Digital Astronomical Sketching

I own a 150mm dobsonian reflector telescope at home (Looks like a canon) and I wanted to know if anyone here has ever heard about astronomical sketching. When astrophotography is not a viable option for an amateur astronomer who wants to capture what he sees through his telescope in an image, he may decide to make a sketch of what he sees through his telescope on a pad of paper. Due to the risk of potentially blinding out night vision, red light is used to illuminate the paper when sketching an image seen through a telescope. The image may either be drawn as a negative on white paper with a pencil and later inverted in an image editing program or the image may be drawn on black paper with a white pencil on site.

I have been wondering if it is feasible to use Krita on a tablet computer to sketch images seen through a telescope on screen. My major concern would be risking losing one’s night vision when staring at a bright computer monitor. This risk could be reduced by using a custom “night vision” theme that displays all color as red and by creating the image in grayscale when working outside. I myself have not done much astronomical sketching other than sketches of bright planets and the moon, but I have read several articles on this topic in Astronomy monthly magazine covering this topic. Mostly, the authors for these articles use physical drawing media other than for inverting the color of negative drawings, but it might be possible to use Krita for astronomical sketching with some tweaking.

I can’t find any sketches I have made in the past so I will share a link to a YouTube video explaining the process:
https://m.youtube.com/watch?v=QDC3R39AcSA&feature=youtu.be

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Hey! I built myself a dobsonian telescope some time ago and tried some astronomical sketching, but never really got into it. I never thought about trying it in Krita, even thought it sounds like a very good idea. All the things Jeremy Perez shows in his video should also work in Krita (at least in theory), and especially the assistant tools could make life a lot easier. Unfortunately I don’t own a tablet computer, so I would have to take my laptop onto my balcony.

KDE has a built-in theme editor, and since Krita is a KDE app, it is possible to use those themes in Krita. I may try to make a red “night vision” theme and share it here. The best workaround for the canvas is probably to make a red fill layer on top of the layer stack and switch the blending mode to “multiply”.

What do you think about it?

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You’re not alone in not having a tablet PC or pen display. My current graphics tablet is a 12 year old Wacom Bamboo Fun CTE-450. The small tablet is fine when working at the computer inside, but I’ll eventually need to buy a tablet PC or a pen display monitor if I want to comfortably make astronomical sketches outside.

A red night vision theme would definitely be useful in using Krita outside at night next to a telescope. Both of my sky atlas apps on my phone include a night vision mode to make the programs easier to use at night without severely affecting night vision.

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Hi! Here is a screenshot of a first attempt to make a Night Vision theme for Krita. It is still pretty WIP, some areas are still lacking of contrast and I don’t know if the dark red background is a good idea. Unfortunately, things like color selector, the canvas border and the icons are not affected by the theme. I haven’t tested it yet so we will see if this is a problem.


The Image that I used in the screenshot was just a little test to see if the workaround with the red fill jayer in multiply mode would work :slightly_smiling_face:

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I wonder if there is a way to get gray scale to display as red color. So far the results look promising.

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