IIRC the reason that people play around with custom camera profiles in lightroom or photoshop is
because their white balance sliders don't go far enough to get things into the correct range.
There's no such problem in darktable, so the process is drastically simpler.
For example, here's a basic process using those Adobe tools that you might use as the basis for
developing a workflow in darktable:
https://photographylife.com/how-to-process-infrared-photographs
Here's what I've come up with:
Open the channel mixer module.
* Pull down the destination dropdown list, and select blue
* Right click on the blue slider and type "0"
* Right click on the red slider and type "1"
You have now put the information from the red channel into the blue channel.
* Pull down the destination dropdown list, and select red
* Right click on the red slider and type "0"
* Right click on the blue slider and type "1"
You have now put the information from the blue channel into the red channel.
Now open the white balance module. I guess the idea here is to play with things until you get what
you want, whether that be a white ground and blue sky or slightly red ground or whatever. There's
no right or wrong answer. One technique that seems to work for me is to use the spot white balance
and select some foliage, like leaves or grass on the image. That'll get you in the right ballpark.
Then play around with the sliders or try selecting different parts of the image until you get the
colours that you want. Or try selecting different things within the image with the spot white
balance tool until it looks good.
Next, you'll probably need to go into the exposure module and play with the black and white points,
and then you might want to use the equalizer to increase the contrast, and then perhaps color zones
or color correction (again keeping in mind that red and blue have been reversed).
HTH,
Rob
On 03/06/16 14:41, Raymundo Vega wrote:
It may be user ignorance/error, i tried channel mixer playing with values
there, but i was not
able to swap (for instance) blue and red channels like the color profile bgr do.
~rv
"Obscurity is a far greater threat than piracy"
Tim O'Reilly
On Thu, Jun 2, 2016 at 3:59 AM, Robert William Hutton <[email protected]
<mailto:[email protected]>> wrote:
On 02/06/16 20:52, Tobias Ellinghaus wrote:
On Thursday 19 May 2016 10:33:47 Raymundo Vega wrote:
Hello all,
I am playing with infra red photography and need pointers on how to
create icc files, i like to try different channel mixtures.
I am not aware of any easy to use editor for ICC profiles. What I
personally
would do is patching the sources of darktable
(src/common/colorspaces.c) to
create the profile you want and then have it written to disk. But that
requires
some basic programming knowledge. Maybe someone else has a better idea?
Well, infrared photography generally involves using a really extreme white
balance and/or
switching the red and blue channels. Can't you just do that using the
white balance and channel
mixer modules? No icc required. I was going to do a video on it at one
point, but having a
baby has kinda crimped my free time.
Regards,
Rob
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