Astigmatism or collimation issues?

Hello all,

I am an amateur at best, and I have a much older 4.5" f8 reflector. It does fine with Jupiter, Saturn, and star clusters seem sharp when I can get on them (the finder scope is a joke).

My problem is, whenever I try to observe Mars or Venus, I just get this awful "double image" thing a lot of the time. I have only had the collimation done once 2 years ago (by someone else who knew how) and I don't even have the tools for doing it or know how. I also wear glasses for being near-sighted (I have astigmatism) and I wonder if that could be the issue?

Here's what I saw last night, in above average seeing, transparency, etc. Mars was a nice orange disk... but seemingly too glaringly bright. Then the image would "wobble" and I would kind of see an overlapping, brighter image over the crisp one. Then for a fleeting moment I would see just the crisp disk again, and even thought I may have detected some contrast on it, then it would "sparkle" again and wobble around, and I just couldn't focus on it (the focuser was fine, I mean I couldn't stabilize the image in my eye).

What do you folks think is going on? I was trying to observe using a 41mm plossl and 2X barlow. Using a few color filters helped some but not enough.

Ken

Hi Ken,
Atmospheric condition cause this a lot. Last Thursday night a friend reported that at Mt Pinos he had 4 images of Mars converging into 2 images at times due to atmospheric disturbance. 8O I have seen this myself before at Mt Pinos a couple of years ago. The skies seemed clear but this is what it looked like.
I would assume this is exactly what you are experiencing.