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09-12-2008, 07:40 PM   #31
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[quote=Marc Sabatella;341262]
QuoteOriginally posted by FHPhotographer Quote
In this case, deal with the camera-RAW histogram disconnect by not using the histogram
[/quotes]

That doens't really make much sense. It might not match *exactly*, but it's going to be pretty darned close - a hell of a lot closer than you'll get by ignoring it and guessing - even guessing based on blinkies (which, I'll bet, are also going to be based on the in-camera JPEG conversion engine).
I am pretty sure the blinkies are based on jpg output. However, I get close to ETTR by making sure I have a specular highlight blinking red. As I shoot RAW, that puts me pretty close. There seems to be about a stop more on either end of the dynamic range in the RAW file compared to the in camera jpg. I really start to look at things carefully when I see blinking in the dark areas.

09-12-2008, 08:37 PM   #32
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Red blinkies

[QUOTE=Canada_Rockies;341390]
QuoteOriginally posted by Marc Sabatella Quote
I am pretty sure the blinkies are based on jpg output. However, I get close to ETTR by making sure I have a specular highlight blinking red. As I shoot RAW, that puts me pretty close. There seems to be about a stop more on either end of the dynamic range in the RAW file compared to the in camera jpg. I really start to look at things carefully when I see blinking in the dark areas.
I've got to upgrade the K100, just to see red "blinkies" if for not other reason
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09-13-2008, 10:29 AM   #33
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[quote=FHPhotographer;341430]
QuoteOriginally posted by Canada_Rockies Quote
I've got to upgrade the K100, just to see red "blinkies" if for not other reason
FHPhotog
The k100 has highlight warnings, but not dark area warnings. The highlight warnings may not be red ...
09-15-2008, 02:12 PM   #34
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I find the histogram useful, but I don't get very technical with it either. I actually rely more on the blinkies in a matter similar to Canada_Rockies' method. I try to reduce the blinkies to the point where there aren't any massive areas blown out (or increase exposure to get a few if I am underexposing).

I take comfort in knowing that the histogram and blinkies represent the on screen JPG, and so I target some minimal amount on the over-exposure side (I like ETTR for my workflow).

The histogram comes into play for me when I have a difficult / contrasty scene. It allows me to see just how much I might be able to adjust the exposure to get a better shot either + or -.

All-in-all, I just use these things as rough guides and as an improvement over a light meter without the expectation that they be perfect, especially since I am not perfect anyway. As long as I am close to what I want, I can then take comfort in knowing that processing might (I'm not very good at it) get me to my vision, and that I won't need to do much processing to get that vision.

Never-the-less, a recent experience has provided me confidence in just how much I can allow that histogram to stray from the ideal and still salvage a decent shot even for a high ISO, underexposed image.

09-15-2008, 02:44 PM   #35
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QuoteOriginally posted by Canada_Rockies Quote
Oh, yeah, and when I pushed TriX to 3200 back in the early 1960's, the only thing I had to worry about was adjusting the developing to make sure I had a printable image. This is the same problem re-iterated in technospeak. You will get gobs of digital noise using the suggested procedure, just as I got grain the size of golf balls pushing ASA 160 TriX to 3200 ASA. I'll adjust the ISO, thanks.
Well it depends on the developer actually and the fact that your camera "processing" is what removes the noise. Same you can do post process. Clip black point lower and shadowy noise disappears. bit of gaussian blur, more gone............. At any iso and the IDENTICAL exposure parameters the EXACTLY the same amount of light is falling on the sensor. Think in those terms.
If the correct exposure at 1600 iso is f8 at 1/60th "underexposing" 2 stops at f8
1/60th at iso 400 allows the EXACT same amount of light to fall on the sensor...
There is no "magic sensitivity' adjustment. Just electronic processing... At least as I understand it.
If you are really curious gat a RAW processor OTHER THAN ACR and try it yourself. Same exposure, different iso's.
Re: Why bother changing base ISO?: Nikon D3 - D1 / D700 Forum: Digital Photography Review
Another way to put it........
> True, except that if you bump the iso the image is not properly exposed.

Yeah but the sensor doesn't really have a concept of properly exposed. I think people think that exposing to the right means you're filling the photosites to full well capacity with photons. The "right" is just a histogram calculated from a final image.

Say 1/500th, f/5.6 and ISO800 creates a JPEG that is exposed to the right on the histogram. This will take X many photons, average, per photosite, and X < full well capacity. Now say you make another jpeg at 1/500th and f/5.6, but at ISO100. You are 8 stops from being "properly" exposed to the right. BUT, a key point is that your sensor has received the same X photons per photosite, since the exposure was the same, and we'll assume conditions didn't change. Since DR and noise is all about the noise floor, how could the ISO800 picture end up looking better than the ISO100 one that was boosted 8 stops in PP, since for each exposure, the exact same amount of light was captured by the sensor?

Re: Why bother changing base ISO?: Nikon D3 - D1 / D700 Forum: Digital Photography Review

Last edited by jeffkrol; 09-15-2008 at 03:15 PM.
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