The Pentax DSLR cameras' metering systems are calibrated to produce accurate exposure estimation for their *default* configuration ... JPEG capture (and in the case of the *ist DS, BRIGHT color rendering). They don't recalibrate for RAW exposure, where accurate exposure estimation should be greater due to RAW files' improved headroom.
That's why what you're seeing is JPEGs that are brighter than RAWs when viewing RAW+JPEG capture in Lightroom, where you haven't told Lightroom to ignore JPEG sidecars. With the *ist DS, I typically found that I needed to add +.3 to +.7 EV for all RAW captures. The K10D's bias is more accurate, I'm typically adding only up to +.3 EV for average scenes. These biases in meter calibration are also, I feel, a reason why some people shooting with RAW capture tend to complain about noise. My Sony R1 actually recalibrated the meter when I turned on RAW capture, it adjusted the bias such that average scenes never required EV compensation. Godfrey On Apr 30, 2008, at 8:07 PM, Stan Halpin wrote: > To amplify just a bit on Godder's reply... > > If you shoot a few frames as RAW+JPEG and then import them into LR, > it is easy to see at a glance which are the JPEG (lighter) and which > are the RAW (darker). I was reminded of this last night while > scrolling through way too many thumbnails to try and find a shot of > my mother-in-law that my wife needed ASAP... (Don't anybody mention > Keywords to me. I know all about them and sometimes even use them. > Just not on shots that I have any reason to look for later.) I came > across a bunch of duplicate shots, with one version lighter than the > other. It took my work- and wine-befuddled mind a while before I > realized that they were from the brief era when I was doing the RAW > +JPEG thing. (Don't ask why, I haven't a clue. It must have seemed > like a good idea at the time.) The camera does its magic processing > of RAW to JPEG, saves the result and/or puts a small version of it on > the LCD for you to view. And uses that JPEG version as the basis for > its scene analysis which yields the histogram. You need to do that > processing yourself with the RAW output. Which I usually find usually > involves adding some exposure or fill-lighting. This was true with > the *ist-D as well as the K10D. > > stan > -- 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.
