First, Thank you so much.

I was following the photographylife.com tutorial, but stopped when i tried
the channel mixer to move blue to red and green and set the blue to red
plus green minus blue.

Thanks again, my test photo looks much better now in false color and BW.

~raymundo

"Obscurity is a far greater threat than piracy"
Tim O'Reilly

On Thu, Jun 2, 2016 at 11:29 PM, Robert William Hutton <[email protected]>
wrote:

> 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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>>
>>
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