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View Full Version here: : NGC6744 - 2nd image from that night - 10 inch testing


SimmoW
03-08-2017, 09:57 PM
22 shots of 2 minutes each @ISO3200 taken with the Sony A7s collector's item (sans star-eater feature) and the Royce 10 inch mirror.

HIGH REZ HERE (https://www.flickr.com/photos/48232585@N00/36212258231/)

I have calculated the optimum sky limited exposure for this Heathcote sourced image and yes 2 mins is the correct exposure time. Gawd! But I still feel I might try some longer exposures another time to see what extra I can retrieve.

I've compared the image to a few here and am very pleased with the result, considering my remaining improvements yet to be made to the system. Especially fine tuning of the back focus and guiding. Oh and elec focus about to come into play.

This image means a lot to me, as it was the point at which the below started happening, I typed this on one of Mike's image posts, It was when I truly fell into the abyss...........Later, when I plate solved all the faint fuzzies, it was even more of a buzz!

"I have to mention my 'religious' experience last weekend. First full decent test of my 10 inch scope. At 3 in the morning at sub zero Heathcote, I was hunting around the planetarium for good targets. Fell across the Fornax region, so started aiming for various areas there. No specific target searches, just took a 20sec image (with the sensitive A7s), plate solved and peered. And peered! I ended up taking an hour to compose my shot and loved every freaking second of it! Enthralling, mystical, searching for those incredibly massive and populous galaxies. I could feel myself succumbing to the aperture and focal length bug! No.....dont order the RC Simon!!!! Well not yet anyway."

gregbradley
03-08-2017, 10:13 PM
Crazy good for such low exposure time. This is a dim galaxy. A bit too much red though. Its mostly bluish with a yellowish core and some Ha in the arms.

Imagine if you did 10 hours worth The rise of CMOS sensors eh?
Whilst CCD development is all but finished CMOS are becoming amazing.

Greg.

cometcatcher
03-08-2017, 10:33 PM
Yep, amazing for 44 minutes.

Atmos
03-08-2017, 11:18 PM
I can attest to how cold Heathcote has been recently and you've done a good job with such a faint sucker. 44 minutes isn't a lot for this one, as Gregsays, hit it hard with a good 10 hours :P

SimmoW
04-08-2017, 01:10 PM
Thanks folks, your reactions are making me satisfied that the idiosyncrasies of the cam are worth enduring. At least until a decent sized Sony mono chip is available.

I just saw the new release of Pixinsight notice, so will give the easily named "PhotometricColorCalibration" a whirl on the colour balance.

Placidus
04-08-2017, 04:25 PM
Well done! The field came out very nicely too. That's a good focal length for this galaxy.

Andy01
04-08-2017, 08:51 PM
Looking good Simmo!
Um, the stars around the galaxy are sharp, but all the rest appear soft, not sure what's going on there :question:
Pretty nice setup you've got going, looking forward to seeing results when it's fully pimped up ;)

RickS
04-08-2017, 09:38 PM
You need a huge scope, Simon. Don't let anybody tell you different ;)

That's excellent for a short integration with a DSLR. NGC6744 is a challenge even for CCDs and bug scopes.

Cheers,
Rick.

LewisM
07-08-2017, 08:41 PM
OI! Wotz wrong with 80mm? :P

VERY nice resolution there Simon!