On Jan 28, 2012, at 9:49 PM, Larry Colen wrote: > > > On 1/28/2012 6:29 PM, Paul Stenquist wrote: >> You can "expose to the right" or anywhere you choose by using exposure comp >> in any metering mode. The metering isn't based on jpeg or RAW. It's based on >> the light and what's in front of the lens. No meter is smarter than a >> photographer who understands how meters work. > > I'm certain that if I'm wrong someone will correct me. The metering mode in > our cameras picks a spot to meter on, and sets the exposure for that point at > midpoint. This means that if you look at the histogram, you usually get a > bell curve right around the middle of the graph, expose to the middle. This > means that if you go direct from RAW to JPEG without any compensation in post > processing, most of the pixels in the photo will be right around the midpoint > of exposure.
No. In multi mode, the meter uses a program to analyze the scene and tries to achieve a balance of highs and lows. If you don't like the histogram that results, you can move it right or left with exposure comp. You only get a bell curve in the middle when you have an average scene without extreme highs or lwows. > > What it does not do is look at the pixels out at the tail end of that graph. > If a bunch of them are off to the right, and you expose for the middle, then > you end up clipping on a lot of your readings, in other words, you'll lose > highlight detail. Then you bring that back in by dialing in negative exposure comp. > > Alternatively, if most of the readings are to the left of the point that is > metered for, then exposing for the middle will leave you with either a lot of > pixels that are clipped black, or a lot of your shadow detail lost in the > noise. Then you dial in positive exposure comp. Simple. > > The principle of exposing to the right has nothing to do with where you put > the peak of that bell curve, but that you expose the picture as much as you > can without clipping details in the highlights. In the first case, this will > reduce the exposure on the fat point of the graph, giving you a bit more > noise, but you won't lose information in the highlights. > > In the second case, you expose everything a bit more, then when you > compensate in post production, the noise gets reduced along with everything > else, improving your signal to noise ratio. Not entirely unlike how Dolby > noise reduction works, apart from Dolby being on an analog signal, and only > in certain frequency ranges, but still, amplify everything, signal and noise, > and then when you reduce everything, the noise is reduced. > > >> >> Perhaps, I'm missing something, butI don't know what you men by choosing 18 >> percent gray for shooting jpegs. You can use the spot meter and take gray >> card readings if you want a pure 18 percent gray exposure read. A histogram >> based on the raw might be nice, but it's not hard to interpret a jpeg >> histogram in terms of where you'll be with RAW. If you're edge to edge with >> jpeg, you're pretty much golden with RAW, and if necessary, you can push it >> beyond that a bit. >> >> Paul >> On Jan 28, 2012, at 8:58 PM, Larry Colen wrote: >> >>> Never mind raw on a point and shoot, I want my DSLR to properly support >>> shooting in raw. I want metering and histograms based on the raw data. I >>> want to choose metering modes so I can use "expose to the right" for raw, >>> and if I want to shoot jpeg I can choose 18% grey, or whatever they call it. >>> >>> For doing landscape and studio work, I fantasize about a mode that will >>> take a test shot (or three), examine the raw data and set the exposure for >>> details in the highlights or the shadows, or the bracketing for an HDR >>> series of exposures that will cover the full tonal range. I want a TAv >>> mode for the green button in M, so that I can set the shutter speed and >>> aperture based on a critical element of the photo, have it set the ISO, and >>> then just leave it there. >>> >>> Everything about using my camera indicates that raw is an afterthought, and >>> the UI is optimized for people that want a $1,000 point and shoot with >>> interchangeable lenses. >>> >>> -- >>> Larry Colen l...@red4est.com (from dos4est) >>> >>> -- >>> 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. >> >> > > -- > Larry Colen l...@red4est.com (from dos4est) > > -- > 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.
