ASI1600MM HH Luminance

DJScotty (Scott) · #1 26-09-2016, 06:57 PM

Well, it's technically not Luminance per se, more shot through the CLS filter, but essentially the same thing.

These are 30 second subs, approximately 360 of them.(About 3 hours of data).
Camera was at Unity gain.
Shot through my Sigma 150-500mm lens at 500mm (f6?)
Some gentle sharpening and contrast enhancement and noise reduction, all courtesy of Astra Image.

Experiment (when the clouds disappear): drop the gain to its lowest and see how far I can push the subs. I tried 3 minute subs through the red channel the other night at Unity gain. It was a grey screen with a few white dots. Not good at all.

The only thing is the 4 hours my laptop took to process the 360 images today in DSS. Hopefully my i7 16GB RAM tower in the office will do it a bit quicker!

Anyway, thanks for looking and C&C welcomed.

Scott

Slawomir (Suavi) · #2 26-09-2016, 07:15 PM

Great to see you are having fun with your new camera Scott

The light patterns around Alnitak are quite hypnotising, and the image has an overall mysterious feeling to it. I would rather have the nebulosities somehow brighter though.

RickS (Rick) · #3 26-09-2016, 07:31 PM

Hi Scotty,

As Suavi said the neb is pretty faint. I wonder if you could have stretched it a bit further? Still better than any Horsehead that I've ever done

Cheers,
Rick.

DJScotty (Scott) · #4 26-09-2016, 08:00 PM

Thanks gentlemen.
Yeah finally i am having fun rather than fighting with equipment.
Probably could be stretched more. Just using the default result with fits liberator.
And Rick thanks. Obviously you have never shot the horsehead before

glend (Glen) · #5 26-09-2016, 08:27 PM

Scott there should be much more there than is showing up. Even shooting those short subs you have enough for a better result. The CLS filter passes Ha, so the 'meat' of the Horse should be buried in there. If you can supply a file i will have a go at it with Photoshop CC. Have a look at Atmos recent Horsehead with very little data, or mine with about an hour of Ha. Its in there imho.

Atmos (Colin) · #6 26-09-2016, 08:51 PM

I do wonder if it is simply because it is through a CLS filter and not an actual narrowband. If the skies aren't dark then it may just be a lack of contrast. Having never attempted it with a Lum filter, not sure. Looks like some clean data anyway

Slawomir (Suavi) · #7 26-09-2016, 09:13 PM

Quote:

Originally Posted by DJScotty

Thanks gentlemen.
Yeah finally i am having fun rather than fighting with equipment.
Probably could be stretched more. Just using the default result with fits liberator.
And Rick thanks. Obviously you have never shot the horsehead before

Awesome news you are having fun Scott. I know too well how frustrating this hobby can be at times...

As for the histogram, you can easily adjust black and white points in Fits Liberator and then pick / modify a function that further stretches the fainter signal. We look forward to many revisions of this photo, maybe even in colour?