On Jan 25, 2008, at 1:27 PM, Adam Maas wrote: > On 1/25/08, Mark Roberts <[EMAIL PROTECTED]> wrote: >> This raises an interesting issue. When Michael Reichmann tested the >> Canon 1Ds-III, he said he suspected that its sensor was out-resolving >> its lenses. In other words, the lenses didn't have sufficient >> resolution to really take advantage of the sensor. A little math >> shows >> the 24 x 36 sensor in the Canon checking in at 138 pixels per >> millimeter (linear). The 14 megapixel Pentax sensor (23.4 x 15.6) >> comes >> in at about 198 pixels per millimeter! >> >> Now granted, the 1Ds-III does have the disadvantage of using Canon >> lenses <g>, but I'll be really curious to see images from the K20D >> taken with some of the Limited series... > > Remember that lens resolution lessens as you approach the edges. I > seriously doubt the 1DsmIII comes close to outresolving its lenses at > the centre, but even the 5D had issues with this at the edges. It's > likely that the 1DsmIII has such issues with more lenses and further > away from the edges.
I had the A50/2.8 Macro serviced some time ago and while it was at the shop, my technician friend checked the collimation on his optical bench and did a resolution test. I know it is capable of resolving at least 100+ [EMAIL PROTECTED] ON the Pentax *ist DS, I was able to get about 47 [EMAIL PROTECTED] out of it. On the K10D, I was able to get about 62 [EMAIL PROTECTED] out of it. I was also able to get these values out of the DA14 (on center, that's all I was measuring). I am sure that if the K20D has 20% more resolution than the K10D (that is, resolves about 75 [EMAIL PROTECTED]), the A50/2.8 is up to the task and I'm pretty sure the DA14 will be too. At least on center. ;-) Can't speak to the 1Ds-III but, frankly, I was never particularly pleased with the Canon lenses in the range of focal lengths I use by comparison to Nikon, Pentax or Olympus lenses. Canon's lens suite is very biased to the long telephotos, almost a specialization, IMO. Godfrey -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
