Jonathan and Tim appear to be discussing two different aspects of COC and hyperfocusing. I'd greatly appreciate clarification of the relationship between these two, and thank Tim and Jonathan in advance for their response:
Jonathan argues that the 1Ds demands a more restrictive COC than does film:
I don't think our positions are incompatible. What Jonathan is getting at (if I may take the liberty) is that you might as well maximize sharpness since the ultimate purposes for which most folks would use the 1Ds are not 8x10 (you don't need a 1Ds for 8x10s) but larger. If you're shooting for large framed, displayed prints the more conservative a COC you use the better.
But in the end there's no free lunch - the sweet spot is f8 - f11 +/- for most lenses, and as you move towards f32 other un-desirable stuff starts to happen. Ultimate DOF is going to be driven by lots of comprimises to the photographers intent. Is there motion? - problematical for long exposures. What's the composition, WA lends itself naturally to deep DOF, but not telephotos or macros.
The issue is important if you are using a calculator, since it will very likely use .03 or thereabouts for full frame and amend that for the smaller sensors (if it's a "good" calculator). If you need to factor in size of print etc. the "standard" coc is going to be misleading and you might as well use Jonathan's suggestion.
My only caveat is that even being conservative in using a smaller COC, I'm still not convinced that a 1 pixel COC is appropriate. I don't have the math, I'm simply recalling other discussions.... The question is under what size/viewing conditions is a 4 square block (next logical size up from 1 pixel) perceived, not as a point, but as a disk - that's a testable question.[/font]