On 13 September 2010 04:13, Boris Liberman <[email protected]> wrote: > Hi! > > Reading the discussion between Ralf and others regarding the type of night > shooting that Ralf excels in, and idea occurred to me. > > Please have a look: > > http://pentax-ways.blogspot.com/2010/09/on-dark-frame-subtraction.html > > What would you say? > > Thanks. > > Boris
This is what astronomers do on ground and space-based telescopes. The issue with cameras is that the dark frame needs to be the same exposure length as the image you take; for your system to work one would take a 1/2 hour exposure (say) and the camera would figure out what the noise would be every (say) 30 secs, and would then use this data to apply a DFS for exposures henceforth. Ideally, you would be able to run a "DFS Setup" at any time and the camera would store these values in memory. It would come with default values from factory, but as the chip ages one would have to redo the setup periodically. Or if you're a stickler for detail, you'd do it at the beginning of every night you use the camera. Or...Pentax could just make DFS optional so those who want to turn it off and do DFS with software of the computer can do so, and those who don't know what the hell DFS is (or don't care) will leave the camera on the default "DFS: ON". For what it's worth, even a camera like the Panasonic G2 has the option to turn DFS off, so there's no reason for Pentax not to implement it. --M. -- \/\/o/\/\ --> http://WorldOfMiserere.com http://EnticingTheLight.com A Quest for Photographic Enlightenment -- 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.
