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Old May 13, 2006, 4:40 PM   #11
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But, we all know (or at least should by now) that the worst sin in digital imaging is to blow out the highlights
This is what I believed to be the truth ... maybe I would need to do more reading and do more tests ...tx for links. :idea:

Definitelly, I understand thatI will have more noise if I intentionally push my camera down -2/3 stops as I always do ...
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Old May 14, 2006, 1:00 PM   #12
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Here is the test I've done with 30D and +1/-1 bracketing. There is a substantial difference in noise level if exposure is stepped down. The test picture I've taken was inside the kithcen near the glass door and lows and highs coulnd't be properly exposed unless you take two pictures and combine them in photoshop.

Details on the left are from whatewer camera decided to do at P mode and on the right is -1 exposure with curves pushed in RAW to match the 'normlan' shot.

The difference is obvious. There is even change in color as well.

Increase in noise is just to dramatic comparing to SOME loss of details at highlights. I think I have to change my thinking in taking pictures with digital ...



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Old May 14, 2006, 2:27 PM   #13
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You need to think about your workflow.

The best exposure is to Expose To The Right (ETTR) without blowing highlights, even if this means your picture is overexposed. Then go into Photoshop and adjust your levels to get the right exposure.

Also as a general rule you can get detail out of highlights that are blown by the in-camera JPG conversion if you shoot RAW and use a better algorithm, the one for Photoshop is pretty good, but there are lots of others about. The difference between in-camera JPG processing and RAW processing is about 2 stops!! That is at a given exposure the JPG will blow out 2 stops before a good RAW converter will.

Which is a LOT. This is not very surprising if you think about it. RAW converters running on a PC processor usually take a few seconds to process the shot, on a processor that is 10? 50? 100? times more powerful. The Canon DigicII processor has 0.2 seconds to do its processing. So you can see why you can expect better results from doing RAW conversion on your PC.

For certain types of scenery I actually do exactly the opposite to what you do - I dial in +2/3 EV on evaluative metering and shoot RAW.

Always check your histogram after the shot to see how well you're doing on your exposures before you leave the scene.

As far as I'm concerned that's just about the only thing I use the LCD for - I try to get the composition right in the viewfinder before I shoot, and focus is impossible to judge on a small LCD. But what's really useful is the histogram after the shot.
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Old May 15, 2006, 1:14 AM   #14
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Tx for the tips. Certainly more experimenting on the way! This test was just to double check on ISO. I am not currently using anything else than Canon's software to manipulate RAW. New version of Photoshop (as well asearlier)is definitelly powerful on its own.
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