double images on mars

[Daniel-K]

i cant seem to get it into focus not matter what i do.i was using a 12mm EP. the collimation is spot on i have a shroud on and a dew shield bought the scope 2nd hand but have just had a check over and the mirror has lost some of its coatings! most of it is on the left of the mirror. i only just noticed this after leaving the lid of with the scope laying flat come down this morning to put it all back standing up and with the sun streaming in behind the mirror through the window i could see the flaws! do you think i should get it re coated?

[Moonshane]

I doubt that the damage to the coatings will impact on the visual image at all. it looks like a bit of mirror clip 'rash'. you could 'remove' some of it by turning the mirror a little so some is under a clip. at the same time you could check if the clips are loose enough - they should not be touching the mirror.

however, it's unlikely any of this will be creating the double image mentioned. this is more likely to be either inadequate cooling or seeing so don't worry.

[Asimov]

Won't affect your views one little bit. Just use it Daniel:) As mentioned, nothing to do with double images, seeing &/or tube currents the culprit(s).

[Daniel-K]

sweet! thanks guys i am a bit of a panicer!

[Moonshane]

no worries, it's a lesson in observing that the only place you should look on a telescope is through the focuser, this will usually tell you all you need to know