I want to make a solar filter for my new 10" f4.8 OD250S, and I have asked Orion Optics for another dust cover to use.I will make the filter off axis, and use Astro-Solar safety film. But I am unsure what size hole to cut for the filter?I have the dust cover for my William Optics ZS66SD which I think is about 3 inches diameter.Is this a suitable size? for the 10" Or should I make the hole smaller or bigger?If anybody here can offer any advice, I would be very grateful. Paul
Cheers Callum,I will use the dust cover I have for my ZS66SD. I have been a casual solar observer on and off for a number of years, and I hope that with my new 10" Dob which is, after all so easy to set UP. It might encourage me to do more in the way of Solar observing.I might even be tempted to join the solar section!