Wipe woes

[Mike in Rancho]

Thanks Ivo, more stuff to think about!

Thank you for confirming that; the dataset has already been archived in my "wipe test" folder.

Sweet! My gradients will be (in)famous.

If shot under substantially similar circumstances, you should be able to use Wipe in one go, without having to apply it separately.

I always try that first before resorting to pre-Wipes. One, it's extra work; and two, I'm not sure at what stage it's okay to be feeding ST only 16-bit data. Maybe if I skip Wipe on the recombine not a problem? The image "seems" okay, though I do bin a lot.

But a lot of times there seems to be one or two filters I feel need something different. OIII. Or perhaps L versus something like R alone.

It may be less of an issue when going forward with the backed-off Uncal1 that worked well here, as opposed to what I had been doing which was high aggression Basic. And with the L file, that was 97%. The RGB's were about 95%, and the LRGB processed through fair enough even so. But applying that 97% to the Ha, as opposed to NB preset, was just too much of a discrepancy and I could not get a blend I was happy with in NB Accent.

For the most recent M78 that I liked, I used Uncal1 aggression/falloff of 75/50 for L, and then 60/50 for RGB, with NB preset for the Ha (but I did change the edge behavior to absorb 50). The L needs Uncal1 75/50 I think, and the RGB would probably survive that with minimal difference, but the Ha, while close, didn't seem quite right with Grow Opposite turned on - and I was losing some (admittedly faint) structure particularly in the lower right.

If some sort of normalization was performed already (either a previous Wipe or something else), Wipe would indeed not be strictly necessary to achieve good coloring (the important thing for coloring is that something is done to remove any channel bias).

Ooh, I have a question about that! Does the color channel bias thingy still work when I have run totally independent Wipes on my R, G, and B filter files? To my untrained mind, normalization usually means something is being compared, such as having the three channels concurrently in Wipe's sights due to OSC or composited RGB.

That certainly looks very nice; lovely contrast between the blue reflection and red Ha! It's very cool that these sorts of shots are possible from such a light polluted area - no one would be the wiser how much you "suffered" to get to this image!

Thanks. It took a while for me to finally get to that LRGBHa M78 I was pleased with. My M78 post (does not include the subs) folder is 136GB. Might be a record for me.

But other than that, which on the good side led to a lot of learning, I wouldn't call it suffering. These are the only skies I know! And it's not like downtown LA or Tokyo or anything. The darkest spot I can point to, zenith-north, is at the borderline of B7 to B8. I'll measure it again on a good dark night and see what I can get in ASTAP. And I'll check out my Orion-zone to the south also, where M78 and so many other targets reside, just to see what we were looking at here - though it seems to vary even across my FOV.

Just wait until it's time for me to try Omega Centauri or Cent A again.