On Jan 29, 2012, at 4:13 PM, Godfrey DiGiorgi wrote: >> I also agree with Godfrey on ease of manual use. > > I'm glad we agree on something. ;-) > >> 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.
Exactly. This doesn't have to be complicated. > > 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. > That's in practical terms the only thing you can do ... anything else > you do is a matter of processing the raw data (setting the appropriate > blackpoint, colorspace, and rendering curve to suit the dynamics of > the scene). > > 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. > > 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). > > 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. > Exposure compensation is the digital photographer's best friend. It's a great tool. >> 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. That's the beauty of it, and I think all of us who worked with film for so many years can appreciate that. The RAW converter is a hell of a lot more flexible than the developing tank and the enlarger. Paul > 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. 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. > > On Sun, Jan 29, 2012 at 12:33 PM, Larry Colen <[email protected]> wrote: >> Steve, >> >> I get the feeling that you are the only one that actually understands what >> I'm saying. >> >> On Jan 29, 2012, at 11:20 AM, steve harley wrote: >> >>> on 2012-01-29 05:29 Paul Stenquist wrote >>>> >>>> On Jan 29, 2012, at 12:16 AM, steve harley wrote: >>>> >>>>> on 2012-01-28 21:57 Paul Stenquist wrote >>>>>> That's basically what today's best meters do. But they still can't gauge >>>>>> reflectivity and color as well as the human eye can. The meter makes a >>>>>> call and a good photographer makes the necessary adjustment. Most of the >>>>>> time the meter will come close enough for all practical purposes. for >>>>>> those times when it can't the photographer has to lend a hand. It >>>>>> wouldn't be much fun if machines did all the work. >>>>> >>>>> i submit that most of us don't have "today's best meters" >>>> >>>> The K-5 comes somewhat close, but no it's not at the top of the heap. But >>>> it's more than good enough when photographers use their brain as well as >>>> their meters. >>> >>> that may be, but i suspect that 1) most of us don't have K-5s, and 2) even >>> much worse metering systems are "good enough" — we can learn to compensate >>> for anything; some of us whose professions are to designs ways to exploit >>> technology, however, will instinctively imagine extending tools as far as >>> is possible and efficient >> >> This is exactly what I'm doing. My career is to write embedded systems >> software. Designing and writing the software for setting the exposure of a >> camera would be a job that my 30 years of professional experience is almost >> ideally suited for. I recognize the limitations of the automatic systems, >> know to check the exposure against the aids (histogram and blinkies). What >> is frustrating is that those tools could give me exactly what I need, but >> they don't. They tell me if the JPEG, which I don't use, would be properly >> exposed, I want to know what is happening on the sensor. >> Rather than red blinkies for over exposed and blue for underexposed portions >> of the jpeg, which will change if you change the color balance, how about >> red blinkies if you are clipping the data on the sensor, and yellow blinkies >> if you are close enough to the limit of resolution that you'll get >> posterization (or whatever you call it when you get those annoying lines in >> the sky). >> >>> >>> so as i gravitate toward a more manual process, i imagine the kind of tool >>> i want to work with; the histogram (preferably representing RAW exposure, >>> and live) simply offers a more direct means to an end; a camera's meter >>> just gives one data point; we have to guess how it has evaluated the scene >>> to get the what histogram gives us directly (or spot meter several points); >>> i think the histogram is a better tool for using our brain in conjunction >>> with our meters, and is better suited to intelligent but spontaneous >>> photography >> >> Exactly. There are times when metering off the sensor would slow things >> down too much, use too much power, generate too much heat etc. But there are >> also times when it is the perfect tool. >> >>> >>> i could even appreciate an interface that applies a little more calculus to >>> image data to indicate where in the image, and at what levels, the angle of >>> the histogram's curve is steepest and shallowest, which is part of what i >>> sort out (less effectively) with my brain now >> >> >> I also wish that they'd tell me exactly what each of these modes does, >> rather than when I'm supposed to use them, and let me guess what the camera >> is doing. I understand that most people are happy with a magic box that >> does their thinking for them, so that they don't have to think about >> anything but composition, but at least tell those of us that want to know so >> that we can decide when to let the camera think for us, and when we should >> think for ourselves. Instead, I'm left with having to always check the >> histogram and blinkies, which *almost* tell me what I need to know. >> >> It's interesting how many people seem to despise the viewfinder that doesn't >> show the whole image, but don't seem to mind the histogram that doesn't show >> all of the information. >> >> I also agree with Godfrey on ease of manual use. 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. 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. When I got my K-5 I thought that I would not >> need to get a katzeye screen for it. The stock screen seems a lot better >> than previous cameras, and the autofocus is a lot better. However, I still >> find myself missing focus in so many cases where if I had a good manual >> focus screen, it would be trivial to nail focus perfectly. >> >> Again, it's a case of optimizing the system for the automatic functions, >> that don't always work as well as manual. >> >> >>> >>> -- >>> 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. >> >> -- >> 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. > > > > -- > Godfrey > godfreydigiorgi.posterous.com > > -- > 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.
