> Hi, > > Wanted to add: > Maybe the raw files contain the 22 bit data. If so, you can set the ISO > to anything you wish in the post prosessing (and as many times as you > wish). > May guess is this:
The signal is converted into 22 bits without a variable gain stage (like you say). The ISO setting is then applied in the image processor, along with various other (optional) adjustment steps, and the processed data is output as a 12-bit "raw" image. But the unprocessed input data is also saved temporarily, and may be run through the image processor additional times, if you change the processing parameters on the camera. Whether this "fully unprocessed" data can actually be read out, is a different matter. > > 5) With a relatively low gain amplifier and 22 bit A/D (and both having > low > noise) you will get a really wide exposure latitude. The K10D differs > from the competition in this respect. It is like how negative film > differs from > slide film. > It's been mentioned about two point six zillion times by now that you probably don't, though. The sensor itself doesn't have a lot more than 12-bits worth of latitude, so producing more bits in the A/D doesn't help a lot. Not amplifying the signal (in a variable manner) probably does help *a bit* as one source of noise has been removed (and the 12 bits are the latitude after noise has been chopped off), but it's probably not too significant compared to the noise in the actual sensor and/or the interface to it. - Toralf -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
