Adding true color onto dual-band OSC data - Forums

Topic starter

Apr 28, 2023

I've taken several images using a OSC camera (533MC-Pro) and a dual-band filter. I have the L-Enhance, but it'll soon be getting a new home as the NBZ just arrived.

My only complaint about dual-band filters is the star colors. I'd like truer star colors, and the thought had occurred to me, "why not shoot some subs with just a UV/IR-cut to restore star colors?

But the question is how long and how many subs?

To simplify matters, suppose I get 3-hours worth of 5-minute subs (36 x 300-sec) of dual-band using the NBZ.

What should I then shoot w/o the NBZ filter to restore star colors in terms of # subs and sub lengths?

Clear Skies,
Phil

Well Written Engaging

Joon Ren

Apr 28, 2023

Stars don't require long integration times to get decent SNR. 30-60 mins of RGB data should be more than enough. I've seen people go as low as 15 minutes although this was per filter shooting mono. Regarding exposure times, 30 sec to 1 min subs to avoid blowing out the cores and losing color.

Helpful

andrea tasselli

Frequent contributor

Apr 28, 2023 · Edited: Apr 28, 2023

Phil Creed:
I've taken several images using a OSC camera (533MC-Pro) and a dual-band filter. I have the L-Enhance, but it'll soon be getting a new home as the NBZ just arrived.

My only complaint about dual-band filters is the star colors. I'd like truer star colors, and the thought had occurred to me, "why not shoot some subs with just a UV/IR-cut to restore star colors?

But the question is how long and how many subs?

To simplify matters, suppose I get 3-hours worth of 5-minute subs (36 x 300-sec) of dual-band using the NBZ.

What should I then shoot w/o the NBZ filter to restore star colors in terms of # subs and sub lengths?

Clear Skies,
Phil

Ideally the same ADU per star in both filters but practically you can get away with much less, I'd say down to 1/10th of the overall exposure with the NB.

Dale Penkala

Apr 28, 2023 · Edited: Apr 28, 2023

Phil Creed:
I've taken several images using a OSC camera (533MC-Pro) and a dual-band filter. I have the L-Enhance, but it'll soon be getting a new home as the NBZ just arrived.

My only complaint about dual-band filters is the star colors. I'd like truer star colors, and the thought had occurred to me, "why not shoot some subs with just a UV/IR-cut to restore star colors?

But the question is how long and how many subs?

To simplify matters, suppose I get 3-hours worth of 5-minute subs (36 x 300-sec) of dual-band using the NBZ.

What should I then shoot w/o the NBZ filter to restore star colors in terms of # subs and sub lengths?

Clear Skies,
Phil

Hello Phil,
I agree with both responses. I always use my NB filters to gather the data on the object then shoot with and IR/Cut or L-Pro and pull the stars out after the SPCC for color accuracy and add the layer back in PM to the starless image.

And yes I’ll go as short as an hours worth of data for star colors. 30s subs.

Dale

Helpful

Tom Boyd

Apr 28, 2023

Using a 294mc, and LeNhance or Askar NB filters, I typically shoot 30 minutes of 30 second UVIR (sometimes L-Pro) subs, dithered every sub to combine with my NB data.

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