Jump to content

NLCbanner2024.jpg.2478be509670e60c2d6efd04834b8b47.jpg

Using a dual band filter with a mono camera


tomato

Recommended Posts

Apologies if this notion has been discussed before and I missed it, but is it possible to use a dual band filter designed for a OSC camera with a mono camera?
I presume it would produce a NB “luminance” channel made up of combined Ha and OIII signal. Could this then be combined with data from a dual band/OSC camera to produce a NB colour image?
Not as efficient as separate NB filters and a mono camera, but worth a try?

Link to comment
Share on other sites

How would you distinguish between OIII and Ha in the mono capture? You'd get them both but in one channel. If you used this as a luminance channel the Ha and OIII would be applied equally to all three channels, destroying any colour differentiation.

Olly

  • Like 1
Link to comment
Share on other sites

Yes, and I think that it is most suitable use for dual and tri band filters - as a luminance for NB images.

Say you have Ha/OIII dual band filter - then, all you need to shoot is:

1. OIII

2. Dual band filter

Spend more time on OIII if it is fainter of the two (and usually it is). Use Dual band filter as luminance.

Use OIII data as teal component of chrominance and Dual band - OIII as Ha or red component of bicolor image. Just make sure that you have matched exposure lengths for 1 and 2 so you can easily subtract the two. Do subtraction after background removal phase while data is still linear.

Link to comment
Share on other sites

I just read the original post - and sure, if you already have OSC+dual band for color - just shooting dual band + mono for luminance is excellent option.

It will give you by far the best SNR per unit time of all combinations (much like lum filter does for LRGB).

  • Thanks 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.