H-Alpha filters for color CCD camera

[menardre]

Frank

I have only tried this once. I took a few hours of Heart Nebula with the IDAS NB1 filter attached to ZWO ASI071 one-shot color camera. On another night I took a few hours of same object and same setup but without the Nebula filter. When I process the individual sets of images it is obvious that the predominant color is red. The image from the IDAS NB1 filter is really nice since it cuts out mostly everything else (so this is great to do when there is sky glow from the moon). The non-IDAS master also shows a lot of detail. Adding the two enhances the reds.

I then tried to convert the IDAS image to green via selecting a different debayer. This causes an interesting effect- the Heart nebula was a combination of red and green. I am still playing with the images since there are several different ways of combining (average, additive, etc) which gives slightly different results. I have not found what I consider the 'idea' combination settings. I will let you know when I complete my tests.

Roger

[bluemax]

Thanks Roger. It's great you are experimenting with this and I look forward to any results. Thanks for the effort.

[NGC7000]

Interesting research, Roger. I'll be very interested in your outcomes along with Frank.

I just bit the bullet and ordered one of these:

https://agenaastro.com/optolong-2-l-enh ... ilter.html

I have been extremely limited with my use of the Nikon D5300 because they don't ( or no longer) make a clip-in H- alpha filter for anything less than full frame Nikon sensors. I was going to buy a 2" Ha filter, but then saw this. I was also going to spring for the 7nm L-Extreme filter, but realized a very important potential shortcoming one might have with extremely (~7nm) narrow wavelength filters and that is:

You can't see anything until you take a picture. Depending on the sensitivity of your DSLR sensor, you may not be able to frame your target. This is NOT a problem if you are doing live view on a computer screen. However, if I am using my Canon T3i on it's own, and relying on the camera liveview, I generally cannot focus on anything less than a bright planet or the moon ( occasionally a bright star) when using my 12nm Atronomik Ha Filter. So, I can't imagine what it would be like with 7nm in the field without a computer and liveview.

Just thought I'd throw this option out there to add to the confusion, Frank. Have a nice day.

Tom

[bluemax]

Nice Tom! I would be happy to test out your new filter in anytime. Could run all sorts of imaging and let you know how they come out. Seriously, I am very interested in what you find with this filter. Especially what you said about finding a target with it. Maybe you have to find it without the filter then insert it into the scope.

[NGC7000]

Maybe you have to find it without the filter then insert it into the scope.

And then you'd have to refocus something you can't see without the filter. ENHHHH!

[bluemax]

It never ends, does it

[NGC7000]

Were it only Astronomy.

[Pete]

Hey Frank,

The IDAS LIGHT POLLUTION SUPPRESSION (LPS) FILTER blocks light pollution while retaining color.

Pricy, but you'd expect it would be for all the bandpass trickery.

https://optcorp.com/products/idas-light ... b66d4786b8