SharpCap Forums

Captured 16th & 19th November 2025. Processed as HOO, SHO, Ha - 7.8h integration for the SHO image.

HOO - Ha 15x450s, OIII 30x450s
SHO - SII 18x450s, Ha 15x450s, OIII 30x450s
Ha 15x450s
Equipment: Vixen 81s refractor, Celestron AVX mount, Vixen 0.67x reducer/flattener, Atik 314L+, Atik EFW2 9-slot filter wheel, Altair Ha (7nm), OIII (6.5nm), SII 6.5nm) filters, QHY miniguider.
Software: SharpCap, Pixinsight (Starnet++, NarrowbandNormalisation & StarReducer scripts).
Data: SII 18x450s, Ha 15x450s, OIII 30x450s; bias 100; darks 50, flats 50 each filter.
Capture: dithering used (3 pixels every frame with 10s settling time).

The exposures came from Brian's (@oopfan) minimum exposure calculations and are 1.5X minimum exposure. No over-saturated stars were observed. See viewtopic.php?t=9054

The frames were processed using drizzle_2x. This enabled the under sampled optics (camera has 6.45µm pixels, scope/reducer is F5.5) to deliver a pixel scale of 1.55 arcsec/pixel rather than a pixel scale of 3.11 arcsec/pixel thus avoiding 'square stars'.

The last couple of days have been spent in PixInsight experimenting with workflows to reduce noise - very much a work in progress.

As always, more data would improve the images.

Dave

Thanks for the hat tip, Dave. You've become a bona fide expert at PixInsight!

Also a shout out to ChatGPT (aka R2D2) with its guidance on dither/drizzle.

Brian

Thanks Brian. Not expert, just struggling at a different level.

The colours were balanced straight from the ChannelCombination - no need to torture any pixels. This is the histogram on Astrobin:

I need more data to overcome the background noise in the fainter areas. I am reluctant to apply more contrast or adjust the black point as the result ends up 'too black'.

I just need to work out how to get good prints, as currently they come out too dark - maybe the AI has the answer?



Dave

Hello Dave,
Have you by any chance tried Seti Astro Suite.
It does a great job on noisy images.
I'm just a new comer to imaging (couple of years)
and have found that Seti Astro suite has improved
my end result by at least 50%.
Thought I would pass that on just in case your interested.
All the best
George.

George

Thanks for the tip, I will look into the Suite.

Dave

Vesmaobs261 wrote: Sun Nov 23, 2025 10:18 am Hello Dave,
Have you by any chance tried Seti Astro Suite.
It does a great job on noisy images.
I'm just a new comer to imaging (couple of years)
and have found that Seti Astro suite has improved
my end result by at least 50%.
Thought I would pass that on just in case your interested.
All the best
George.

George I am in the exact same boat as you are. I do miss my Siril but SASPro simple kills it and does anything you can want...

Randall

Hi Randall,
My jaw dropped at the result that SASPro delivered after I loaded. a noisy and
hard to clean up image, though I must say that I have not played around with
other software that may or may not give the same result.
All the images I take I process with the said software and not once have I been
disappointed in the output, providing you get your settings correct, but that
comes with trial and error, or as they say, a learning curve.
Enclosed find the image that made my jaw drop...noisy and denoised.
Regards
George

Vesmaobs261 wrote: Mon Nov 24, 2025 10:27 am Hi Randall,
My jaw dropped at the result that SASPro delivered after I loaded. a noisy and
hard to clean up image, though I must say that I have not played around with
other software that may or may not give the same result.
All the images I take I process with the said software and not once have I been
disappointed in the output, providing you get your settings correct, but that
comes with trial and error, or as they say, a learning curve.
Enclosed find the image that made my jaw drop...noisy and denoised.
Regards
George

I have not tried PI but I hear the learning curve on SASPro is similarly as rough as PI.

Randall

For the time being I'll be sticking with SASPro as it
does all I need to do without too much fuss.
Its functions are pretty straight forward without getting
too complicated or confusing.
All the best in your imaging endeavors.
George

George, Randall

I have been looking at the SetiAstro site, particularly PixInsight scripts. The Statistical Stretch script looks particularly interesting. It looks like a load of grisly PixelMath expressions are hidden behind a civilised front end. I will be giving this script a workout as I am hoping to obtain some more Tadpole data tonight.

Thanks for the heads up.

Dave