On 21 Oct 2005 at 9:42, Godfrey DiGiorgi wrote: > I always use somewhat tighter, if not necessarily optimally sized, > hoods. > > But I don't think that this is the cause of the problem. The cause > seems to be a combination of underexposure and effects of fluctuating > power. I've never seen this kind of banding on any of my cameras > without underexposure at least.
I performed some sloppy tests a while back, I put a set of nearly flat AA Ni-MH batteries in my *ist D, popped in a Microdrive, opened up the flash, put it in AF, set the ISO to 3200 and fired off shots one after the other in RAW mode until the batteries would do no more. I also had an ultra-bright LED in the feild of view which I shot in, just out of and completely out of frame. Most of the images contained no banding however a few did and those I suspect were the ones that were shot with the LED just out of the feild of capture. What I did determine from the somewhat haphazard test is that the power system in the *ist D at least is very stable and I would suggest is not the source of banding. Banding happens in rows and seems to be a read-out flaw which could be noise/power related or potentially due to the latent photosensitivity of row electronics on the sensor. 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
