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Widefield imaging in Bortle 6 sky versus Bortle 4?

16 Oct, 2019 13:33
Hi there,

Due to health issues I am no longer able to take the long drive out of town to my Bortle 4 sky location and now must settle for a Bortle 6 location near my home. I had a guided EQ mount, but now I have just a Star Adventurer tracker and will be doing only widefield astrophotography. I love inter-stellar dust and hope to image targets like M45 to California nebula, Orion and surroundings, etc., and be able to show lots of space dust. I use an unmodified Nikon D5500 but have been able to get great colours and detail when I had enough total integration. I use Pixinsight and Photoshop and I'm not too bad at post processing so if the subtle dust and details are in the raw image I can usually tease them out fairly well.

1. At this new Bortle 6 location will I be able to match or come close to my previous imaging results, especially when it comes to revealing dust?
2. Will this simply be a matter of adding more integration time by increasing the length of subs and/or shooting more subs?
3. Anything else I should know or do in order to optimize my results from the Bortle 6 site?

Thanks very much,
Edited 16 Oct, 2019 13:34
16 Oct, 2019 18:18
Hello Rudy.
Use LPF filters.
You may need to have higher iso.
Best Regards.
16 Oct, 2019 20:16
Hello Rudy,

I hope you get better soon and enjoy again your darker skies!
Till then, you can plan to image objects near your local zenith using a longer focal length. And since you are a PixInsight user, master well the Dynamic Background Extraction (DBE) process. I image from Bortle 5 skies. When imaging below 45° local altitude, most of my processing time is spent on DBE. Above 45° and during dry and transparent nights, I may be lucky and get away with a pass of a low-order Automatic Background Extraction process smile

Don't give up!
17 Oct, 2019 01:57
It is going to take a lot more time, or use a faster scope/lens. The difference from 4 to 6 is very large.
17 Oct, 2019 11:46
If you are coming from Bortle 4 you will find this new situation quite annoying and just checking your gallery, you wont be able to keep the same quality.

According to my needs and few years experiences under Bortle  7 and 4,
- RGB imaging works for me over SQM 20 with LPS filters and near to 21 and above w/o filters
- Between SQM 17-20 I use only  NB with a mono camera or maybe UHC, semi-UHC close to SQM 20.

You can check your place on the SQM map or measure it yourself.
Edited 17 Oct, 2019 11:55
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