Getting full resolution from a 36MP sensor requires impeccable technique. Well, that is already true for 24MP—
36MP is not actually much more resolution
A reader emailed to ask:
What are your thoughts about the demands 36 megapixels will place on lens selection?
First of all, does such resolution even make sense?
Yes. Because while 36MP is 50% more pixels than the 24MP Nikon D3x, it’s only 22% more resolution (linearly, √1.5).
In terms of pixel quality, I expect that after 2+ years (Nikon D3x), sensor and electronics technology has advanced enough to mitigate the per-pixel quality challenge.
We were already there at this pixel density, or higher
Existing smaller sensor DSLRs already have photosite sizes similar to or smaller than a 36MP full-frame camera would have; the Nikon D7000 pixel pitch scaled up to full-frame would be a 37MP sensor. We’re already there in terms of pixel density.
Which given the lovely results from the NEX-7 pretty much eviscerates the concretized pixel-hating arguments see online these days. 36 megapixels is still a far cry from 56 megapixels, yet it’s decried as overkill by short-sighted folks lacking imagination.
Not just about resolution
A sensor with 36 megapixels can be thought of as just a higher sampling density, suitable for down-sampling to 24MP or 18MP to eliminate digital artifacts.
So even if technique and lenses are not scaled up to match the higher pixel density requirements of a 36MP sensor, the lens still delivers the same image to the sensor— so the higher pixel count can be used to produce a higher quality 24MP (or 18MP or 12MP) finished image from a 36MP sensor. This technique is covered in DAP. It works very well to eliminate digital artifacts on the finest of details. It might or might produce the same quality of color, but that is really a sensor design issue also.
Camera and lens tolerances
Camera and tolerances are already too sloppy. Unless tolerances are tightened substantially, 36 megapixels with a misaligned lens mount and sensor (yes, from the factory) is going to mean uneven sharpness, even with a perfect lens.
The viewfinder optical path and sensor optical path are already outside the required tolerances on many camera bodies (e.g. the two paths do not match in distance). Even shutter movement is a potential problem, so hopefully the D800 will work properly in Live View (no shutter movement, no mirror movement).
As proven in Making Sharp Images for both Canon and Nikon f/1.4 lenses, today’s DSLRs have focus consistency and accuracy adequate for perhaps an eight (8) megapixel camera.
It is hopeless for a 36MP camera. Yes, such cameras can be accurate with some lenses a good percentage of the time to within some tolerance deemed “reasonable”, but nowhere near accurate enough to be relied upon at wide apertures.
One can forget about optimal results with autofocus at f/1.4 and f/2 and f/2.8, except under ideal conditions with some luck. This means using Live View with a loupe, or having really good eyes and a perfect camera viewfinder, or just shooting more and getting lucky. Or that Nikon has somehow made a leap forward in AF accuracy (dubious).
Read about Lenses for the Nikon D800 / D800E.