Deep Sky Photography at a Moonlit Night

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Last week we had a couple of beautiful winter days with reasonably clear nights. Unfortunately, it was almost full moon with the moon lit to 80-90%. However, with the enthusiasm that is typical for beginners I didn’t want to use the night exclusively to test equipment - I wanted to get a few pictures as well. 

Star clusters are an object type that I used to observe visually at such nights as they are usually reasonably bright and have good contrast. So that ist what I try first. 

NGC457, The Owl cluster
30x10sec, C9. 25 with reducer 1/6.3, ASI 294MC Pro on EQ6-R Pro

M35 (right) with NGC 2158 (left)
30x10sec, C9. 25 with reducer 1/6.3, ASI 294MC Pro on EQ6-R Pro

I think these came out quite nice. With so much moonlight it is hard to take longer exposures to get deeper. However, the brighter stars are starting to saturate anyhow, so these settings are probably ok.

Most deep sky objects are looking way more impressive on a photograph than visually. However, while I like the pictures, this probably not really true for star clusters. So I am turning to more challenging objects.

I knew that imaging objects with lower contrast will be very hard without a filter. So I got an Optolong L-eXtreme dual narrowband filter. This filter passes only wavelengths of the Ha and OIII spectral lines, that are typical for many nebulas.

M76, Little Dumbbell Nebula 
30x60sec, C9. 25 with reducer 1/6.3, Optolong L-eXtreme filter
ASI 294MC Pro on EQ6-R Pro

NGC 2359 , Thor‘s Helmet
40x120sec, C9. 25 with reducer 1/6.3, Optolong L-eXtreme filter
ASI 294MC Pro on EQ6-R Pro


The pictures are basically directly taken from the color camera without separate composing of the individual channels. I just did a standard photometric color correction in Siril to obtain the colors. 

I am really impressed with these first results.  Particularly Thor’s Helmet came out really nice, especially keeping in mind that the image was taken at almost full moon.








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