My collimation is completely screwed up! Help!

[james335k]

Hi everyone,

I learned a valuable lesson a couple of days ago. Never leaving your scope out in the open with small children around. I'm sure it's common sense really but I'd been imaging the night before and the scope (Celestron 8" SCT) was lying idle on the sideboard. To my horror I discovered my 5 year old nephew playing with the Bob's Knobs on the scope! Luckily there's no permanent damage but the collimation is completely screwed. Stars when viewed throgh the scope have an elongated cone like appearance. Does anyone have any suggestions for getting a rough collimation back? From there I'm sure I'll be able to correct the allignment.

[barkis]

Oh dear, kids heh?

Collimating a SCT is not difficult James, especially with Bobs Knobs fitted.

This link will help I think, If not, just come back and we'll talk you through it.

Ron.

Daylight Collimation of SCT or Mak

[Psychobilly]

Oh dear, kids heh?

Collimating a SCT is not difficult James, especially with Bobs Knobs fitted.

This link will help I think, If not, just come back and we'll talk you through it.

Ron.

Daylight Collimation of SCT or Mak

And me to although I cant blame Kids for my collimation woes... it's all Billys fault...

I did spend some time with metaguide and a webcam last night and have got it a lot better than it was....

Peter....

[james335k]

Thanks for the reply Ron. This is exactly what I'm looking for.

[james335k]

Hi Peter, Thanks for the idea of using a webcam. I'm sure it's much easier to fine tune on a screen than through the eyepiece.

[Psychobilly]

Here's a link to the software...

If you have the pc connected to control the mount the software also guides to keep the image centered as you make the collimation adjustments... as well as "avergaing" the carp seeing and displaying ISO lines so you can see which way to adjust...

Peter...

[ollypenrice]

Just out of interest, another approach; this is the indoor method which can have advantages (when the kids have gone to bed..) To be fully indoor you'd need a room about 30 feet long, minimum. Warehouse, big garage etc. Or you can work between one covered area (your lounge?) and another in view of it. (Your garden shed?)

You make an artificial star by glueing a small ballbearing onto a black card. This you illuminate from not too far away with a focussed beam such as from a bike lamp.

This is your test star so you can keep it dead central and it won't move or be in a silly place like up in the sky. Light reflected from the bit of the ball nearest your lens will give a good approximation of a point source. I found I got a great result by this method. It is well known but I heard it from a TeleVue optician whom I contacted regarding a damaged Genesis I had bought. The venerable instrument was soon in the best of health and still is. If it is cloudy and you are in an agony of mind to see your scope in order again this might be for you. The webcam methods (about which I know nothing) could also work with this handy all-weather star, maybe?

Olly.

[Psychobilly]

Yes the webcam methods work well with atrificial stars as well...

I made a fibre star out of the fibre optic toch kit that you can buy for a few quid in maplins although I have replaced the palstic fibre with a 16 um glass one... just I ahvent got a decent line of sight palced to mount it now the scopes on the pier...

Peter....

[james335k]

Thanks guys, you really have been most helpful.