How do you rate this for noise.

[xelasnave]

I am in Sydney for this.
I though I would see if I could pick up any dust lanes which should be in the top left of the photo but zip..The Jewell Box and the other star was just to position things..
Anyways I thought I would make some sort of attempt at dittering at first rying to follow a pattern 1 2 3 thing between each capture and the not so much maybe move it some where off patten further ..so it was all over the place.
I did not get anything in the way od dust lanes but I thought I would ask how you rate the noise in this capture. It is straight from DDS and in there I morved all sliders a little left to darken it cause it was new white as stacked.

Gear..80mm triplet, eq6 unguided except for moving to try and effect a dither. 80 frames at 1600 iso at 30 seconds eack. nikon d5500 unmod.
I purposely did not include dark frames or bias ... how good bad do you think the noise is here?
alex

[xelasnave]

You can notice the dust lane but nothing to write home about.
alex

[Mickoid]

Alex, for minimal processing, I'd rate your result for noise as good. It looks fine to me and you even have some nice star colours coming through on your first post. :thumbsup:

[xelasnave]

I thought it wasnt too bad.
The fella I saw on utube said he didnt use darks after dithering ...he was also on for simple processing as he called it by using camera raw in photo shop...I bought it but it doesnt have what his one had...
Alex

[JA]

^ Tony Hallas, eh?

.... and a nice smooth image re the noise and colour!

Best
JA

[LewisM]

The problem is Alex, in 30 sec subs, the cam is not really going to build up much heat from keeping shutter open etc etc. A LOT of the noise in DSLR's for astro comes from the heat from long exposure.

40 minutes of short subs isn't going to show much either compared to 40 mins of say 5 min subs, let alone say 10 min subs. I live in a horrid deep red zone, and I not only shoot unfiltered, with an OSC CCD (cooled), but I also shoot MINIMUM 10 minute long subs. I took this with an 85mm scope, OSC CCD, 10 min subs, next to Canberra Airport (8hrs total subs so far - going for 16 hours :eyepop:): https://www.astrobin.com/full/343506/F/ - and half of that 8hrs was done in 68% Moon... and Corona Australis is VERY close to the Moon at that.

You got nice colour balance and good focus too this time Alex. Well done.

[xelasnave]

Thank you JA and thank you Lewis.

Lewis I am driven to short subs mainly because of poor polar alignment but the experience using short subs has been interesting particularly in the city where sky glow limits the exposure or the iso.

I still have not got my auto guide working which simply needs a bit of time outside but when I get the rarity of a clear sky I opt to get something unguided and forget about any attention to making the auto guide work...plus before I get into that the mounts both of them need a pull down as each can be improved upon.
My main problem is I just aint as good as I used to be and everything is such an effort...
Anyways I am happy that at least under current procedures that noise is not that big a problem...I hope the dithering helped but I need a with and without test I guess.
Thanks again for all the help from all.
Alex