On 6 Jan 2006 at 21:35, J. C. O'Connell wrote: > I was just thinking that the differences in resolution, > active image circle, and sensitivity to incidence angle > of FF film vs. 6MP APS digital might make signifigant > differences in which lenses to buy/sell. Two lenses different on film might > be > same on 6MP-APS-D or two lenses same on film might > be different on digital or one lens that's better > on film compared to another might actually be worse > on digital compared to that same other lens, etc.
It would be a useful resource but hopefully it would be redundant in the not too distant future, why I say this is that so much depends on the sensor. Resolution is currently limited to around 47lppmm max so a lot of the better lenses are virtually better than the sensor through their whole aperture range. Comparing them to film performance would take some dedication too, it's likely that you could get a range of people to shoot a standard test target with DSLRs but I'd bet that few would be willing to pull the cash out to do it on film too. Regarding the problems due to angle incidence there seems to be a few WA lenses more prone than others but the ones that remain sharp to the edges can be pretty easily corrected for CA. Straight fall off I think seems better for most lenses due to the reduced crop. > For example a high end wide angle model "a" might > be clearly better than model "b" on FF film due > to superior corner sharpness. But if this superior corner > sharpness region is entirely out of the area covered by the APS > sensor, then lens "b" might be virtually identical to "a" > on 6MP-APS-D. And so on... I think apart from some edge CA problems most lenses behave pretty much the same way on film as they do on the DSLRs, I suspect why there is so much more talk about lens quality these days is that poor lens performance is so much more visible now that so many people can easily get a high quality image to screen at 1:1. I just dug up a series of test shots of a USAF target that I made very early into my time with my *ist D, they cover each full stop for the A50/1.8 macro, A50/1.4 and A50/1.2, you are welcome to a copy but even zipped up the bundle of 31 files is around 48MB in size and I don't have spare web space to host them. I could ftp the bundle to anyone with some web space to spare. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
