View Full Version here: : First light Lagoon
Crushellon
28-08-2016, 04:25 AM
Got my new rig running last night. A lot of learning for me, pretty much an entirely new experience going from a DSLR with a f5 newt to a mono CCD with an RC8. I had a bit of an issue with the binned colour images showing a tail on the larger stars so I ended up having to do 360sec 1x1 colour shots (I attached a crop of the stars if anyone knows what it is)
Also my first post outside of the beginner forums, be gentle lol
I didn't do any processing other that calibration and image integration. I will have a go at deconvolution and other things when I can get the time
Overall quite happy, I seem to be able to push the guiding a lot harder with this setup. I could only ever get 2mins with the newt. I will be happy when I sort out the binned image issue so I can push up my Luminance times.
19 x 120sec Lum 1x1
4 x 360sec R 1x1
4 x 360sec G 1x1
2 x 360sec B 1x1
Hi res: http://www.astrobin.com/full/261555/B/
atalas
28-08-2016, 07:05 AM
Congrats on the new gear and on first light Tim....your off to good start.
Atmos
28-08-2016, 11:30 AM
Some great detail Tim and nicely resolved. You haven't even burnt out the hourglass at the centre of the lagoon!
RickS
28-08-2016, 05:04 PM
That's really nice, Tim!
The "tail" is horizontal blooming caused by what is arguably a design fault in the KAF-8300 sensor. It has a horizontal shift register that's not deep enough to contain 2x2 pixels worth of data. One solution is to turn down the gain if you have the option to do that. A better solution, IMHO, is not to bin in the camera because the KAF-8300 doesn't do it very well anyway. You can always bin in software later on...
Cheers,
Rick
Crushellon
28-08-2016, 05:31 PM
i can't change the gain with the 8300 and apt. So does that mean I could capture all my subs at the same length and just do software binning in pixinsight on my rgb images to bring them up to the same level as my luminance subs? Or am I just better off doing 3x the exposure time on my rgb?
RickS
28-08-2016, 06:20 PM
I'd just take the RGB data unbinned (maybe do the subs a bit longer than the Lum) and then do some noise reduction on the combined colour data before you add the Lum. You can beat up the colour quite a lot and still get a great image if you have good detail in the Lum.
atalas
28-08-2016, 06:20 PM
That's interesting Rick....what, just the Sbig cameras do that?I've never seen anything like that in my Microline and I've done lots of 2x2 binning.
Does look like blooming though.....bit of a bummer.
RickS
28-08-2016, 06:24 PM
Hi Louie,
It's a "feature" of the KAF-8300 chip. Some camera vendors get around it by reducing the gain. My SX camera showed this problem and the suggested solution was to adjust a trim pot on the PCB to reduce the gain. QSI 583/683 cameras have a low gain mode that you're supposed to turn on when you're binning. Not sure how FLI handle it but perhaps they tweak the gain automatically depending on the binning mode?
Cheers,
Rick.
atalas
28-08-2016, 06:28 PM
Ah,ok thanks for the info Rick....glad I don't have that problem with ML8300.
Crushellon
29-08-2016, 02:17 PM
Had a go at processing. Also updated the hi res link.
Atmos
29-08-2016, 02:56 PM
Certainly a lot punchier now Tim :thumbsup:
In some ways I actually prefer the subtleties of the original. I think my personal taste lies somewhere between A and B :P
multiweb
04-09-2016, 08:53 AM
I like the repro. Nailed the focus on that one. Very cool. :thumbsup:
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