first time collimating help

[Ursa Major]

I have owned a 130p heratige dobsonian for the past two months and feel that the time may have come to perform the dreaded first collimation:eek:.

I have taken a picture down the focuser and am hoping someone may be able to tell me what i need to do. I have noticed that the secondary mirror support is not lined up with the center of the primary mirror, is this important?

Thank you, Laurie.

[Peter Drew]

This looks nearly collimated to me, a slight tweak on the primary mirror adjustment should centralise the image of the secondary holder. It is important to get this as near as possible for the best optical performance.

[Bizibilder]

Have a look at Astro Baby's tutorial on collimation:

Astro Babys Guide to Collimation

It takes you through all the steps in an easy to follow style.

Collimation is a bit like riding a bike! Once you know how its easy!

[tms48]

I also have this telescope and the support arm is not lined up exactly with the cross wires even when everything shows as well collimated through a cheshire eyepiece. The support arm is parallel but off to one side, this doent appear to have an effect on the viewing images and may be just a feature of the telescope.