>>Yes, the D700 really is "full frame". It has >>exactly the same 36mm x 23.9mm sensor as the D3. > >Forgive my ignorance, but I thought that full frame was 36mm x >24mm. If so, then the D700, like the D3, is not TRUE full >frame. > >What is the sensor size of the Canon full frame sensors? 36mm >x 24mm?
All sensor (and frame) sizes are nominal measurements only which must fall within the general 35mm size range or tolerance or call-it-what-you-will. For the record, the Canon 5D sensor is specified on Canon's web sites as "1.41 x 0.94 in./35.8 x 23.9mm". The Nikon D700 (and D3) sensors are specified on the Nikon web sites as "36.0 x 23.9mm".
For all intents and purposes, the Canon and Nikon sensors are identical in size. The fractions of a millimeter of difference in both of the sensor sizes fall well within the general technical definitions of what constitutes 35mm equivalency. The difference in final sensor sizes has more to do with the design and fabrication methods (chip design, wafer coverage, photosite integration, etc.) used to produce the different sensors than any other single consideration.
For the OP, the viewfinder and sensor are two completely separate things. The D700 viewfinder shows 95% of what the D700 sensor actually captures. In practice, missing 5% rarely (if ever) affects composition. It's inconsequential for all practical intents & purposes in my opinion. I think that I sometimes notice the viewfinder difference when I shift between my D700 and D3, but I can't really be sure. Technically the difference between the two viewfinders certainly exists, but I just can't tell the difference unless I do a side-by-side test with identical lenses on both cameras shooting the exact same object at the exact same focal length. Since I don't own duplicate lenses and have better things to do with my shooting time than run viewfinder coverage tests, I think the difference between the 95% and 100% viewfinder coverage is of academic interest only. The size difference between Canon and Nikon full frame sensors is utterly meaningless (even though the long side of the Canon 5D sensor is 0.2mm smaller than the Nikon sensor). It's meaningless.
Does the 1/250th of an inch difference really matter...?
Regarding Canon, the 1Ds MkIII is quoted as 36mm x 24mm, but the 5D is 35.8mm x 23.9mm.
The frame size on Nikon's DX DSLR's also differs by a tenth of a millimetre or two between cameras. As a matter of interest, the actual frame size varied very slightly between film cameras too, but nobody worried about it in those days
>24mm If so, then the D700, like the D3, is not TRUE full frame. Interestingly many 24x36 cameras were not precisely 24 x 36. 23.9mm is within half a per cent of theory - and better than some 24x36 film cameras. Interestingly because of the distance between film gate and film (probably 2-3mm) and varying lens exit angles most wide angles project a slightly larger image on film than most telephotos, so in that sense 24x36 or something a little different is part dependent on the lens in use. A D3 has 100% viewfinder coverage in the same way as an F6, F5, F4, F3, F2 or original F1. A D700 has a 95% viewfinder crop as do cameras like the F100, F90, F80 etc. Many DX cameras also have less than 100% viewfinder coverage - example being D200, D80 etc.
Photography is a bit like archery. A technically better camera, lens or arrow may not hit the target as often as it could if the photographer or archer does not practice enough.
Or to put it another way, you end up with a tiny insignificant more in your final image than what you saw in your viewfinder.
Afterall, that's the way most 35mm SLR cameras were (except for the Nikon F, F2, F3, F4, and few Canons)!
On the other hand, if you are doing ultra-precise scientific alignment to ensure that every last pixel to the very far edges and corners is accounted for in your compositions, then you might have an issue.
It's hilarious to read the worries that some people have about this issue!
Just to add to what the others mentioned, I'll make the point that the FX format is actually larger than what we were generally getting in practical terms during our film days. Why do I say this? Well, if you shot slide film, the slide holder masked a significant portion of the image. If you sent your print film to a commercial processor, they lopped off a similar amount. If you scanned your own film, you almost inevitably lost some area due to slight tilts or the aforementioned slide mounts. We actually get more usable area with today's FX format.
Except for those with darkrooms and use borderless negative holders and could get the full negative frame. Most photographic papers and digital photo printers do not have the same aspect as the negative or sensor, so there will still be croping.