Problem of size in calibration images made via CCD Autopilot V5  

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(@jb-gayet)
White Dwarf Customer
Joined: 1 year ago
Posts: 12
February 12, 2018 11:26  

Hello all 🙂 

Well, rather than bothering Mabula with emails, maybe I can share here this problem I face as a beginner....

I am trying to process my first Lights (acquired a month ago, thanks to this great weather...). I work with CCD AP 5, MaximDL, Focusmax and TheSkyX Pro in remote. The camera is an ATIK 4000 M. 

I used the routines of CCD AP to make darks, bias and sky flats. It turns out that the Lights and FLATS are 2042 x 2042 pixels wide, but the BIAS and DARKS are only 752 x 580 , hence the following message from APP when trying to Calibrate :

"Bias Calibration is not possible due to different frame dimensions" (cf. pic linked).

I could not find a setting in the CCD AP option tabs for the size of the calibration images, so I guess this should not matter. Do I miss a step in the calibration process ? Or is it truly a problem at images acquisition ?

TYVM in advance 🙂

JBG

 

PS : sorry for my poor syntax 😉


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(@jb-gayet)
White Dwarf Customer
Joined: 1 year ago
Posts: 12
February 12, 2018 11:29  

BTW , I posted a similar question on the CCD Autopilot forum :  http://ccdware.infopop.cc/eve/forums?a=tpc&s=290100098&f=9997083106&m=1117092986&r=1117092986#1117092986


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(@mabula-admin)
Quasar Admin
Joined: 2 years ago
Posts: 1844
February 17, 2018 22:25  

@jb-gayet,

I can't see your topic on the CCD Autopilot forum, because I don't have a login unfortunately. Did you get an answer there?

I can only assume this might has to do with binning somehow of the sensor of your CCD camera, or some settings in the capture software.

To be able to do proper calibration, the calibration frames need to be the same size as the lights, because calibration is something that works on pixel scale to do it properly.

If there was binning, like 2x2 I would expect the frames to show the 2x factor. So for the 2048x2048 frames, the calirbation frames would be 1024x1024 for instance.

The fact that the frames are 752 x 580 really puzzles me, because the aspect ratio of the frame is different as well.

I would be curious to know the asnwers on the CCD autopilot forum.

Kind regards,

Mabula

Main developer of Astro Pixel Processor and owner of Aries Productions


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(@jb-gayet)
White Dwarf Customer
Joined: 1 year ago
Posts: 12
February 18, 2018 20:09  

Hello 🙂 Well the solution came by the previous owner of the camera who used CCD AP5 too and told me that the sole solution he could think of was that the dark had been obtained via the guider camera (ie Lodestar X2) and he was right 🙂 the image size was the exact size of the Lodestar 🙂 

 
The question for me was then to understand how such thing  happened and I finally found out that in MaximDL, the "guiding camera" box option was checked to "1" (and not to "2") which means that, for maximDL, the guiding camera was the ATIK 4000 and -I guess - the main camera was by default the Lodestar. Obviously this information was sent to CCD AP 🙂
 
 
So, you were right to be puzzled by this weird ratio 😉
 
JB

 


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(@mabula-admin)
Quasar Admin
Joined: 2 years ago
Posts: 1844
February 20, 2018 22:04  

@jb-gayet,

Thank you JB, that explains a lot  😉 

Mabula

Main developer of Astro Pixel Processor and owner of Aries Productions


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(@gregwrca)
Neutron Star Customer
Joined: 2 years ago
Posts: 222
February 21, 2018 03:08  

Still laughing. Sounds like so many mistakes I've made..... oops forgot to check there.

GW


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