use, often such slight differences may be "evened out" in post-processing. However, you have to be very careful when sharpening images taken without an AA filter, since too much sharpening can lead to an image that looks too "crunchy", or over-sharpened. Indeed, my Leica M9 example is perhaps slightly over-sharpened, but all of the problems can still be seen even if sharpening is turned right off in Lightroom. If you need to bring some corner or edge sharpness back from an image whose center is already tack sharp, you may need to resort to somewhat tedious masking and differential sharpening in Lightroom or Photoshop to even things out, so that the already crisp parts of the image don't become too sharp.

The revealing nature of images shot without an AA filter will also more clearly show focus errors, motion blur, camera shake and even image-stabilizer glitches. Anything that slightly softens detail in an image will stick out like a proverbial sore thumb on a camera without an AA filter, once you zoom in and pixel peep.

That said, some of what I am warning about is indeed only going to be visible when you pixel-peep, when you zoom into the image at 100% and critically look at the finest details. In reality, the differential sharpness issue I mention won't necessarily show up in prints, unless you print really big, but of course those buying their brand-new 36MP D800E cameras will most certainly be zooming and looking at their shots very closely! Just be warned that such pixel-peeping will quickly reveal the quality (or lack thereof) of your lenses and of your shooting technique! On the other hand, moiré can destroy an image, even on much smaller sized prints.

So which one should you buy... a D800, or a D800E?

In a nutshell, as far as moiré, stair-stepping and maze artifacts go, if you are purely a landscape photographer, one that shoots natural objects than do not contain any regular repeating patterns, then the D800E might be the best choice since you will probably only rarely (if ever) encounter any of these problems. One exception might be if you are a wildlife photographer since bird feathers do have a very regular, sharp and repeating pattern and the D800E might indeed have problems there. I can also imagine a wheat field off in the distance, where the straight parallel stalks might cause an issue but again, other than feathers, problems like that will likely be few and far between.

On the other hand, if you are portrait, wedding or product photographer that shoots clothing and fabrics, you should very probably stay away from the D800E and buy the regular D800! The same may go for architectural photographers. With inside shots, you may have furniture fabrics to worry about and with outside photos you might have patterns from windows, blinds or bricks off in the distance.

What you really need to think about, is how often do you shoot items with regular repeating patterns and if so, are you able to reframe the shot and get farther away, or move closer in in order to minimize the moiré if it appears? Yes, by changing the size of the image on the camera's sensor (smaller by moving away, larger by getting closer to your subject) you can sometime eliminate moiré if you notice it as it occurs. The key is, of course, noticing the moiré when it happens so you can do something about it, right then and there! However if you are photographing a scene with a lot of depth (for example, think of a fabric couch, shot with a wide angle lens for dramatic perspective) then some part of the subject might always be at just the right magnification to cause moiré, so there might be nothing you can effectively do about it.

Basically, what I am saying is that for the vast majority of photographers, my gut feeling is that the regular D800 is probably going to be the right choice. Even with an AA filter, you are going to be getting a camera with spectacular resolution! However if you are a landscape shooter, or someone who is very methodical and careful in their shooting technique, who is willing to deal with moiré and other issues when they occur, well then you might indeed see a small benefit in resolution by choosing the D800E... if your lenses and technique are up to the task! If you have older lenses that are not up to the resolving power of the D800E, then you will also be less likely to encounter these image artifacts since the lens will be acting as the camera's AA filter! Of course in that case, you would also not be seeing the extra resolving power that the D800E is capable of either.

This choice is going to be a tough decision for some people, and hopefully I have shed some light on some of the possible issues. If you are having a hard time deciding, by all means give me a call at Beau and I'll try to help out! Lastly, keep in mind that you could almost buy both the D800 and the D800E for the price of a new D4. (Okay, just kidding...)

2 comments:

  1. What about the photographer who's going to use the camera for video shooting? 800 or 800e?

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    1. I would say it's too early to tell for sure if the D800E might be worse for video. It really depends on the precise down-sampling algorithms that Nikon is using. If in doubt, I'd say that the regular D800 would be the safer bet for video. You'll certainly never see any subtle loss of resolution that the anti-aliasing filter will create after the camera downsizes to 1080p, and if you do get bad moiré at full resolution in a certain situation, I suspect it might indeed show up on video footage as well.

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