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Old 14-04-2021, 03:53 PM
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Karlz (Karl)
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Halfa Chook w/o the fries

While doing the Pterodactyl I could only get so far before the dreaded palm tree blocks my view, Having already had Running Chicken at my usual focal length of 1056mm, I decided to add more time to what I already had.

I got this over 3 nights in the week just gone, I was trying for 600 sec last night but the mount had a bug after acquiring more sub time and dialing my OAG on another DSO.

If you are using filters I had found it is good to have it as close to the camera in front of the reducer, I have many subs cropped due to some funky stars till I changed my config.

Only use 300 sec subs on this as the 600 weren't playing the guided game, APP doesn't give me an approximate time to the total stacked but I'm going to say it's about 6-7 hours.

I was going to rotate the image after doing all the odds and sods I ended up leaving as is, I was a larger image than what I've posted yet when you use different rotations of the focuser your image tends to shrink

Equipment used is in my sig

Thanks for looking.

Karl
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Old 14-04-2021, 08:16 PM
Startrek (Martin)
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Karl,
Superb chook
Nicely processed and Bok globules well defined against the nebulosity
Colour blends really nice too ....
By the way 300 sec subs on a cooled OSC is more than enough exposure on unity gain or highest dynamic range
I normally stick with 3 minute on my 2600MC at Highest Dynamic Range (Gain 0)and has performed well with a broad range of objects ( my image scale is 0.77 arc sec per pixel )
600sec subs challenges your guiding and tracking unnecessarily unless your imaging faint fuzzies
Cheers
Martin
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Old 14-04-2021, 09:13 PM
Zuts
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Very good definition and a lovely colour image. I would like to go for 5 or six hours but there are so many objects to try and catch .....

I sometimes go for 10 minutes, depending on the object but usually stick to 5 minute subs.

Last night I found out that even that on some objects is far to much, 5 minutes on the Sombrero galaxy blew out everything, a waste of 2 hours of data under dark skies at Wiruna. Next time I will try half that.
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Old 14-04-2021, 09:17 PM
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Karlz (Karl)
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Thanks Martin,

I don't use unity gain or high dynamic range as I've found them not to produce enough signal. I did have a interesting read which wasn't taken to, it describes how best to use gain and offset to get the best from your camera. I've tried 180, 210, 300, 420 and 600 sec and there is a big difference between 180 to 300 to 600 in signal coming through, like you said to me push the camera which I do and I push the filter too.
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Old 14-04-2021, 09:18 PM
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Thanks Zuts, OAG is the go for good guiding numbers and good stars.
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Old 14-04-2021, 09:53 PM
Startrek (Martin)
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Quote:
Originally Posted by Karlz View Post
Thanks Martin,

I don't use unity gain or high dynamic range as I've found them not to produce enough signal. I did have a interesting read which wasn't taken to, it describes how best to use gain and offset to get the best from your camera. I've tried 180, 210, 300, 420 and 600 sec and there is a big difference between 180 to 300 to 600 in signal coming through, like you said to me push the camera which I do and I push the filter too.
Karl,
When you mention more signal with longer subs do you mean more brightness in the sub and higher peak on the histogram more to the right ?? , if so then just remember that addition signal has also additional read noise, shot noise and dark current too which you have try to reduce through dithering, darks , stacking and processing etc...
There is a trade off between signal and noise floor and each camera performs differently
In my case I’ve found pushing beyond 300sec subs on my 2600MC reduces fine detail in my objects compared to 180 sec and 240 sec
I tried it with M83 a week ago and the image with 180 sec subs , although not as bright, definitely had more fine detail in the core and spiral arms ( both 300sec and 180sec were stacked and processed the same way , same integration time )
As I mentioned every camera and image train is different, plus conditions can change from night to night week to week
Keep posting your excellent images !!
Cheers
Martin
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Old 14-04-2021, 10:40 PM
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Karlz (Karl)
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Signal being data and not clipping blacks, I've always dithered and use the required darks, flats and so on. Your high guide numbers would reduce your detail as well, I did some 600 sec subs on pterodactyl which great star shape across the field, i just wish I figured the filter/ reducer before I started it
I saw your M83 and reminded me when I use to live in bortle 2, I just wish I had the camera and filters I have now.
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Old 15-04-2021, 09:36 AM
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Sunfish (Ray)
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Great chicken dinner. Great framing and colour. Chicken is a good fall back I also found when the lower creatures go into the trees. Mine was a little too legless though.
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