Secondary mirror rotation is slightly off, ok?

[pat]

I read that the secondary rotation can be somewhat off. And this will not effect viewing. If this is so I will leave mine alone? Pat

Too many stars too little time**********

[Freff]

uh!!!!

[umadog]

Secondary mirror rotation issues may cause you to lose light. It's easy enough to get it right, so you might as well do it. Here's how:

Telescope Reviews: Useful info about secondary mirror alignment

[yeti monster]

Where did you read this?

[pat]

I'm subcribed to three forms ,sorry that I can't remmber where. Pat

[umadog]

I think I know what Pat is recalling. In the link I posted above, Jason mentions that secondary mirror alignment is relatively less critical for visual observers. If it's off, then the 100% illuminated area won't be in the centre of the FOV. Scroll down to post #3035954.

[yeti monster]

Ah! I read 'rotation' to mean the secondary carrier rotated on the OTA axis. When collimating I use my laser collimator to ensure that the secondary is as bang on as I can get it, before moving onto any primary adjustment, which seems to work for me as star tests are usually good or very close after collimation. This is critical on my SNT as it is f/4. Thankfully the secondary carrier on the SNT has an orientaion peg which prevents it from rotating on the OTA axis.