M42 Full Moon Test with 585mc

[WolfieGlos]

Naturally last night we had perfectly clear skies coupled with a 93% Moon, so it seemed like a good chance for a test session.

I decided to take apart the imaging train and try for some star clusters and a stab at Planetary with the 102ED again. Just after I finished looking at Jupiter, I noticed Orion was well placed with my scope, so I removed the barlow and decided to try for the Trapezium cluster.

This is 400x10s subs at gain 252 with the 102ED at it's native f/7, with the 585mc with uv/ir cut. Stacked without darks, but with 30 flats+darkflats. No crop to this image.

We all know the nebula is a very bright target, but I'm surprised just how well it came out for just over an hour of exposure, given the near Full Moon, with the colour and detail. It's only a quick job processed in Siril and I've probably pushed the data a bit hard with the noise coming through (and using some wavelets for sharpening), but overall....very surprised. I might try again tonight if the clouds allow it.

Edited November 25, 2023 by WolfieGlos

[Space Cowboy]

Very nice! Yet to try my 585 on dso but very impressed by your result!

[WolfieGlos]

1 hour ago, Space Cowboy said:

Very nice! Yet to try my 585 on dso but very impressed by your result!

Thanks Stuart! I've tried it once so far using my 72ED, but it produced a lot of blue fringing on the stars.

First time trying it on the 102ED and I'm really happy with the result, definitely going to try it on others too. Also intending to pair it with a 200mm f/2.8 lens which would give a nice widefield view.

[ollypenrice]

It's very good, no question.

But it is also, by a mile, the brightest DSO in the sky. When I last imaged M42 I used 11 second subs for this, the Trapezium region, and 15 minute subs for the outer nebulosity. That gives an idea of just how bright the Trapezium is.

Olly

[WolfieGlos]

53 minutes ago, ollypenrice said:

It's very good, no question.

But it is also, by a mile, the brightest DSO in the sky. When I last imaged M42 I used 11 second subs for this, the Trapezium region, and 15 minute subs for the outer nebulosity. That gives an idea of just how bright the Trapezium is.

Olly

Thank you Olly 🙂

Totally agree with the brightness of M42, I was more surprised that it picked up the detail and colour with the very bright Moon nearby, which was contrary to what you read online a lot.

15 minute subs? Wow, what scope was that with? Not the Rasa surely? 

[ollypenrice]

7 minutes ago, WolfieGlos said:

Thank you Olly 🙂

Totally agree with the brightness of M42, I was more surprised that it picked up the detail and colour with the very bright Moon nearby, which was contrary to what you read online a lot.

15 minute subs? Wow, what scope was that with? Not the Rasa surely? 

Not the RASA, no. Tak FSQ106 with an Atik 11 meg at 3.5"PP - so a lot of light per pixel but only 50% QE.

Olly

[WolfieGlos]

23 minutes ago, ollypenrice said:

Not the RASA, no. Tak FSQ106 with an Atik 11 meg at 3.5"PP - so a lot of light per pixel but only 50% QE.

Olly

Haha, I bet that would have been somewhat overexposed at F2…

I did try 10 minute subs a few years ago and ended up with horrible walking noise, perhaps a symptom of a DSLR. Not tried it since, I think the longest I’ve done is 6mins. Maybe I’ll try it with the 585mc when I get some clear skies and no moon. 

[ollypenrice]

11 hours ago, WolfieGlos said:

Haha, I bet that would have been somewhat overexposed at F2…

I did try 10 minute subs a few years ago and ended up with horrible walking noise, perhaps a symptom of a DSLR. Not tried it since, I think the longest I’ve done is 6mins. Maybe I’ll try it with the 585mc when I get some clear skies and no moon. 

Long subs are strictly for cooled cameras. My standard narrowband sub with that rig was of 30 minutes.

Olly

[Elp]

I did try it at F2 when I had the related 485mc, 1s for core was still too much, 10s for outer parts. Mine was pretty non detailed though as I only spent around 10m on it, yours is excellent. Need to try it again this season but Dec is a busy telescope time, still got projects I started years ago to finish.

[WolfieGlos]

Thanks Elp. Hopefully the weather plays ball and you can finish those projects. Currently our forecast is terrible.