Question: Luminance and a OSC Camera

[Grifflin]

If I already have around 6 hours of integration time using a dual narrow band filter (L-Extreme) and I have the opportunity to take another 6 hours in one night (no moon), would I be better to continue with the filter OR use no filter apart from the UV/IR cut on the camera and combine as a sort of LRGB?

Neil

[Guest]

I would say it depends on the target.  You can definitely use the no filter data as the Lum along with the narrowband data and the rgb from the no filter for the stars.  But some targets benefit more from the narrowband data (think color separation) as the rgb data may not show enough contrast between the two narrowband channels.  You'll still get the narrowband colors in the image, just the contrast will be more "muddy".  Narrowband is really good at creating good contrast between the different bands. 

 

This is just my personal opinion from fairly limited experience on some difficult targets I have tried to image before in rgb alone (like sh2-274), then revisited using narrowband and trying different combinations of rgb and narrowband data.  On some targets, using rgb as lum works just fine.  Best way to judge is look on astrobin and see good examples of your target shot with lum and narrowband and without.

 

Edited March 5 by dciobota

[Grifflin]

Thank you.  Yep, that makes sense.  The target I was imaging earlier was the Christmas Tree cluster.  Good point about using Astrobin though.