[Arthur Alchin (Arthur Alchin)]

Have a MEADE DSI and the IR filter appears to be a little dirty.

Doing some terestial shots it looks like some raindrops on the computer screen.

Have tried a little isopropyl alcohol 70% with a lens tissue but not sure if it has done the trick. has anybody got any simple ideas that may work.

Am going to A/ Camp at lostock this week if anyone can help.

Also 2 questions: (A) is the IR filter needed all the time ?? (B) one american source suggested replacing with a screw in IR filter to go into the end of the DSI tube. Has anybody got any thoughts on the subject?

Arthur