Focussing

[Cjg]

Having spent many hours observing, and running through the specs on / specs off routine, trying to get a decide which gives the best view: why does astro gear not work in the same way as photography gear in that with a lens on a camera, a distant church or say the moon would be focussed at "infinity", whereas a telescope does not?

Would the views be poorer, is it a depth of field issue?

I am struggling to get my head around that Jupiter needs a different focus setting to say Capella when with a camera lens they would both need to be focussed at infinity!

Sorry if this is garbled, late night and early start etc.

Cheers

Chris

[Merlin66]

There's no difference in the focus position between Capella and Jupiter (or the moon)

The problem is the atmospherics and small changes in the telescope - which breathes with temperature.

Our eye is a very sensitive receptor and when to try to focus we can "chase" the seeing...

The depth of focus, depending on your telescope, is usually around 50 - 100 micron.

[Cjg]

Thank you!