About banding at 1600ISO David Savage observed, "Downsizing & sharpening for web sometimes highlight it."
I wonder, does the downsizing and sharpening highlight the banding, or introduce it? When I put Ken's picture, which BTW is a cracking good shot, into PhotoME to read its entire exif data I saw that the reduction factor from original to web-sized is about 5.2:1. I reckon the odd reduction factor plus the conversion from 16 bit RAW to 8 bit jpeg is as likely a source of banding as is the camera. The bitdepth reduction can bring in posterisation bands if the levels have been massaged more than a little, which can then be aggravated by jpeg artifacts. I do see jpeg artifacts in the area Dave refers to. The cleanest resizing is always at factors of halves, quarters, eighths, doubles, four times, eight times and so on. Regards, Anthony Farr > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of > David Savage > Sent: Wednesday, 21 May 2008 11:56 PM > To: Pentax-Discuss Mail List > Subject: Re: PESO - Not the usual Bleeding Heart > > Yeah. It's subtle but I can see it in the large area of green in the lower LHS. > > I find that it occurs with shots made at ISO 1600. Downsizing & > sharpening for web sometimes highlight it. > > Anyway, it's still a nice shot. > > Cheers, > > Dave > > 2008/5/21 Ken Waller <[EMAIL PROTECTED]>: > > Thanks for looking & commenting Dave. > > > > Vertical banding ?????? > > > > Kenneth Waller > > http://www.tinyurl.com/272u2f > > > > ----- Original Message ----- > > From: "David Savage" <[EMAIL PROTECTED]> > > Subject: Re: PESO - Not the usual Bleeding Heart > > > > > >> Nice colours, but the vertical banding is a nuisance. > >> > >> Cheers, > >> > >> Dave > >> > >> 2008/5/20 Ken Waller <[EMAIL PROTECTED]>: > >>> Check out http://mypeoplepc.com/members/kwaller/offwallphoto/id2.html > >>> > >>> Taken with K20D, 200mm f4.0 ED Macro SMCP A*, f7.1 @ 1/200, +1.3, ISO > >>> 1600 > >>> on Bogen 3221 tripod with Bogen mini gear head. > >>> > >>> Comments solicited & appreciated. > > > > > > -- > > 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. > > > > -- > 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. -- 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.
