[ballaratdragons (Ken)]

As it is another cold rainy day I have spent several hours getting my 12" f5 dob just right.

I discovered through measurements and alignment that my 2ndry was out of wack.

I have set it at the recommended off-set - 1/10th of an inch off centre away from the focuser and 1/10th of an inch off centre towards the primary.

I have fully collimated it and the Cheshire reading is exactly centred and spot-on.

The clouds have parted so I took it outside to see how it would go on the daytime Moon.

I have posted a pic to show you what I now see with a 30mm 2" SuperView. It looks like this barlowed and un-barlowed. Then I tried a 25mm Plossl and got the same effect!

When I stepped up to a 15mm Plossl it went!!

I know it is the blurry reflection of the 2ndry and it is worst at perfect focus. I moved my eye around, away, closer, everything and it is visible at all times.

I have never had this problem before!!

What is causing this???