Author Topic: Sticky LCD exposure correction for ettr shots?  (Read 2969 times)

Marsu42

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Sticky LCD exposure correction for ettr shots?
« on: February 17, 2014, 08:10:45 PM »
One problem with ettr shots is that they look horrible on the lcd and any newbie wouldn't suspect this is actually an excellent exposure if treated correctly in postprocessing. Personally, I often have a hard time figuring out if the shot is ok in other ways than the exposure so I use the exposure correction via set+wheel or left/right cursor keys.

My idea: Automatically determine what exposure correction is needed for ettr shots, and sticky this to the preview of this shot so apart from the histogram the shots looks "normal" like non-ettr. As a side effect, it's usually also easier to see where blown whites might be.

a1ex

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Re: Sticky LCD exposure correction for ettr shots?
« Reply #1 on: February 17, 2014, 08:19:43 PM »
I believe one should find a way to adjust the exposure compensation in the JPEG preview somehow, without altering the raw data. I had an attempt right before finding the photo raw buffer (and dropped it because it was the digital gain register, burned into the CR2).

After the CMOS/ADTG analysis, my first suspect would be the white level register from ShootSsDevelop ( https://www.dropbox.com/sh/onppbwy44fqomxa/P75rs6pgTW ), obvious from the aperture graphs, but I'm too lazy to try it right now :D

edit: extending this, it would be effectively a post deflicker on the JPEG output (not just on XMP metadata).

edit2: tried, don't works

Audionut

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Re: Sticky LCD exposure correction for ettr shots?
« Reply #2 on: February 17, 2014, 08:35:37 PM »
I've modified the underexposure zebra point, to my own personal judgement of accepted noise in the shadows.
I've attempted to make this into a menu option, but alas, my coding skills aren't quite there yet.
It would also be handy to have half zebras at user limits, and full zebras at stdev.  Like the functionality of zebras in the highlights of dual_iso.


Raw based histograms don't lie, JPG based previews often do.

a1ex

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Re: Sticky LCD exposure correction for ettr shots?
« Reply #3 on: February 17, 2014, 08:39:51 PM »
Yep, thought the same about underexposure zebras. Right now they are at 1 EV of SNR.

I'm afraid half zebras won't work as well on dark areas because of the noise, but a different color (light gray?) should do the trick.

Audionut

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Re: Sticky LCD exposure correction for ettr shots?
« Reply #4 on: February 17, 2014, 08:43:42 PM »
Light grey is a good choice  :)

Transparency of the overlay from user set point to the currently defined point would be great.  This way we can still see the detail.

a1ex

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Re: Sticky LCD exposure correction for ettr shots?
« Reply #5 on: February 17, 2014, 08:49:44 PM »
Well, on new cameras there is a transparent gray predefined in Canon palette. On older ones, there is only transparent black, but I believe the gray one can be faked without much trouble.