CCD Inspector

[Fay]

I have just found that it opens a can of worms when looking at my images with CCD Inspector Should unprocessed subs be used or processed? How much curvature is acceptable? Why do I have a collimation issue using ED80 or 120?  Thanks

[RobertM]

Unprocessed.

Do you have a collimation issue, is it focuser sag or something else... there are lots of things CCD Inspector can tell you but the tricky thing is interpreting the results.  Also expected curvature is different on different types of scopes but, 'generally', anything less than 10% is good, but then again that depends on the size of your CCD and the area over which you're measuring.  If you're using a DMK 1/3" CCD and you get 10% then that may be considered 'terrible' but 10% across a full frame CCD exceptionally good.

Do you have a collimation issue with the ED80 or 120 - how do you know that ?

Robert

[Fay]

Robert, you have outlined a lot of areas that have to be taken into consideration.

I was only having a look with processed images & on a few, the large circle with the cross, collimation screen, the cross's were not lined up, but , Robert, I have not been very picky  with the info probably. I would have thought that using the dedicated flattener with ED80, the plane would have not shown any curvature using the Atik.

I think the collimation screen could be very handy when collimating a scope.

[Fay]

Had a look at a few single subs, & not so bad, my interpretation. Collimation changes a bit, but wondering if to do with camera not being seated squarely from image to image

[RobertM]

Firstly you should apollogise to Mark for the thread hijack ....   the Police will be on you in no time now... 

Secondly, I've just done a couple of measurements and by comparison...

Canon 200L lens with ML8300 has curvature of 17% with the Collimation 4.2 pixels out
The Sky90 was 23% and the collimation was 3.6pixels out (this is due to focuser being too loose.
Skywatcher 190MN with EOS450d was 13.8% and the collimation is 3.6 pixels out

Robert

[Mike]

She's old. She probably doesn't even know what day of the week it is.

[Fay]

Get a life Mike!!!!!!!!!!!!!!!! At least I am not like Victor Meldrew as you are

[Mike]

I don't belieeeeeeve it !

[Mike]

I'd rather be Victor Meldrew than Mrs. Slocombe

[Rocket Pooch]

Fight Fight !!!!!!!!!!!!!!!!!!!!!!