Pentax DSLR DiscussionTalk about Pentax Digital SLR technique here, including the *ist D series, the K100D series, and the K10D, K20D, and K200D models.
Dan, that is sensor blooming. Common and avoidable by avoiding long exposure > 1 sec with smaller aperture.
Underexpose the shot a few more stops will reduce this problem too.
A common problem with digital night photography
James; I was referring not to the bloom itself, but to those strange Egyptian-like patterns present. Is that bloom, sensor error, or is it just the way they're supposed to work?
Maybe this'll help my cause. See the patterns I'm referring to?
This is the first time I've noticed these patterns.
Is this normal? Or just funky?
Its normal for digital cameras but I'm afraid your K100D is (much) worse than mine, honestly.
In fact, some models are less visible for this artifact than the others but even for the same model, some are better and some are worse. It is just a matter of design difference, individual hardware difference (for the same design) and calibration differences.