Waveform histogram & luts?

Software darktable
1

Hello, i am new here, i hope i posted in the right place.

I like a lot the waveform histogram, i was wondering if there is any way to make the grey more opaque because i cannot see proper the histogram, i rather see it more contrasted or so…

Also, wanted to ask if someone knows if is possible to use luts with this amazing software or of there is any planing for that?

I am using windows, and mac (less now because seems i cannot get it to work with opencl)

Thank you
Sebastian

2

Yes, there is a Color Look-Up table module; it isn’t listed by default.

3

care to tell me please list it? i am using windows

4

Hi @nongrata23 & Welcome!

See here About the new Color checker LUT module in DT
… here https://discuss.pixls.us/search?q=dtstyle%20order%3Alatest
… and here https://discuss.pixls.us/search?q=haldclut%20order%3Alatest

Have fun!
Claes in Lund, Sweden

5

Hi, thank you for answering,

What i meant, it is possible with this software to load personal luts? (there are alot of cinematic luts and other fx that u can do with them).

Any ideea how could i increase the contrast of the histogram display?

Regards

6

There‘s a way to convert common 3dLUTs as used for e.g. FCP by converting a it8 chart picture and a version with applied LUT to a darktable style using darktable-chart ( see https://www.darktable.org/usermanual/en/darktable_chart.html )
for example:
It8Target:
http://www.colorreference.de/testdata/printscale5.tif
it8.cht file is available within argyllcms download
https://www.darktable.org/usermanual/en/darktable_chart_making_input_images.html describes how to prepare the files for darktable-chart.

7
8

Hello, Thank you for answearing…

I manage to do the process but the results are different that as intend.

I did the following:

  • I alterated the “printscale5.tif” with a lut, saved it as printescale5lut.tif
  • now as i saw in the manual you are supposed to provide a raw image (not a tif), anyway i did it with the tif, but i cannot select the standard input profile because is a tif, so i have srgb.
  • did export as per intructions pfm with lab profile (other settings left as default from export module)
  • i did the same also for the original tif printscale5.tif

next
opened darktable-chart

  • i selected printscalelut.pfm (generated from dartable with srgb and prf-lab color applied), right after i did add the it8.cht to aling the patches, next
    -reference values, i selected the rendered pfm file (printscale.pfg) (i wonder if i did a mistake here, maybe should be another reference file that i should load, not generated by me with dt)
  • process 33 patches (gray ramp i did with with both), export
  • i imported the style

but when i apply it, the effect is not the same, so something i do wrong but i don`t know exactly what :slight_smile:

anyway this is a great way convert luts, maybe we can make a database of styles with comon type of luts

Thank you

Sebastian

9

After understanding more the process i think i also need the cie file of the it8, do you know where i can find it?

10

i understood now, we need a good target digital version of any kidn that has mode then 200 patches, with cie adn cth files, anybody has something like this? and i think we can transform corectly cube lutes like this

11

as the source isnt a raw file, you have to use only the tone curve and color look up table steps of the generated style.

12

yes i got that, but for the reference i need another file it8.cie which i don`t have, do u know where i can find it?