On Jan 29, 2012, at 4:53 PM, steve harley wrote: > on 2012-01-29 14:13 Godfrey DiGiorgi wrote >> Knowing the characteristic curve of a sensor and how digital image >> data exposure operates, it's very easy to 'place' the exposure where >> you want it with a spot meter and a moment's thought: with the >> brightest area of significant detail 5% below the saturation limit. > > okay, if the spot meter is cued to 15% gray, that means i'd meter as above, > then adjust exposure plus whatever the fractional number of stops between 15% > gray and 5% below saturation might be on my camera; i suppose i could test > that and memorize the adjustment for key ISO values (as the headroom varies); > i could preset that bias and be fairly efficient when highlight clipping is > my main concern.
You can test for the difference between gray and 5% below clipped highlights. You'll find it's about two stops. But you can tell by looking at a jpeg derived histo as well. If the highlights are clipped just a wee bit, you're golden. > > but often i want to choose how much highlight to blow based on how much of my > shadows i want keep from turning to mud; and sometimes i'm willing to blow > one channel if i can count on keeping some contrast in the other two ... > that's when the histogram helps because the best exposure is often not > absolute, it's a creative compromise > Exactly. And the histogram on my K-5 works well for that. While the histo may be based on a jpeg, the jpeg is merely the camera's conversion of the RAW. It's in a smaller color space than I work with and it may clip highlights that are useable in RAW conversion, but with some experience it's easy to predict where those lie. Paul > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
