Focusing issues on Skywatcher p150

[tjs247]

Well I've been having issues with my telescope.  I was looking at venus and I see like faint copies of Venus next to each other with actual Venus at the center.  I'm sure my scope.was collimated to. The mirror doesn't look quite good either, very dusty and a couple of smears somehow. So might just need a clean.

[CraigT82]

Sounds like internal reflections in the eyepiece or barlow if you're using one

[Louis D]

21 minutes ago, tjs247 said:

Well I've been having issues with my telescope.  I was looking at venus and I see like faint copies of Venus next to each other with actual Venus at the center.  I'm sure my scope.was collimated to. The mirror doesn't look quite good either, very dusty and a couple of smears somehow. So might just need a clean.

Have you tried other eyepieces to see if the ghosting changes or goes away?

[Mr niall]

Can u post any pics? Might help

[tjs247]

I'll try different eye pieces tonight. It's in the middle of the day so best I could do is a rough diagram. 

 

[Louis D]

7 hours ago, tjs247 said:

I'll try different eye pieces tonight. It's in the middle of the day so best I could do is a rough diagram. 

 

Interesting that the ghosts coincide with one of the secondary spider vanes' diffraction spikes' axes.  Perhaps the eyepiece is somehow picking up the bright diffraction spike and imaging it.  Try rotating your eye and eyepiece each relative to the focuser to see if anything changes.  Ideally, I'd say rotate the OTA and see if the ghosts follow it, but that would be difficult without rotating rings.  You could put an edge-on ruler across the front of the scope at a different angle from the vanes to see if that introduces a new diffraction spike and more ghosting.

[michael8554]

Venus is very very bright, so you may need a neutral density filter to cut down the internal reflections you're seeing.

Probably the same with other eyepieces, except maybe the most expensive 😆

Michael

[Mr niall]

On 26/03/2020 at 13:37, tjs247 said:

I'll try different eye pieces tonight. It's in the middle of the day so best I could do is a rough diagram. 

 

No I actually meant pics of your scope and mirror