2009/9/1 Boris Liberman <[email protected]>: > Ralf, I did some night photography (exposures no more than 30 sec, > inclusive) and it seems that K-7 does not do dark frame subtraction in this > case, or may be it does it somehow faster, as there were no delay between > the shutter closing and picture being available for review.
I'm not Ralf, but did an experiment with long exposures myself this week-end. My K-7 does not apply d-f subtraction at 30 seconds exposures either. Since I had forgotten my remote at home, I tried to make a four-minute exposure by doing an 8 parts multi-exposure. This, too, came without d-f subtraction. For B-mode however, it is not possible to turn d-f off at all. That said, my long exposures with K-7 exhibits some rather nasty vertical banding. The multi-exposure amplified this. Tried to subtract a d-f created back home after the trip, but with only limited success. It removed a fair bit of noise, but not the banding. I checked with my pusher that my camera is not faulty. A google on banding in digital cameras indicates that some Canon models have been prone to this over time too, and that it generally is solvable by firmware upgrades. Fingers crossed that Pentax will provide one. As it stands, though, I have to agree with Ralf that the K-7 is not optimal for night shooting. Jostein Jostein -- http://www.alunfoto.no/galleri/ http://alunfoto.blogspot.com -- 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.
