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Narrowband Issues

Filters Acquisition Auto-Focusing Narrowband Deep Sky
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Mossyback avatar
Mossyback avatar
I decided to expand my astrophotography into narrowband imaging. My budget has allowed me to get three 5nm filters. Last night I tried out the H-Alpha filter using N.I.N.A. and immediately ran into a couple of problems.

Autofocus is not working well. I’m using Hocus Focus. What adjustments should I make to it as it works well with LRGB?

ASTAP also gave my problems so I’m assuming this is related to the exposure times used by both these programs.

What settings should I be using? 

Hank
Tony Gondola avatar
Tony Gondola avatar
You have the right idea, Ha cuts out a lot of light from the stars as you've probably noticed. You need to increase the exposure time for both solving and focus. That assumes you're not using a filter wheel. If you are, NINA can switch to the L filter for both tasks so no changes would be needed. On way or the other you'll need to figure out the right values for your setup. I generally use 15 sec. for solving and 5 sec. for focus but your mileage may vary…
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Sam Badcock avatar
Sam Badcock avatar
I could not for the life of me get ASTAP to work with my SHO and LRGB filters as it just wanted to debayer them everytime despite all setting relating to this being turned off!! 

For a plate solver I use PlateSolve3.8 from PlaneWave!! It’s free and works bloody well and only a tiny fraction slower than ASTAP so maybe give that one a whirl

Now for focus I use Hocus Focus as well and have no troubles with focusing with NB filters!! Are you sure you have enough exposure time and gain for it to do its thing?? Cuiv has a video on the tube where he shows you how to setup a mini pc with NINA etc etc and there’s a section in there where he shows you the settings he uses for focusing with an EAF!! I’ve copied these and have no troubles, I also run my focus exposures at 2 or 3 seconds from memory with 0 offset (haven’t calculated this yet)

When I get home I can copy my focus settings here if you would like and I’ll try find the link for PlateSolve3.8 for ya shortly
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Tony Gondola avatar
Tony Gondola avatar
Sam Badcock:
I could not for the life of me get ASTAP to work with my SHO and LRGB filters as it just wanted to debayer them everytime despite all setting relating to this being turned off!! 

For a plate solver I use PlateSolve3.8 from PlaneWave!! It’s free and works bloody well and only a tiny fraction slower than ASTAP so maybe give that one a whirl

Now for focus I use Hocus Focus as well and have no troubles with focusing with NB filters!! Are you sure you have enough exposure time and gain for it to do its thing?? Cuiv has a video on the tube where he shows you how to setup a mini pc with NINA etc etc and there’s a section in there where he shows you the settings he uses for focusing with an EAF!! I’ve copied these and have no troubles, I also run my focus exposures at 2 or 3 seconds from memory with 0 offset (haven’t calculated this yet)

When I get home I can copy my focus settings here if you would like and I’ll try find the link for PlateSolve3.8 for ya shortly

+1 on PlateSolve 3, I use that as my primary solver and ASTAP as the backup.
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Mossyback avatar
Mossyback avatar
Thanks folks. This is very helpful.

Hank