Quote:
Originally Posted by JohnG
I have been getting a similar arcs when pointing in some directions, with help from another member here I had thought I had tracked it down to the edges on the shutter aperture of my dome, I thought it may have been light from a rather bright street light reflecting off the edges, I blackened them but a test still showed the arcs. 
I then shone an averted light down the tube from the front and saw a major reflection coming off the front of the draw tube. The focuser is a Moonlite and the end of the draw tube is an anodised gloss black. I have taken the Moonlite off and now have the original Takahashi focuser fitted, it has a matt black end piece on the draw tube and I can't remember ever seeing these arcs from it.
Whilst I only did this yesterday, I haven't had a chance to test as yet due to clouds last night but I believe this to be the culprit and hopefully will be testing again tonight.
Sounds to me like you are having the same problem with an off-set star reflecting light off the end of the draw tube, I would think about taking the focuser off and blackening the end of the draw tube.
Cheers
John G |
Glad to hear you've got it sorted out mate.
