Attached is 2 images from the same data set.
300 of 30 sec. (Next time I will try 60 sec.)
Gain setting of 288. (Next time I will reduce that to 150.)
The first image is un cropped and basic post processing ie:
Background Neutralisation, SCNR (remove green), Colour Calibration and then a Histogram Stretch.
It reveals a very bad SNR (Signal to Noise Ratio) and there is no colour.
Probably because of my settings (above).
The secound image (same data):
Not a single pixel was left standing...
I threw at it every PI processing tool that would do something to help.
It certainly pays to get things right at the start :-(
By tilting my screen to what seems a strange angle not only your image has come alive but all the images in the deep space section, that I have looked at again with this extreme tilt in the screen, just look much better.
How silly of me not to have realised the importance of screen tilt and its effect on an image.
alex
Pkay,
Your second image is a clear standout with some nice detail in the silver coin. I was scouring through my images yesterday and reprocessed(Startools) believe it or not a shot I took of this object on a very warm mid October evening in my backyard. 20 min total. Your right in saying getting good data is key and stretching images with poor S/N ratio means somethings got to give. I have to increase the black point in order to rid the noise whilst boosting the colour. Its a fine balance but more subs in clearer skies would account for this anytime.
Anyhow my "two cents worth.
Melb Cup today- typical cloud cover but not stopping the beer and BBQ!
Pkay,
Some astrophotographers use auto focusers and this is the way to go however like you I'm still learning the ropes too. My Newtonian has been modified to enable photography and the setup isn't ideal. I find zooming in on the canon live view helps prior to locking it in. Sure atmospherics vary the focus during the session but not enough to bother me too much. I take 25-40" subs and even though the star roundness isn't perfect it can be remedied. Shorter exposures certainly help retain star colour rather than overexposing through longer subs. It's all trial and error, I find plenty of error but hey every new trick goes into the melting pot.
These are great ! Could people put up the scope/camera/mount (if they can remember), integration time and maybe software. Even if it's just brief. Would help guide doofs like me.
The first NGC253 pic is one from 2014.
13 X 15second subs, equal amount of darks at iso 3200, canon 1100d, 10"f4.7 newt, no guiding, stacked in DSS. Tracked using an old 1970's cave mount RA drive only(second pic).
The second 253 pic is from October this year. Same scope but now on a Heq5 pro mount and guided with a finder guider, zwo120mc and Phd2, a stack of 19 x 2min subs @ iso 800, canon 1100d, Baader coma corrector added, stacked with DSS and processed with PS cs5.
.
. The recent ones processed in PI. Earlier PS or direct stacking with Envisage.
