>Just because I call you rude names doesn't mean that I disagree with you, or >even that I dislike you.
MARK ! -----Original Message----- >From: Larry Colen <[email protected]> >Subject: Re: Why Not RAW Format on ALL Digital Cameras? > > >On Jan 29, 2012, at 1:13 PM, Godfrey DiGiorgi wrote: > >>> I also agree with Godfrey on ease of manual use. >> >> I'm glad we agree on something. ;-) > >Just because I call you rude names doesn't mean that I disagree with you, or >even that I dislike you. > >> >>> Part of the issue with digital exposure is that there is so much more >>> information potentially available that a simple match needle would through >>> away too much useful information. >> >> I disagree. Until sensors data can be addressed to manipulate the >> capture data by photosite address, you will always have one exposure >> addressing all the photosites the same way. Whether you get there with >> some ultra-smart evaluative metering system, or you use your brain as >> the computational system and a meter as the dumb data input, the end >> result is always an ISO @ aperture @ exposure time. > >Yes, a scalar meter for a scalar setting is about all you can do. But there >is a lot more information available from a histogram than from a match needle, >and even more if the camera takes a test shot and reads the value of every >sensor site. > >There are many times when a match needle, or an AE system that follows the >match needle is good enough, or the best available. > >As to manipulating capture data by photosite address, there are times I'd >settle for being able to set the ISO of each color channel separately. >I often have to underexpose two of the channels by a couple of stops to keep >from blowing out the third channel. > >> >> 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. > >Very true. How do I find 5% below the saturation limit of my sensor when the >histogram only tells me the values on the JPEG, not on the sensor? I'll note >that your M9 gives the sensor values, not the jpeg values. > >> Writing computational automation to understand the characteristic >> curve of the sensor @ a specific ISO setting, analyzing the scene to >> determine what is or isn't important, and setting that single exposure >> point consistently ... Well, it's not that it can't be done, but it's >> way more than most current in-camera computational processing is >> capable of. > >In the time available for action shots. But what if you had a mode where you >could press the "analyze" button, and let it churn away for a few seconds? >How long would it take to read 16M values into a buffer, and note the maximum >and minimum values? > >> >> I do this in my head faster than I can think about it. My E-5 had >> Spot-Hi and Spot-Lo modes for metering complex scenes that simplify >> manual metering (by comparison to just Spot in most other cameras, >> which is based on 18% reflectance reference). > >I suspect I do a lot of this intuitively myself. > >> >> With almost all cameras, I set my metering to centerweighted >> averaging, evaluate the pattern, and use aperture priority AE or >> manual mode. With the APAE mode, I look at the scene, see the dynamics >> of the hot and dark areas, and tweak the EV comp to suit. With Manual, >> I set it to the meter's null point then tweak it up or down the same >> way, OR I just know what the scene type requires from past experience >> and set it. My brain does this without me consciously thinking about >> it, and FAR more consistently than any exposure automation I've ever >> seen. > >Do you check your results with the histogram, or just decide that you're good >to go? > >> >>> Another issue is that digital isn't as tolerant of missed exposures as >>> film, though at ISO 100 the K-5 may be far more tolerant of underexposure >>> than most film. >> >> I don't find this to be true in general. Digital capture is more >> sensitive to the saturation point than film because it's a hard clip >> rather than a slow roll off, but it generally has more dynamic range >> and, as long as you're under the clip point, is much much much more >> manipulable. What's important to keep aware of is that as ISO >> increases, DR decreases so if you're looking at scenes that require >> elevated ISOs for hand-holdability or subject movement, you have to >> understand that the DR will be decreased and pick your important >> detail areas more carefully. > >All of this is true. > >> I don't know of any automation system >> that can do this pre-exposure ... they simply don't have enough data >> to work with like your eye and mind does. > >Exactly, that is why I want a mode that will take a test shot, or test shots, >analyze the data post exposure and report on the ideal exposure based on the >scene, and your tolerance for blown out highlights. Ideally, it could do the >test shots, and even set optimal values for an HDR range for scenes that may >have something like a neon sign on a dark street where one exposure is ideal >for the sign, it skips four stops of exposure where the sign is over exposed >and the street is underexposed, and another exposure for the street. > >This wouldn't work for sports photography, but should be trivial for a lot of >slow process situations. >>> > >-- >Larry Colen [email protected] sent from i4est > > > > > >-- >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. -- 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.
