Raci finder - a question

[hayzi111]

Hi folks. Just inherited my first raci 9x50 finder with a 12" dob i aquired 2nd hand. It seems like it has a socket for a 1.25 ep so I'm a little confused. Should it not have a permanant piece in there as with a straight through finder? Wondered if I was missing a piece. If not what focal length ep would you guys advise using for just general star hopping? Would low power 40 mm be best as I would like as wide a view as possible. Cheers

[physicus]

I think the 9 x 50 finder lenses have a focal length around 165mm, so 165 / 40mm eyepiece = 4x ish, which is maybe a bit low (i.e. it's not 9x !).  A 20mm to 30mm probably better I would say.

[Ruud]

If it is a 9x50 it should have an eyepiece already, otherwise it would just be a 50mm OTA.

So you may have an eyepiece missing. If a 1.25" eyepiece fits, I'd go for a not-so-expensive 32 mm Plössl, probably the GSO 52°, as it too will give the widest possible view in the 1.25" format.

Do you have a picture of the finder?

[Dave In Vermont]

I agree with Ruud - check to see if it fits a 1.25" eyepiece. If yes - try a 32mm. Maybe 25mm. See what works best. If it is smaller than 1.25" - it's missing it's often built-in eyepiece, which are of a smaller dimension.

Dave

[laudropb]

Certainly the Skywatchers 9x50 has a fixed eye piece.

[Hitman77]

Thanks guys - sorry for late reply. Been away for a few days. Had a wee gap in the clouds last night and had the scope and finder out in the back garden. I popped a 25mm ep in the raci but it was totally out of focus and there is no focuser on it . I thought I would take a few pictures and post them as requested but I can't seem to find a way to upload these to my message or profile. I'm sure I am being a bit dim but as a new member is there restrictions in place to stop folk uploading pics?

[brantuk]

Is there a make and model written on the finder somewhere. With that info we may be able to identify it and find what eyepiece it's supposed to take. The raci's in my experience usually have a locking ring behind the objective cell which enables the front lens to be focused by turning in or out (then re-locking it). Hth

[Skipper Billy]

Hitman77 are you the original poster - first post was from Hayzi111 - I am confused ! (Which isnt unusual !!)

To post an image click in the bottom right corner 'More reply options' - then bottom click  'choose file'  - then click 'attach this file' and it will upload.

[hayzi111]

Ha ha - yes I am Hitma77/Hayzi111 managed to lose my login details. Sorry for confusion. I will post pics of the finder tomorrow once I get in from work. Unhelpfully there are no details on the finder........really appreciate yer help guys.

[Hitman77]

Hi guys and thanks to Skipper Billy for helping me upload these raci pictures. Had a good look at it but defo no information about the maker or what size but I believe it's a 50mm lens. Popped the 25mm ep back in and began pulling it out slowly to see where the focus point was. It appears to reach perfect focus about 5mm out of the diagonal. Is there some piece I could buy to pop in there to achieve focus or should I maybe buy a 30/32mm ep and see if that would work?

[Dave In Vermont]

Is there a lens in the front of it? Or are we looking at a hollow tube? If it's a hollow-tube, it belongs in the recycling-bin/trash-can.

Dave

[Ricochet]

There must be a way of focusing it (even if there isn't enough room for manoeuvre with your current EP). What does the little thumbscrew by the diagonal do? Can you pull/twist the diagonal out a bit?

Also, what make/model is the scope it came on? Does it look like it was an original accessory?

[Hitman77]

Yes there is a lens in the front - It did not occur to me to pull the diagonal out a wee bit. Just tried it and with the diagonal almost out completely and the ep pulled up a bit I can get it to focus. Thanks for all your advice guys. I'll buy a 32mm to give a wider field of view and I shall be all set. 

[Ruud]

Wonderful !!

Good luck with the finder.