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Is this in focus?

Posted: Fri Sep 24, 2021 10:56 am
by brenski
Would someone be kind enough to have a look and tell me if this allsky image is focused correctly?
is it sharp enough?

Zwo 178mc

Image

Re: Is this in focus?

Posted: Fri Sep 24, 2021 6:34 pm
by admin
Hi,

all sky cameras can be tricky to focus - if you are using a glass/plastic dome then the curvature means that it introduces some errors to the focus, so the image can look sharply in focus with the dome off and then be a bit blurry with the dome on. It may not be a case of 'is this in focus'?, but more 'is this the best focus I can achieve'?

cheers,

Robin

Re: Is this in focus?

Posted: Fri Sep 24, 2021 9:19 pm
by brenski
thanks @robin

I have been trying to adjust focus with the dome off, however, as soon as it looks correct and I re-tighten the lens screw, the next capture looks "out". and that's BEFORE i reapply the dome!

i heard there was a trick to adjust focus more precisely, by first adjusting the actual lens collar from the camera, taping it down and then applying fine adjustment to the lens itself.

is there a quick and easy guide to how to do this?

thanks

Re: Is this in focus?

Posted: Sat Sep 25, 2021 6:38 pm
by admin
Hi,

I don't have any tricks to share - I did mine by length trial and error :( Maybe other all sky users have some suggestions.

cheers,

Robin