RCC Request for Feedback and Honest Critique of my M16 (Pixinsight User)

Yes, Neon, that’s the perfect word for it.

I did use IntergerResample X2 because I used the Celestron C9.25 with an IMX585 (2.9-microns) camera.

The pixel scale was originally 0.61”/px but then improved to 12.2”/px (0.61 X 2) . After IntergerResample, I did crop heavy because I had different framings from different sessions that didn’t overlap perfectly. Maybe that had something to do with it.

Thanks!

Tommy

Tommy Mastro · May 17, 2026, 07:19 PM

Yes, Neon, that’s the perfect word for it.

I did use IntergerResample X2 because I used the Celestron C9.25 with an IMX585 (2.9-microns) camera.

The pixel scale was originally 0.61”/px but then improved to 12.2”/px (0.61 X 2) . After IntergerResample, I did crop heavy because I had different framings from different sessions that didn’t overlap perfectly. Maybe that had something to do with it.

Thanks!

Tommy

I don’t know what your seeing is like but I shoot at 0.66” all the time with a 585. I’d love to see a version at the original plate scale.

andrea tasselli · May 17, 2026, 07:35 PM

Your black point is too high, hiding significant nebulosity for dubious gains in contrast. Needless to say the colours are waaaaaaaaaaaaaay too garish for my tastes but there you go…

“Garish” - great word for it.

Regarding the black point, do you think it’s from the way I stretched? Or perhaps too strong with the contrast curves in CurvesTrasnsformation? Or a combination of both.

Plus I used DarkStrutureEnhance.

Tommy Mastro · May 17, 2026, 08:59 PM

Tony Gondola · May 17, 2026, 07:49 PM

Tommy Mastro · May 17, 2026, 07:19 PM

I don’t know what your seeing is like but I shoot at 0.66” all the time with a 585. I’d love to see a version at the original plate scale.

I’m in a Bortle 5/6 with average to slightly under-average seeing most nights. When you shoot at 0.66”/px your image doesn’t look overly-smooth (loss of detail)?

I have noticed when I use the IntergerResample, it reduces the noise noticeably.

Not really, I’m in Oklahoma under B8 skies. In fact, I’ve been doing a lot of images lately at 0.33” arcsec/pixel. I can’t get away with that plate scale on really rough nights but most nights are usable. Of course that might just be the result of an aperture of 150mm compared to 55mm.

Willem Jan Drijfhout · May 20, 2026 at 07:24 PM

Regarding the stars, how do you add them to the SHO starless image? Just adding?

Assuming you put them together towards the end in a non-linear state, you need to ‘screen’ them into the final image. You can use a PixelMath expression for it, or easier and with more control use the ImageBlend script from CosmicPhotons. And use Screen for the blending mode.

You don’t need much RGB data if it’s just for the stars, so you probably have enough data. If the problem is not in the screening, the issue could be with the stretching. It is easy to overstretch a stars-only image, resulting in complete lack of colour. Two suggestions for stretching the stars-only image:

-Star Stretch script from Seti-Astro

-MultiscaleAdaptiveStretch (default PI tool). Set target background to lowest value allowed (I believe 0.001) and turn on Colour Saturation at a pretty high value.

Sorry, just seeing this. I do unscreen and rescreen stars using Lukimatico’s short cuts. And I love SETI Astro’s statistical stretch and star stretch. Someone on here dogged the SetiAstro suite but I like them and don’t see any negatives effects.