SW 200p collimation

[YogSothoth]

Hi All. I’ve had my 200p f5.91 for a couple of months and was just wondering about the collimation. I’ve taken a photo through a collimator cap and was wondering how much people thought the collimation was out by if at all. Many thanks.

[Pixies]

Hi,

It's hard to determine the alignment of the secondary mirror using a collimation cap, but you can see the 3 primary mirror clips OK and things look reasonably circular, so probably good enough for visual.

However, the primary could do with a little adjustment. You need to adjust the primary mirror so that the collimation cap eyehole is inside the 'doughnut' marker on the primary. Currently, yours is like:

 

[YogSothoth]

OK cool. Thanks for that. I’ll have a look at the primary.

[Spile]

The potential for parallax errors make it difficult to make a call when judging alignment from a photo. A Cheshire eyepiece and sight tube combination tool make it easier to assess the secondary. 
https://astro.catshill.com/collimation-guide/

[bosun21]

Placing a sheet of white paper behind the focuser can show you the position of the secondary relevant to the focuser tube. 

[YogSothoth]

Thanks for the replies. I’ll have a look at the primary. It’ll give me something to do while it rains non stop 😂

[dweller25]

As above plus the secondary appears to be slightly tilted too in the East, West direction, BUT that could be camera placement.

Edited December 27, 2021 by dweller25

[bottletopburly]

Also check the focuser is 90 degrees to the ota which I only found out was off on my 200pds  , wind the focuser out fully put on any extensions then run a long ruler along the spider vane so you can see if focuser is parallel with ruler , mine was so far off I could see it was off without me he need for a ruler , only takes a minute, only doing this finally I could get the secondary centred and looking circular as it should be .