8 x 50 Finderscope not working properly

[prabal276]

Hello,

I recently got my new 8" Dob Telescope. I tried to see Jupiter yesterday. However, while aligning the Finderscope, I noticed that Jupiter wasn't a pinpoint image it appeared like a bright star and had 4 spikes coming off it. Looked much more like betelgeuse. I also tried to look at a star through it. It was better but I had to work my eye to make it a pinpoint.  I tried rotating the objective mirror backwards and forwards but that only worsened the image. It became a blob. The crosshairs were out of focus as well.

I do wear spectacles. I have myopia (-2.5) and astigmatism (-1.75).

Any help is greatly appreciated. I would really want to rectify this issue.

Regards,

                 Prabal

[newbie alert]

Try to see if the bigger lens end has become un- screwed and if so refocus and then lock it down with the collar..

You can do this during the day but best done on a star

[andyboy1970]

My old 8x50 finder focuses by turning the objective end of the finder.

[prabal276]

Turning the objective lens did the trick this time! I tried it with my spectacles! 

thanks all!