Hi Rob, > Personally I've rather the camera was engineered to minimize the > occurrence however in certain conditions (which you found)
me too. OTOH I can live with it. But it's always good to know limitations of the system beforehand. > occasionally even a spacial frequency of multiples of the native > resolution will cause visible aliasing. As others have mentioned the > crops are dark but of course that's nothing to do with the aliasing > which is plainly visible as a rainbow across the grille of the right > vehicle after auto-level adjustment. Looking at the blue bus sign at > the rear it's obviously that the grill bar frequency is far less than > the system resolution, so in this case I'd suggest that it's more a > problem in the RAW convertor, ie how it deals with regular high > frequency pattern data. unfortunately, all converters I've tried failed on that one, including the latest ACR v3.6. Not that I've tried every RAW converter out there. Tomorrow I'm going to try Capture One and probably Lightroom as well if time allows. > The colour noise reduction tool isn't designed to manage aliasing > errors, it's primary purpose is to manage chroma noise which becomes ok, but it did a very respectable job on another of my test shots with visible moire. > more prevalent as ISO is increased. It's really a case of suck it and > see, sometimes RAW software doesn't behave the optimally so we have to > compromise. In the case of the radiator grille I'd simply create a > rough mask and desaturate it. that basically what I did (well, I used a slightly different technique using a paintbrush in color overlay mode, because it's perhaps faster on such a small area). Cheers, Peter -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
