Two Triangles

[DaveS]

Two completely different images of Fleming's Triangle, but which is better? And does the [NII] bring anything to the table?

This one was made in 2017 with the 130 apo, 0.75x reducer and Trius 694 with 6 hours in NHO from Bortle 8 Ruislip                This was made last month, 130 apo, TS flattener, ASI 1500 12 hours in SHO from Bortle 4 / 3 Dorset. 3 nm Astrodons and 10 min subs in each case

 

This wa processed in AstroArt 5                                                                                                                                                       This was AstroArt 7

No other processing.

[MarkAR]

Both great images, can't really say about the Nii making any difference.

[Gina]

I agree.  You can see the difference but is the one with NII actually better?  I think not.  And this confirms what I found with the whole Cygnus loop - the amount of NII is negligible and the bi-colour image is good.

[don4l]

I cannot see that the NII makes any difference either.

I did an experiment the other night with some data that I have on the Crescent area.  I subtracted a 3nmHa from a 7nm.  The result was inconclusive.  There were no fine structures at all, and the result could have been the result of different data stretches, or even slight flat field differences.

As an aside, last year I did an image of the Veil with 1 hour of Ha and 2 hours OIII - expecting the OIII to be much weaker.  This year, I have taken another 2 hours Ha, but I haven't been able to improve the image at all.  The Ha on it's own does look better, so this might be a processing issue.

[DaveS]

Thanks for the replies, I waited rather than replying to each post.

I wasn't sure at first so wanted some independent assessments, but I'm coming to agree that [NII} doesn't bring anything to this,and in fact may just be recording the HII bleedthrough from the overlap of the passbands.

At least it means I won't be wasting my time or drive space haring after illusory data.

[DaveS]

After looking at the two images side by side I think I prefer the new version as the colours look more subtle, less "in-yer-face", I think the resolution is better too.