can the ocular eyepiece simulate brightness and contrast?

[fommil]

Hi all, I have all my oculars, sensors, lenses and telescopes entered into stellarium and I absolutely love it, it is so useful to be able to simulate the FoVs and to get an idea of what to look for.

But something I find myself doing a lot is taking a screenshot of an ocular view and the editing it in GIMP to reduce the brightness (and increase the contrast a little) to make it look a bit more like what I actually see. It's not super scientific, it's just for sharing with friends to give them realistic expectations of what they might see. Am I missing a trick, is there maybe an option to do this fully within stellarium? (ArchLinux, latest version on aur is 24.4)

Search for previous questions brought up nothing particularly obvious: https://github.com/Stellarium/stellarium/discussions?discussions_q=ocular+brightness

[gzotti]

The User Guide describes the setting "Auto-limit stellar magnitudes". We can model things when models exist. Object appearance has many factors like environmental light, light pollution, age, experience, ... which we currently have no model for, and thus no visible settings.

[fommil]

a simple and very rough model, taking two parameters, could be to take a brightness and contrast value provided by the user. That's all I'm doing in GIMP and it works incredibly well. It doesn't have to be overly scientific to set realistic expectations.

From the guide, for completeness:

Auto-limit stellar magnitude sets the magnitude limitation for stars based on telescope diameter. When disabled, the main program’s setting applies (see section 4.4.1). Note that two manual limits for ocular view and main program are handled, and switching between ocular and main view also switches those values.

but it still looks like ~hours of total exposure time, not anything that can be realistically expected through an eyepiece.

[fommil]

Incase anybody else wants to do this manually, this is the ffmpeg command I use to convert screen shots of the ocular view into something that attempts to set realistic expectations for friends and family of what to expect to see through my telescope:

ffmpeg -i input.png  -vf "hue=s=0,eq=brightness=-0.4:contrast=1.0" output.png

brightness can be from -1 to 1, contrast can be from 0 to 2 (it's just using defaults here)