I am not sure if this topic has been discussed somewhere in here, if yes, please direct me.
I have been wondering if the RASA spacing needs to be adjusted depending on the filters we are using. Celestron indicates that if we use filters the clear window needs to be removed. So this clear glass window is 2mm thick, so it means that if we use a filter for examples, an Astronomik filter which is 1mm thick, we need to increase the spacing 0.5mm or if we use a 3mm thick filter we need to reduce the back focus spacing by 0.5mm. Would this be correct? I think the RASA is very touchy and spacing is critical for perfect star field.
So far, I have the telescope which I send for a repair due to mirror tilt and I got it back, but the weather looks bad for the next week, so I am wondering if anyone have look into that.