Silly collimating question….

[Neutrinosoup]

I’ve never collimated a telescope before (refractors up until now).

I bought a SvBony laser eyepiece collimator:

It looked like my secondary mirror was slightly off centre (red dot outside the target) and the primary out to slightly larger degree. So I corrected the secondary, then when I moved to look at the primary it was now also in perfect alignment?

Is it usually as easy as this! Just a small tweak to the secondary?

(8 inch starsense explorer dobsonian)

[wookie1965]

As long as the secondary is in the right place (small mirror) you will only need to tweak your primary (big mirror), if you don't drop or bang the tube you should not need to touch the secondary again. 

[PeterC65]

Yes, collimation of a Newtonian using a laser collimator is straightforward, providing you only need to adjust the primary mirror and / or make small adjustments to the secondary mirror, as you have done. It gets much harder if you try to make bigger adjustments of the secondary mirror, to centre it under the focuser for example, and to do that you need something like a Cheshire Collimating Eyepiece. Doing what you've done is usually sufficient though, and usually only the primary will need minor adjustment prior to a session (I always check it).

 

[Mr Spock]

It really is simple  

 

[Ricochet]

1 hour ago, Neutrinosoup said:

Is it usually as easy as this!

No, you would usually have to adjust both mirrors. However, what you have described makes sense. When you collimate with a laser any error made in the collimation of the secondary will result in double the error in the primary collimation. It sounds like your scope was collimated in the factory and during transport only the secondary moved, hence you saw that the secondary was out and the primary was further out. When you fixed the error in the secondary it also fixed the larger error in the primary because in reality that error didn't exist, it just appeared to due to the error in the secondary.

[happy-kat]

It's in the guide linked above, but first before twiddling any adjustments on your telescope I'd check your laser collimator is true

[Spile]

Note that a laser will not confirm or otherwise that your secondary mirror has offset error. It’s much easier to check for secondary errors with a Cheshire eyepiece and sight tube combination tool and in addition you won’t get distracted by registration or collimation errors.
 

Edited January 7 by Spile