8 Tips for Better Astro Images in Heavy Light Pollution

In this video, I explain some of the techniques I've used to improve my images from Bortle 7 - 9 skies. I present some acquisition tips as well as some pre and post processing ideas that help minimize background gradients and improve overall detail and contrast.
My website: www.ancientphotonsastro.com/
Instagram:@ancient.photons
Blog: www.ancientphotonsastro.com/blog
0:00 Intro
1:19 More Integration Time
2:56 Pick Reasonable Targets
4:42 Horizon Discipline
6:10 Shorten Sub-exposures
7:40 Dual-band Filters for OSC
9:15 Go Mono!
11:41 Use Local Normalization
14:37 Background Extraction
16:35 Final Thoughts

[@bengterlandsson7921]

Great tips will need to re-watch the video prior to next reprocessing session. Thanks

[@AmatureAstronomer]

Good advice. Just subscribed.

[@anata5127]

Very good. No fuss, no nonsense presentation of truth. I could see that you know intricate details, experimented. I agree with every word. I do even shorter exposures.

[@ancientphotonsastrophotogr6999]

Thanks Ana - I appreciate it. Yeah, no point in pushing subs too hard in LP - especially if your seeing conditions aren't great. Thanks again for the note, and clear skies to you.

[@anata5127]

@@ancientphotonsastrophotogr6999 I image with 9.25 Edge no reducer, bortle 7-8, image scale 0.4”/pixel; so highly oversampling. I still get routinely 2-2.5” FWHM. I follow rules that you listed. I could add that choice of telescope could be important too. I don’t know it as yet. Recently, I also started to experiment with lucky imaging (1-15 sec per frame). Let’s see what will happen.

[@ancientphotonsastrophotogr6999]

Good point about the telescope choice. I tried some broadband imaging with my hyperstar (f/2) from bortle 8/9, and subs were basically blown out in 20-30 seconds. So maybe slower is a bit better in heavy LP, as with your Edge 9.25. I'll be interested to see how your lucky imaging goes. It's tempting to get a larger, faster newt or even dob to try out some lucky deep sky imaging.

[@anata5127]

@@ancientphotonsastrophotogr6999 Yeh, I am looking forward to see results. I have refractor (Vixen 103mm f7.7) as well. I will try on both. I have no fast scope. Fastest is refractor with reducer F5.

[@StevenSSmith]

Thank you for sharing your wealth of information I'm looking forward to the next video

[@DB2023Space]

Great info Chad. I've been out of it for several months but finding my way back the past couple of weeks. Home grounds are about a Bortle 7ish or maybe 8. It's great for testing gear, techniques, etc but I found a nice area that's about a 4 and I actually look forward to the 1hr15min trip. Most normal folks would 😳 when you them you image from the graveyard or cemetery, but I love it. There's never anyone there after dark, people that drive by on the country road (very seldom) can't see myself or the gear. This particular cemetery has about 1/3 of the northern area "unpopulated" so I'm not actually anywhere near those that are resting. Hate batteries, I run everything with a small generator that just idles all night long on less than a gallon of gas. Your M51 edit video was well done also. I will have to revisit that once home with PI up and running. I have a question that might help others starting out with LRGB and even SHO imaging. Once you have the individual masters in mono, how do you combine them into a single color image? Do you have a session detailing or explaining the basic steps? Again, great job and thank you for taking the time to produce your presentations.

[@ancientphotonsastrophotogr6999]

Thanks Dan - imaging at a cemetery sounds creepy - but also a clever idea since no one will bother you there and there's typically lots of open space. So to combine LRGB or SHO masters, there are lots of options in Pixinsight. There's actually an "LRGBcombination" process that makes it pretty simple for LRGB - but I usually combine RGB first, then add a fully-edited luminance (using the same tool). Other tools include "ChannelCombination" for RGB (or straight SHO), and of course Pixelmath. Pixelmath is the best option for combining SHO masters because you can really experiment with various combination in each channel to refine your pallete. Anyway - you're right, maybe a video demonstrating the various combination tools in Pixinsight would be useful.

[@danbartlett7923]

Very helpful! Especially appreciate your tips for LN and your DBE setting of 10 in PI. Cheers, Dan

[@OigresZevahc]

Great advice, I’m a novice and understood fully. Also, your tips on achieving backfocus on the EDGE8 were a life saver.

[@ancientphotonsastrophotogr6999]

Glad to hear it Sergio. Hope your Edge 8 is working out for you. It's a great scope!

