PST mod - donor scope advice

[Merlin66]

Roel,

You are perfectly correct. I should have limited the answer to " interfere with the baffles....."

[Uplooker]

That's right. I used an old "Celestron Star Diagonal" to screw the PST eyepiece filters on. It must be said that the diagonal houses a prism, not a mirror. This is important because the threaded part on the PST filter is a a bit longer than that of the original Celestron eyepiece holder. When screwed in, the PST filter will hit the glass of the prism, causing astigmatism or misaligment of the prism! Therefore somekind of spacing ring is necessary: I used a simple rubber O-ring:

I used a Revelation Quartz Dielectric Diagonal 1.25" same as this one:-

http://www.harrisont...onal_1.25_.html

Luckily I was able to purchase a second hand one for less than half the price of a new one

Ian