I was undecided about setting up or not yesterday afternoon until the clouds dispersed after dinner and left a nice clear blue sky around 7pm ( CFN is not very reliable after the Local forecast model was taken away last year and it showed cloud from late afternoon ) Will I or won’t I , bugger it , so I set up which normally takes me a leisurely 2 hours but yesterday evening took me an hour and a half
I was polar aligned by 9.20pm and framed up and focused on M42 just past the Meridian
Captured only 5 x 180sec subs as the cloud did roll in from the west / south west ( sub 4 and sub 5 were cloud affected by high wispy cloud )
Scope: 6” f6 Bintel newt
Mount: EQ6-R pro
Imaging Camera : ZWOASI2600MC Ascom control set at Lowest Read Noise ( Gain 100 ) cooled to -12C
No filter used - under Bortle 8 skies ( no moon around )
Goto and Navigation EQMOD And Ascom Stellarium
APT Frame focus and capture
PHD2 guiding at 1.2 arc sec error ( dithered subs )
Only 5 x 180sec dithered guided subs ( 15mins integration)
No darks
No flats
Stacked in DSS ( Average )
Processed in Startools V1.6
Original Frame version
Crop version showing nebulosity detail
Core a bit blown out ( should have used my ZWO Duoband filter and set the camera to Highest Dynamic Range ( Gain 0 ) which resolves the core and exposes the trap stars really well without the need of Layering techniques
One of the shortest and rushed imaging sessions I’ve ever done
You just wanted another reason to show off those stunning diffraction spikes again didn’t you ? Hahaha.
Well done
Thanks Ryan
Don’t worry about the diffraction spikes, but yeh they do look good , I’m just stoked to see the detail in the image from just 15mins of pretty ordinary data with my trusty old 6” newt ( cost me $299 just over 3 years ago ) who needs an expensive telescope !!
The camera does help too
When the weather improves I’d like to see some more images with your f4 !!
I've had good success with Cloudy Nights, here in Sydney and at my usual go-to dark site.
Nice image. Amazing how sensitive this camera is. Any reason you chose gain 100? From what I've read, generally it's Gain 0 for broadband, and Gain 100 for filters?
I've had good success with Cloudy Nights, here in Sydney and at my usual go-to dark site.
Nice image. Amazing how sensitive this camera is. Any reason you chose gain 100? From what I've read, generally it's Gain 0 for broadband, and Gain 100 for filters?
Thanks Adam
Yeh I was really pleased with the image with just a few subs
I’ve used Cloud Free Night ( CFN ) for over 3 years now and it use to have to local forecast model Access C from meteorological weather stations which were very accurate forecasts. Now with only GFS models ( US ) it’s no where near as accurate , in fact to test it out , in the Meteorgram I punched in Sydney looked at the graph , then punched in Liverpool , looked at the graph , and they were entirely different. Did this every 4 hours through the day and night over a couple of days and yep entirely different forecasts. Sydney’s only 32km from Liverpool , not 150km
I still use it but don’t rely on it like I use to
As far as Gain is concerned on the 2600MC, l like to dabble a bit as I’m still learning about this new camera ( I’ll need a year to nut it out properly) at Lowest Read Noise gain 100 , you lower your read noise a bit but still get good dynamic range , so actually gain 0 and gain 100 are very similar , however on gain 100 you only get to 18,000 e- FW whereas with gain 0 you reach almost full well at 50,000 e-
So Gain 0 is suitable for both light polluted and dark skies as well as Narrowband
Still experimenting
Martin
Panning around the edge of the image, I wonder if you have some coma going in? The close up crop shows eggy stars, so I had a look at the main image. Centre looks solid, but each corner is stretched toward the centre? It's most noticeable in the bottom right.
JP
Thanks
I think the eggy stars are to do with tracking and guiding rather than coma and it is accentuated on the really small faint stars due to image scale and resolution
I’ve tested this scope without my Baader MCCP MkIII coma corrector and coma is so evident as it affects all stars in the off axis areas especially pushing 3 minute subs
Guiding that night was really poor ( for the half hour I was running the mount ) RA and Dec never crossed paths , they both stayed above and below 0
Good pick up though , I was hoping nobody would notice , they normally just focus on the big bright stars with those huge diffraction spikes
Martin
JP
Thanks
I think the eggy stars are to do with tracking and guiding rather than coma and it is accentuated on the really small faint stars due to image scale and resolution
I’ve tested this scope without my Baader MCCP MkIII coma corrector and coma is so evident as it affects all stars in the off axis areas especially pushing 3 minute subs
Guiding that night was really poor ( for the half hour I was running the mount ) RA and Dec never crossed paths , they both stayed above and below 0
Good pick up though , I was hoping nobody would notice , they normally just focus on the big bright stars with those huge diffraction spikes
Martin
Gotcha! And I was just raising it incase it was something you'd like to address, not trying to be a downer Please always air any feedback on issues with my images! I'm really just posting for feedback from people with your eye and experience, with an eye to improve 👍👍
Gotcha! And I was just raising it incase it was something you'd like to address, not trying to be a downer Please always air any feedback on issues with my images! I'm really just posting for feedback from people with your eye and experience, with an eye to improve 👍👍
Thanks JP
I’m probably my own worse critic , always to hard on myself when I finish processing an image. I show it friends and family and they say “wow looks fantastic” then I start picking all the faults out of it. Not the way I should respond. I should say yeh thanks, next time I’ll try to improve it
Thanks again , I look forward to any comments whether they are praise or criticism
You never stop learning and trying to improve in this incredible hobby
Clear Skies
ive had a few of these, hey weather apps says cloudy but I see stars, "will I won't I" moments in the last few weeks... glad to see you went with it...amazing what 15min can get these days with cameras like the 2600!
ive had a few of these, hey weather apps says cloudy but I see stars, "will I won't I" moments in the last few weeks... glad to see you went with it...amazing what 15min can get these days with cameras like the 2600!
Panning around the edge of the image, I wonder if you have some coma going in? The close up crop shows eggy stars, so I had a look at the main image. Centre looks solid, but each corner is stretched toward the centre? It's most noticeable in the bottom right.
JP
I think I’ve found the problem with eggy stars
It’s “tilt” in my camera
I just realised I’m using a new coma corrector and the old one had a piece of electrical tape on one side opposite the grub screws which I’ve used with the new camera and perfect stars
I was out last night imaging with new coma corrector with no tape and same issue on Carina
I’ll fit the tape on the new coma corrector and wait for the next clear night to test
Should sort the issue
Cheers
Martin
Please always air any feedback on issues with my images! I'm really just posting for feedback from people with your eye and experience, with an eye to improve 👍👍
