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12-16-2009, 09:13 PM   #1
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Dynamic Range Extension Shadow Clipping in bokeh

I usually leave the DR extension setting off on my cam, but tonight when testing out the various features of the K-x I've tried it on.

Noticed a shadow clipping appearance when DR is turned on - check out the compare shots here:

K-x DR test - a set on Flickr

I think I will keep leaving my off for most situations...

12-16-2009, 10:20 PM   #2
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First off it looked like JPEG compression - have you set the compression to a minimum?

At first I thought it should be the opposite, but then I realized you're probably doing highlight correction, not shadow correction.

Shadow correction should bring out more detail in the shadows and make it smoother.

Highlight correction would indeed bring noise and possibly bring out distinct steps in shadow detail out - highlight correction works by underexposing 1 stop and pushing everything but the highlights in software.
12-16-2009, 10:37 PM   #3
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The original file is raw and the clipping was not resulted from JPEG clipping.

Indeed this is caused bu HL expansion - I tried using Shadow expansion (along with highlight expansion of course), and the dark area clipping still happens - try it yourself.

HL expansion is probably useful under certain conditions but I will leave it off most of the time.
12-16-2009, 10:41 PM   #4
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I'mm rethinking... HL DR is useful when the scene on a whole is bright and there is no distinctively very dark areas. So, it would be useful in a day light situation, but maybe not in a dark museum with bright lit objects (or a car show), or night scenes...

Which makes sense LOL!!! I'm pretty old fashioned and take time to warm to new tricks camera can do, so need some time to think things through and warm to them ha.

12-20-2009, 04:57 PM   #5
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QuoteOriginally posted by Katsura Quote
The original file is raw and the clipping was not resulted from JPEG clipping.

Indeed this is caused bu HL expansion - I tried using Shadow expansion (along with highlight expansion of course), and the dark area clipping still happens - try it yourself.

HL expansion is probably useful under certain conditions but I will leave it off most of the time.
You converted it to JPEG and thus it is subject to JPEG compression...

There does not appear to be any clipping (that would be loss of the extremes) but rather a non-smooth gradient - that effect is notorious in JPEG compression but could also come from , as I said, pushing shadows (highlight saving).

HL DR is useful for saving any highlight detail, regardless of the rest of the scene. Many prefer to simply underexpose using EC and correct themselves in PP instead of leaving it up to the camera, which may not be as good.
12-20-2009, 06:42 PM   #6
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I see the clipping. There's a clear difference between the two pictures (if you stare at the part of the screen you expect to clip). And to me, that doesn't even look like JPEG compression either.
12-21-2009, 12:15 AM   #7
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My bad, it looked like JPEG compression because remote desktop actually appears to be compressing the screen before sending it over to my screen.

Still doesn't look like clipping (detail being shoved to black) to me but just the effect you get when you take the lower less precision detail and multiply it by a gain. If you PP yourself, you could probably do a more less linear re-map compression when converting to JPEG and got a better result. The "detail" that is lost in the black part appears to just be noise and not detail.

I don't believe highlight correction has an effect in RAW other than it being underexposed 1 stop outside of sillypix

Last edited by Eruditass; 12-21-2009 at 01:11 AM.
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