That pretty cool Mark, Id be wrapped with that !
You say 250mm apeture, F/Ratio ? & with a barlow/s, I assume yes be it a guess 4x ?
Got some good detail & colours there, Beauty
Bob, Scope is 250mm F16 (4m focal length) used with a barlow at about 2.3x so effective focal length is about 9m at F36. I would probably prefer a little bit shorter/faster but with my current barlow arrangement this is the shortest/fastest I can get.
Bob, Scope is 250mm F16 (4m focal length) used with a barlow at about 2.3x so effective focal length is about 9m at F36. I would probably prefer a little bit shorter/faster but with my current barlow arrangement this is the shortest/fastest I can get.
Mark
250mm @ F16, unreal, you'd need two people to carry it, one at each end with walky talky's F16 would certianly aid in getting planet resolution, perfect scope in a lot of respects for the job. Intreguing to know, assume its a mirror, was custom made ? Ive never heard a scope of these dimensions, not doubting you at all, and if you get a high alt planet in steady conditions with it, well, Mind boggles ! !
Cheers for them specs
250mm @ F16, unreal, you'd need two people to carry it, one at each end with walky talky's F16 would certianly aid in getting planet resolution, perfect scope in a lot of respects for the job. Intreguing to know, assume its a mirror, was custom made ? Ive never heard a scope of these dimensions, not doubting you at all, and if you get a high alt planet in steady conditions with it, well, Mind boggles ! !
Cheers for them specs
Sorry Bob, I have perhaps misled a little, the scope is not a Newtonian, it is a Cassegrain style or more correctly a Dall-Kirkam so the tube is only about a meter long.
why have you attached a vacuum cleaner to your eyepiece for mark?
pat
To keep the eyepieces clean, works much better than a broom
(it is for vibrationless cooling of the primary - there is a fan at the end of the tube, and it can work at full speed with no visible vibration at the eyepiece/camera end)
To keep the eyepieces clean, works much better than a broom
(it is for vibrationless cooling of the primary - there is a fan at the end of the tube, and it can work at full speed with no visible vibration at the eyepiece/camera end)
bugger me!! to the nth degree or what ha ha!
how rude of me anyhow mate the pic is great firstly!
pat
Sorry Bob, I have perhaps misled a little, the scope is not a Newtonian, it is a Cassegrain style or more correctly a Dall-Kirkam so the tube is only about a meter long.
Thanks Pat for your question and thank you Bratislav and Clive for the spot on answers.
The vacuum cleaner hose certainly does attract attention!
Credit to the scope's air venting system goes to the maker of the telescope who I bought it off some years ago. If he is listening he may like to comment.
Ok, I'm responsible for combining the vacuum cleaner with the telescope.
I wanted to reverse the air flow within the tube but I did not want to have the fan hanging of the back and introduce vibrations. I was using a flimsy mount with the scope and it did not take much to get it vibrating.
The scope I'm using these days is larger, with enough mass to cope with 3 smaller fans mounted directly on the back plate.
F16 would certianly aid in getting planet resolution, perfect scope in a lot of respects for the job. Intreguing to know, assume its a mirror, was custom made ? Ive never heard a scope of these dimensions, not doubting you at all, and if you get a high alt planet in steady conditions with it, well, Mind boggles ! ! 
