Help me evaluate tilt and/or spacing (CCD-inspector)

[MartinF]

I have problems when using my Skywatcher 150-PDS newtonian and my ASI1600MM-Cool. I know I have some tilt but I think there is also an issue with the spacing. Could someone help me evaluate these CCD-inspector results?

Do I need to add spacing or should it be less? The images where taken using the Zwo Lum-filter. When using an Astrodon 3nm Ha filter (thicker), how should the spacing be altered then?

[MartinF]

And here is the result with my Sigma 500mm tele lens. Looks OK or similar issues?
Will post results from the Astrodon Ha-filter later.

[yobbo89]

are using a coma corrector if so what are you using ?.

i don't think the filter is the problem unless it's sitting at a large angle.

what is your collimation like ? are you using a laser and a cheshire ?
is your focuser square to the tube ? i have a brief instructional post to do so if you're interested.
what does your star test look like ?

my opinion it looks like slight collimation and slight tilt together is off.

the sigma looks fine.

edit: good idea ,i haven't checked my collimation in awhile, i'm going to buy a key for my ccd inspector as it has expired.

[yobbo89]

so the CCDIS/P Plug-in that comes with ccd inspector 2 can help collimate your scope/tilt, i'll have to give it a go

[MartinF]

are using a coma corrector if so what are you using ?.

i don't think the filter is the problem unless it's sitting at a large angle.

what is your collimation like ? are you using a laser and a cheshire ?
is your focuser square to the tube ? i have a brief instructional post to do so if you're interested.
what does your star test look like ?

my opinion it looks like slight collimation and slight tilt together is off.

the sigma looks fine.

edit: good idea ,i haven't checked my collimation in awhile, i'm going to buy a key for my ccd inspector as it has expired.

I use the Baader MPCC mkIII coma corrector. For collimation I use a simple laser collimator, like this one:

For comparison, here is an image taken with the same scope but with the thicker Astrodon 3nm Ha-filter.

[yobbo89]

these are months apart, ha-oiii-sii and red channel ,

The red channel differs a bit to the others.

i've noticed that poor data ruins results in ccd inspector like slight tracking error ,a small defocused problem , pretty sure ccd inspector totally relies only on star profile data,even being over exposed gives issues in ccd inspector.

i'll have to do further test in one whole night of narrowband and wide ban rgb.

[yobbo89]

see only my red channel shows a problem, 7 fwhm , which doesn't look correct, it should be about 3

[MartinF]

is your focuser square to the tube ? i have a brief instructional post to do so if you're interested.
what does your star test look like ?

I´m not sure what you mean by star test but I wouldn´t mind that instruction you mentioned!

[yobbo89]

A star collimation


Have a read on some of my post in this thread about collimation a focuser square to the scope ota

http://www.astronomyforum.net/dobsonian ... cuser.html