I think people are creating a bit of a warped idea of what "high resolution" DSLR photography is with the advent of the D800 and its 36.3mp sensor. The resolutions we have been getting out of digital cameras these days is really incredible, and the fact that quality has not only remained high, but keeps improving as resolution grows, begs a tip of the hat to the likes of Canon and Nikon both. I think the fact that the resolutions we have today are more than adequate for anything but the most demanding
professional cases, except for one, can be proven as well.
For one, Canon DOES care about high resolution photographers. When they released the 5D II @ 21.1mp, it was the highest resolution digital camera on the planet, by about a 72% margin (over the 10-12mp cameras that were available at the time.) Its been selling like hotcakes ever since it was released, and there still seem to be more than a few people who would prefer to buy a 5D II at $2000 than a 5D III at $3500. There is also plenty of time left in this year, and there are still outstanding rumors that a 40mp+ monster is in the works by Canon (potentially the competition for the D800, probably released by Photokina.) Over the last four years, plenty of photographers, professional and otherwise, have been taking 21.1mp photos, as well as photos of much lower resolutions, and blowing them up to huge multi-foot dimensions with stunning quality. Personally, I've taken the meager 12.2mp images of my old 450D, and blown them up to 60x40" size (about 5x3.3 feet) as part of some experimentations on digital photography, printing, resolution, and quality in rough comparison to film (and outside of 300dpi drum scans of 4x5 transparencies, digital outperforms 35mm film and many medium format films without question.) From a quality and enlargement standpoint, 36mp is not a necessity
, and unless you intend to print at a high print resolution at immense dimensions, will probably never actually be a necessity (not in the general sense.)
Landscape photographers (such as myself, I do landscapes, birds, and wildlife) tend to prefer their whole photograph, and the only time cropping really comes into play is when you accidentally include something you did not want (i.e. due to a less than 100% CF VF) or when you need to level the horizon. Digital enlargements begin to break down when you blow things up beyond about 2-3 times larger than their original size, so if you print at 10 feet, you might indeed actually need more resolution. If you normally print on 17x22"/A2 size or smaller, 21.1mp is enough for a native resolution print with standard fine art border. If you normally print 34x44"/A0 size, 21.1mp is plenty for enlarging without any visible loss in detail at an appropriate viewing distance (even if you did print at 300ppi.) If your primary mode of display for your photography is via the web, then a simple 8mp camera is more than you would ever need, since you need to downscale most of the time to shrink the huge native resolution of a modern DSLR photo to a size that can be reasonably viewed on the average computer screen.
Personally, I like 24x36 and 34x44 sizes for my landscape photos hung on my walls at home (and I like John Fielder's work hung on the walls at my workplace at similar sizes.) At those dimensions you're already at multi-foot size. Unless you have some extremely large walls to hang your work on or fancy and unique gallery representations for your work that would actually warrant a 60x40 size print or larger (and even then, you can often print at lower resolution, so your still not enlarging more than 3x in such a case), there is no actual need
for higher resolution from a print standpoint.
There is one case that I think can legitimately demonstrate a need for more resolution. Personally, I would prefer more resolution for this very thing, however it comes with a couple caveats, although those caveats are mitigated more and more with improvements to DSLR technology. The real legitimate case for more resolution is CROPPING POWER.
Its a hell of a lot cheaper to buy a $3500 camera, or for that matter even a $7000 camera, if it has enough resolution to allow you to slap on a 400mm lens and capture photos of distant subjects, then crop to compose and fill the frame properly. Without cropping power, you might very well need a $13,000 super telephoto lens to capture the same photo. Even with cropping power, your not going to match the same level of IQ as you could get from that $13,000 lens...but its thirteen grand
! For that much money, you could get 3 5D III's and the brand new 24-70 L, or two 1D X's! You could also spend $3500, bank the $9500 difference (earn some interest on it), and buy some less expensive lenses, or even buy the 1D X as well as the 5D III, and still have money left over. CROPPING POWER
...its the real value of higher resolution that I can see, at least for those who shoot distant subjects, want more magnification, but don't have ten grand or more to drop on a supertelephoto. But its largely useless for landscape photography, and I would presume for wedding, studio, still life, street, and most other kinds of photography as well. Unless your printing at GARGANTUAN
size...and even then...from a native print size standpoint, compare the 5D II and III to the D800 (300ppi):
Given these differences, if your printing at 34x44, 50x40, 60x40, the native image resolution of the camera really doesn't matter, the differences are negligible when enlarging so much. You get far greater benefit from improvements to dynamic range, ISO, and reductions to noise than you really get from increased resolution.
Assuming you do get a high MP camera for its cropping power, you have to deal with the drawbacks. No matter how much spatial resolution your camera has, there is really no substitute for optical magnification power. If you really need maximum quality and the only way to get it is with a 600mm lens, then all the cropping power in the world isn't going to help you. From a physics standpoint, smaller pixels mean the random nature of photons will increase noise over larger pixels. There are also other electrical and physical limitations with smaller pixels that limit how much IQ you can extract from them.
So, unless you really have some extreme or unique requirements, are a professional who necessarily demands high resolution for the work they do (and even then, the argument can be made that we have enough resolution) or can't afford a $10k+ lens and need ever increasing cropping power, just about any modern digital camera from 12mp onwards will produce photos that can be displayed on the web or blown up to very large sizes without any real concern that you actually don't have enough image resolution.
So, all that said, yes, I agree that there is a larger market that wants better ISO, lower noise, higher FPS, better AF and tracking, better metering, etc. There is a really good reason fewer people are asking for more resolution...the need for it is not as real as some may think.