[@viewintospace]

Very good tips and very well done video!!!!

[@ancientphotonsastrophotogr6999]

Thank you! Just subbed to your channel - good stuff!

[@GarnettLeary]

Nice video. Keep it up

[@martrich1098]

This is a great summary and extremely useful for those of us doing it the hard way. Thanks for the tips, you have done a good job of persuading me to think about a mono camera and filters setup - I've always avoided it due to added complexity of the setup, but maybe I just have to bite that bullet.

[@ancientphotonsastrophotogr6999]

You won't regret it! It's a bit more work, but mono imaging really gets you to the next level IMO.

[@GediAstro]

Great tips! I live in a Bortle 8-9 white zone. Unfortunately I don't use Pixinsight just yet but will probably migrate to that soon enough :)

[@ancientphotonsastrophotogr6999]

You can't go wrong with Pixinsight! It's an investment of time and money, but the tools are amazing for astro. Thanks for checking out the video!

[@naegeleh]

Thanks! I learned a lot!!!

[@shubinternet]

So, I’m curious to know what you think about some of the other PixInsight tools, like GraXpert, the *Xterminator line from RC Astro, etc….

[@shubinternet]

Also, for your Luminance layer, how do you calculate how much time you should spend on capturing that layer versus the others? What about the narrowband layers? For the Luminance layer, do you use a broadband UV/IR cut filter, or nothing at all?

[@j.s.3407]

So was the reason you moved to mono the width of the dual-narrow band filters? Today, you can get 3.5nm +-0.5nm dual narrow band filters. Player One Anti-Halo and the Altair 4nm OIII/SII filter. Does you advise to move to mono hold with these new filters?

[@fleischpflanzerlmitsenf]

I use 10s for Luminance in bortle 8. N.I.N.A. Has an exposure plugin which you can prime with your Sharpcap sensor analysis. It tells me 7s. I use increments of 10 since this is how i built my dark library

[@mikehardy8247]

I made a major upgrade 6 months ago, by going from DSLR and lenses to ZWO ASIAIR, ASI533MC PRO on a 360 mm doublet, EAF, AUTO GUIDER. Modest, but awsome SW SA GTI. I'm in bortle 8-9. Which filters specifically, and you said 2 minute subs? No plans to do Pixinsight any time soon, and screw Adobe's subscription!

[@mikeharden7904]

Good video. Good basic reminders. I'm still using OSC (ASI294MC Pro) as I thought it would be faster in the beginning. But I now realise that the mono gathers more data in a shorter period so OSC not so fast after all 😁. The mono camera plus 3.5nm filters is a sizable investment. Guess I'll have to save my pennies and make the plunge soon.

[@ancientphotonsastrophotogr6999]

I was surprised by how much more efficient mono was when I made the switch. I still think OSC can be useful from a dark sky, though, when you have very limited time. But from home, mono has been a real game-changer for me. It is crazy how big of an investment it is to get a filter wheel, 3nm filters, and a good mono camera! I suppose it's a whole new level of commitment to the hobby.

[@McF182]

Great video, Chad! Question about DBE. Seems pretty straight forward when you apply DBE to a galaxy photo, but what do you do when you are trying to extract the background of a nebula that takes up the entire image? How do you pick you sample points?

[@ancientphotonsastrophotogr6999]

Thanks Brandon, I appreciate it. Good question - if I have a gradient on a nebula photo (which is usually narrowband), I place samples all over, avoiding stars and the brightest parts of the target. It try to balance the samples over the entire image, so there's not an abundance of them on one section. If it's a crowded star field, you can remove stars in the linear phase using StarX, then run a DBE. That'll give you more room for samples - and you can make them larger. Afterwards, add the stars back in.

[@McF182]

@@ancientphotonsastrophotogr6999 got it! Thanks!

[@zijadzikedzehovic6206]

Finally found.

[@mikeharden7904]

So just priced my same camera in mono and Optolong's 3nm SHO filters at $2200. I already have the filter wheel so that price is doable. Thanks

[@ancientphotonsastrophotogr6999]

Not bad at all!

[@crashmaxx1987]

Good tips! I actually haven't heard most of these. You could work on how you add music. Harsh transitions, kind of loud. Not great

[@ancientphotonsastrophotogr6999]

Thanks for the feedback @Crashmaxx, I'll work on smoothing out my music transitions. Still working on my video chops!