OO F4.8 collimation

[Theninjagecko]

I think my laser colli is out of collimation but I used it after really getting my scope out of colli before using a Cheshire and coli cap. It looks good in the coli cap and Cheshire with 3 clips even and visible but it kind of looks like the primary doesn't fill up the secondary, and as if I can see some of the tube.

The Cheshire cross hairs are dead centred.

I might buy a Hotech laser collimator. I have a question though, Presuming the Hotech laser was collimated itself perfectly would my scope pretty much be collimated once aligned with the Hotech? Would it still centre even if the secondary was to close or too far up the tube away from the mirror "not central with the focuser"

[cs1cjc]

You can tell if your laser is out by rotating it. If the spot stays fixed then it is OK. However a laser collimator is also dependent on the focuser being perpendicular. If the cap and Cheshire say it is OK then it may be worthwhile doing a star test to check.

I am unconvinced in principle about laser collimation (without a Barlow), but in practice I find that the Baader unit I have works well.

Good luck!

[NGC 1502]

it kind of looks like the primary doesn't fill up the secondary, and as if I can see some of the tube.

Same with my OO 10" F4.8. If I rack the focuser right in, fit a collicap and look, I can see some of the tube surrounding the primary mirror.

Either we don't have a problem, or both of us do

Regards, Ed.

[Theninjagecko]

I've brought a Hotech laser collimator now. Save me wondering if its collimated all the time or not lol.

[sgazer]

I found a cheshire collimator worked well, but a star test was best, using the 'slightly out of focus' technique.

[enar1948]

If the cap and Cheshire say it is OK then it may be worthwhile doing a star test to check.