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Comment by verandaguy | Hacker News Reader

    > astrophotographers do not use cameras with UV-IR cut filters at all

I'll be pedantic here and say that the author's probably talking to people who use DSLRs with adapter rings for telescopes. I've been interested in doing this for a while (just unable to financially justify it), and I think this is actually something people in this niche do.

Then there are things like the Nikon D810A, which remove the UV-IR filter from the factory (but IIRC retain the Bayer filter).

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My recommendation, as someone who started with a DSLR and then modded it to remove the UV-IR filter, I would have been better to just skip to a beginner cooled mono astrophotography camera, like the ASI533MM Pro. It is night and day difference in terms of quality and roughly the same cost and it automates better much better.

A high end DSLR is a huge waste of money in astrophotography. Spend the same amount on a dedicated astrophotography camera and you’ll do much better.

How do you recover colour from a mono astro camera? Just run it for 3 exposures behind a gel of each of the R/G/B colours, then comp?

Yes, and you would almost certainly want to automate it with a filter wheel that changes the filters for you on a schedule. However, a key advantage of a mono camera is that you don't have to limit yourself to RGB filters. You can use some other set of filters better suited for the object you are capturing and map them back to RGB in software. This is most commonly done with narrowband filters for Hydrogen, Sulfur and Oxygen which allow you to see more detail in many deep space objects and cut out most of the light pollution that would otherwise get in your way.

> How do you recover colour from a mono astro camera? Just run it for 3 exposures behind a gel of each of the R/G/B colours, then comp?

Essentially yes. To get faint details in astrophotography, you actually will capture a series of images of each filter with long exposure times like 3 minutes per capture with a total capture time per filter measured in hours. You then star align everything, then you integrate the captures for each filter into a single frame to remove noise and boost signal, then you comp them together.

> It is night and day difference

Particularly high praise in astronomy!

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