On 14/04/07, Brendan MacRae <[EMAIL PROTECTED]> wrote: > What's the deal with film camera lenses and chromatic > aberration on the K10D? > > Shooting wide open is a nightmare for me. Is anyone > else seeing this issue? Is it endemic with film lenses > plus the smaller sensors? It can't stricly be a > function of older glass since I have seen ED IF lenses > having the same trouble on the K10D. Perhaps only the > newest of the newest coatings are fixing this issue?
It's endemic with most lenses, digital sensors just tend to exacerbate the problem, different coatings would make little difference as the source is lens aberrations. Fortunately CA is also easy to manage when post processing RAW images. > I tested the FA31 Ltd, the A*85 f1.4, the A50 1.4, and > the FA 24-90 today, all wide open, RAW, ISO 100, and > all of them were showing some amount of color > fringing. It didn't go away until 2-3 stops beyond > wide open on any of these lenses. I'm wasting time > trying to fix the problem every time I shoot for > shallow DOF. Would a full frame sensor make any > difference in this regard? A FF sensor would likely make the CA more apparent as the angle of incidence would be more acute towards the edges and the lenses will exhibit more distortion towards the edges. > How do the DA lenses handle this? Are they free of CA > wide open? One hopes as I have my eye on the DA10-17mm > and the DA*50-135mm. Don't hope too much, the DA lenses seem to be all over the place some, exhibit slightly better CA, some worse than their rough A/FA counterparts. -- Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://home.swiftdsl.com.au/~distudio//publications/ Pentax user since 1986, PDMLer since 1998 -- PDML Pentax-Discuss Mail List [EMAIL PROTECTED] http://pdml.net/mailman/listinfo/pdml_pdml.net
