dt inverted ellipse mask question/issue?

Software darktable
1

Following the manual recommendations, I am trying to use the exposure module for a subtle vignette.

But using the exposure module with inverted-ellipse mask seemed to affect the center “unmasked” area.

To diagnose…

  • I made a plain white wall photo TIFF and imported.
  • I added one exposure to boost the base level. You can see the color picker values in the center.
  • I added a second exposure with the inverted-ellipse mask. You can see the color picker values in the center.
  • I took two screen captures with different exposure module setting (EV -2.0), and (EV -0.33)

Base
Base3566×2382 1.24 MB

EV-20
EV-203566×2382 2.26 MB

EV-033
EV-0333566×2382 1.97 MB

Unsurprisingly the center darkening scales with the exposure setting, so looks like the mask is not truly zero/off within the inverted solid shape/boundary. I don’t know enough about the code and history to know if this rises to the level of a bug or is some accommodation for good results in other situations.

Any suggestions welcome.

Screenshot 2023-04-27 at 12.13.03
Screenshot 2023-04-27 at 12.13.031546×552 52.6 KB

2

Can not reproduce. Are you sure you haven’t accidentally somehow decreased opacity in the mask manager?
grafik

Would you share your tiff and xmp including the mask?

3

I don’t think I see any change… putting 2 samples…one inside and one out…toggle the module with the mask inverted and the values match??

4

@apostel338 found the source of my issue, raising mask manager opacity from 90.1% to 100% fixed it.

All new shape masks default to 90.1% in the mask manager. Not sure if the is that by design or there is something wrong with my install? My build is 4.2.1 official macOS ARM build.

Would be great if someone could confirm either way. Thx

5

You probably adjusted it with the mouse wheel. Its easy to do but I don’t remember how to do it.

6

Setting opacity before drawing a shape sets the default… so scroll to 100 and draw a shape and the default will be set to 100 for all new shapes… any others can be corrected by scrolling on them…

I should be more clear…go in any module and select a drawn mask…just pick a circle but before placing it …ctrl scroll the opacity then place it… this will set the current default for new drawn masks until you change it…

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7

Thanks for your help Todd. Your procedure sorted the sticky 90% issue out. Thx

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