Secondary problem!

[sbooder]

I wonder if anyone could help. I am finding the collimation of my SW 250P secondary the most frustrating I have ever had to do.

For the life of me I can not get the primary clips to show in the image. I have tried normal site tubes, a Cheshire, and a 35mm film canister. It is like the secondary is just not big enough to see the entire primary.

Anyone else with this scope had the same problem or if not what are you using to align the secondary please?

[Peter Drew]

Hello Simon.

It could well be that your secondary is on the small side in which case it might not be possible to see the full mirror from your collimation position. The eyepiece or a camera focuses further in than your eye so it might not be too small. A way round this might be to make a sub aperture mask to fit over the primary mirror, this would enable you to see an accurate outline of the mirror, you could even add false clips.

[kniclander]

on my 250 px I can only see the clips if the focuser is racked nearly all the way in.

[sbooder]

Thanks chaps. I have found a solution for that part of the collimation. I just made a pinhole cap with no depth to it. I can now see all the clips.