star trail focusing question

[ecp1977]

I was wondering what the best way to focus my lens is for photographing star trails. I seem to find more information on aperture, ISO and exposure times than I d for focusing when I search online. I have tried focusing on particular stars but my lens keeps searching but doesnt; lock focus. I will be using a lens that can be set to infinity so should I just switch to manual focus, set to infinity and take the picture? Thanks.

[Pilp]

hi, im not an expert photogropher by any means, but i am an astronomer in my spare time, star trails should be easy, set to bulb, focus to infintiy then just leave it to it, if your northern hemisphere then aim for polaris and try and centre that star then everything will trail around that point

[ravncat]

Originally Posted by ecp1977

I will be using a lens that can be set to infinity so should I just switch to manual focus, set to infinity and take the picture? Thanks.

That's the easiest way to do it

[Aegea]

Use live view and manual focus to focus on a bright star, then don't touch the focus ring.