two separate images from dual-iso shot?

Started by moonlite, September 10, 2014, 10:20:00 AM

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moonlite

hi! i´m really in to manually merging my hdr-shots, and i´d like to do that with dual-iso shots, too.

i would like to have one image that is purely the higher iso image and one which is purely the lower iso image. is there any way to accomplish this?

thanks

Audionut

Dual ISO is dual line interlaced, instead of the traditional single line interlacing.

http://www.magiclantern.fm/forum/index.php?topic=12012.0

a1ex

Develop the DNG at two different exposures (say 0 EV and +4 EV for ISO 100/1600), then merge the jpeg's.

This script automates the task, but it usually picks more than two exposures: www.magiclantern.fm/forum/index.php?topic=7022

moonlite

yes, my problem is that extra information is picked up from the other image. this in my experience manifests itself as extra noise. so no tool can just give me the images completely separately?

a1ex

Octave, compiled with 16-bit GraphicsMagick:


octave:1> system("dcraw -4 -E DUAL1234.CR2")
octave:2> im = imread("DUAL1234.pgm")
octave:3> a = im(1:4:end, :);
octave:4> b = im(2:4:end, :);
octave:5> c = im(3:4:end, :);
octave:6> d = im(4:4:end, :);


Or, cr2hdr --debug-blend, but the data you get from there is useful only for visual inspection, not for manual blending.