What Celestial Objects That Are Suitable To Capture Under MoonLight? [Deep Sky] Processing techniques · Szijártó Áron · ... · 3 · 207 · 0

The Moon is great to capture under moonlight. Planets also ;-)

For deep sky objects, it depends. The brighter the Moon, the brighter the part of the sky that *should* be black. And that means less contrast, which makes it really hard to see faint things. And can add a nasty gradient across your image.

For stars and star clusters you generally want to capture the colours, so you want the full visual spectrum of light. Which means no filter or a UV/IR cut filter. Those also show you the light pollution from the Moon, though. If your field of view is not too wide and the cluster is bright, you will probably get away with this. Best way to be sure is to test!

If you insist on imaging other things when the Moon is up and bright, your best bet is to use a filter, which means picking a target that emits light that you can pick out using a filter. In practice that's generally either hydrogen alpha Ha or oxygen [OIII].

Which means your targets should be *emission* nebulae, and probably only the relatively bright ones at that. I would not bother trying galaxies when the Moon bright. Their cores are also faint. Just not *as* faint as their outer regions.

Tobiasz:
I would say that you should only bother with narrowband and/or star clusters while the moon is up but I am also the first one going against those "rules". Shoot what you like. When I was doing my first light with my mono setup and LRGB I kept shooting because the weather was good for several nights. Did I shoot a star cluster? Hell no, I shot the very faint IC356 and it was fun. Moon phase was 86% on average. See here
My Pleiades and M13 was also shot while full moon, so it works.


It is not perfect by any means, but it shows the detail I wished for so I am happy. I expected way worse for almost full moon.

It's interesting to note that shooting at galaxies while the moon is up can be both unlikely and somewhat possible. When I attempted this, the moon was nearly at its first quarter, and visually, it didn't completely wash out the sky. My target was the Sombrero Galaxy. At one point during my observation under the moonlight, I started to notice some strange shadows. I'm not sure what caused them, but when I activated my Seastars LP filter—my only telescope at the moment—those shadows disappeared.