Dual ISO - massive dynamic range improvement (dual_iso.mo)

Started by a1ex, July 16, 2013, 06:33:50 PM

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a1ex

Quote from: Marsu42 on October 02, 2013, 12:20:55 PM
Is cr2hdr considered "production-ready" now, or are there outstanding important bugfixes or enhancements?

I've processed roughly 2000 pics with it, and for testing I have a directory with 50 difficult shots (most of which were taken from this thread).

Known issue: the night fire shots from jOt. I've outlined a robust formula for autodetection, which relies on comparing 4 histograms, only need some time to implement it and run the tests.

So, now it's up to you to try it and upload the CR2 files that fail to convert or have major issues (hint for @artiswar).

artiswar



1%

QuoteI recently suggested an option to embed them in the dng for safekeeping & easy updating with a newer cr2hdr

I keep them around in case there is a better CR2hdr released and I might want to reprocess the shots. The DNGs are already 2x the size of the cr2 files.

Marsu42

Quote from: 1% on October 03, 2013, 12:23:05 AM
I keep them around in case there is a better CR2hdr released and I might want to reprocess the shots.

Embedding the cr2 in the dng would allow a seamless in-place update with a newer cr2hdr, keeping the tags and file location: http://www.magiclantern.fm/forum/index.php?topic=8336.0

Quote from: 1% on October 03, 2013, 12:23:05 AM
The DNGs are already 2x the size of the cr2 files.

No, they aren't, it's just that ml's dcraw process doesn't output a proper dng - if you (losslessly of course) recompress the dual_iso dng with ACR like in Lightroom, the size is cut by half.

artiswar

@1%

Dying for a fix here. Very integral shots that need to be processed. Or if there's a way to deinterlace without processing ISOs that would be fine too. I just need the shots. Thanks so much.

1%

Well I was stumbling around looking for a newer build of cr2hdr.exe I tried all the 9/27 I found... your "cr2" looks fucked up... lines in the shadows.

http://www.filedropper.com/oldx-cr2hdr

My old self compiled from 9/5 did this:

artiswar

@1%

You're a potential lifesaver. Anyway to run this in the Mac environment? Or fix my CR2?

1%

VM or wine or (parallels?) it was made on win7 x64 but should be ok on any windows environment..

artiswar

Quote from: 1% on October 03, 2013, 03:57:10 AM
VM or wine or (parallels?) it was made on win7 x64 but should be ok on any windows environment..

Any reason why I'd get a console window in Windows when trying to convert? Sorry for all the questions.

1%


artiswar


Audionut

Open a command prompt manually and process the CR2.  This way you will see the error message before the prompt auto closes.

a.d.

Quote from: 1% on October 03, 2013, 03:42:38 AM
Well I was stumbling around looking for a newer build of cr2hdr.exe I tried all the 9/27 I found... your "cr2" looks fucked up... lines in the shadows.
...
I notice the same thing ... It broke up between 13 and 20 September

a1ex

Solved.

If you notice these things, post a CR2 that shows  the problem, I can't read your minds ;)

delorossa

Where can i change in MLn dual Iso??? I cant see nothing?

Marsu42

Quote from: a1ex on October 02, 2013, 04:02:22 PM
I've processed roughly 2000 pics with it, and for testing I have a directory with 50 difficult shots (most of which were taken from this thread).

Are there any specifics we should watch out for in our dual_iso shots? My shots look just fine, but then again I don't really know what type of problem(s) to look for @100% crop.

Question: The help says 100/1600 is too high, but it looks great on the 6D. is the +4ev spacing warning there because the higher iso has more noise (i.e. worse on crop than ff), or because a large spacing might confuse cr2hdr for reasons other than iso noise?

Edit: Also you might want to add some version tag to cr2hdr, or with so many binaries floating around it might get confusing sooner or later with what version a cr2 was converted?

a1ex

ISO 100/800 will most likely look the same in shadows, with less aliasing in highlights. Plus, in video mode, I don't have black correction info, and 100/1600 or higher will do a lot of nasty things to black level.

The latest problematic CR2 had exactly this issue, so... had artiswar followed the indications from the menu, he wouldn't have had this issue.

Look at raw zebras; if you get weak zebras over important detail, it's likely to have aliasing there.

Marsu42

Quote from: a1ex on October 03, 2013, 08:59:54 PMlus, in video mode, I don't have black correction info, and 100/1600 or higher will do a lot of nasty things to black level.

To clarify again: this is only a problem for video, photo mode is more likely to work ok with 100/1600, correct?

Quote from: a1ex on October 03, 2013, 08:59:54 PMlus, in video mode, I Look at raw zebras; if you get weak zebras over important detail, it's likely to have aliasing there.

Thanks!

a1ex

Yes, the warning in photo mode should appear at 3200 on most cameras. On 5D2/500D/50D it appears at 1600, because this is the max analog ISO there.

akumiszcza

I've downloaded cr2hdr.zip from OP today (I don't know when it was updated) and found out dcraw.exe included there requires cygwin1.dll installed, which might be an issue sometimes. Previously it shipped with a standalone version (200k bigger). Reverting back to previously included dcraw.exe works fine I think (I hope no new dcraw.exe features are required?)

1%

Depends on the camera.. .Ie 6D/5DIII/M old dcraw might cause issues.

Rai2121

I just want to give a huge thanks to everyone working on Dual ISO. I decided to test it out in the video function and here is a quick sampling of it. There are definite circumstances where it really shines and looks quite good in video form. I think it looks pretty good in the first 3 shots. The last shot was really just to see how much dynamic range I could get. All were shot 100/3200, so that maybe the problem with the chroma artifacts in the last shot. I've learned that if a shadow is right next to a highlight, there can be issues. I am really excited to continue to see which scenarios it looks the best in.

a1ex

Next time, try following the advice from the menu (100/800). The noise improvement from 800 to 3200 is less than 1 stop, but the difference in aliased areas is 2 stops. The improvement from 1600 to 3200 is close to 0 (but for that you pay 1 full stop of aliased data).

swinxx

@alex
do you also prefer 100/800 when shooting a low light scenario?

i have read somewhere that 1. we should ettr the scene and then 2. apply the second iso for raising the shadows..
so this could also be 800/1600.

am i right? 
thx sw