Focuser tension knob on SW evostar 90

[Russko13]

So just above where the focuser is on the OTA there is a metal tension knob such as the ones found all over the scope e.g to secure diagonal in scope or secure eyepiece in place, is there any particular tension it needs to be set to or do I loosen it, focus and re tighten, such a noob question but being my first scope I did wonder :s

[daz]

Unless you are swapping heavy camera's and EPs, there is usually no need to keep adjusting the tension. Get it set to a good tension so that the draw tube doesn't slip and you're good to go!

[ronl]

If I am observing a target for a long time and have good focus,

I tighten the screw a little just in case I move the focus knob by 

mistake, and just loosen it a little when I change the eyepiece,

it's best to have just enough tension on the screw to turn the focus

slowly, that way when you have achieved focus it just takes a slight

turn to lock it.

[Russko13]

Thank you