Astro Physics CCDT67 Focal Reducer

[pjphilli]

Hi

I see from an old thread that IinS members have had some experience with the Astro Physics CCDT67 focal reducer. Apparently this is suitable for using on GSO RC scopes. I would like to attach one to my 200mm
f8 GSO RC scope.

I would like to hear of experience with using this focal reducer.

Also where is a good supplier - is there one in Austraia?

Cheers Peter

[allan gould]

Bought mine from O/S and it works perfectly on a 10" GSO RC.

[lazjen]

I've got one for my RC10. It works well, but as I use a full frame Canon (the 6D), I think I get very slight vignetting with it.

From memory, to get focus, I have to place it very close to the camera, just after the OAG.

This post has made me realise that I probably should have taken more notes about my setups - I was using it so regularly before summer hit that I just remembered everything. When I eventually get out again I'll have to relearn everything. :)

Edit: ordered from overseas. I don't know of anywhere in Oz to get it.

[Shiggy]

I find the CCDT67 to be a great reducer. Not only does it reduce with plenty of backfocus (85mm) and variable reduction if you are off, but it also flattens the field somewhat up to 29mm diameter (fine for many ccds).
It is able to attach to a 2" nozzle allowing it to enter the drawtube.
For the low price this is very good value.
I bought mine from here (http://www.teleskop-express.de/shop/product_info.php/language/en/info/p4955_Astro-Physics-CCDT67-0-67x-Reducer-2----z-B--fuer-GSO-RC.html).

[pjphilli]

Thanks All for your encouraging advice.
Chris - The field diameter for this fr is 29mm and a full frame Canon has
a diagonal width of 42mm so I suppose you would get a bit of vignetting
around the corners. My Canon 400D has a diagonal width of 27mm which
is just inside the 29mm limit.
Shaun - The 85mm backfocus will suit me fine as I know that my 200mm RC will accomodate this with some forward focus left (with all the RC spacers removed). Good site - I will probably purchase the fr from them.
Cheers Peter

[RickS]

If you want a bigger image circle there is always the option of the larger 27TVPH reducer. I used one very successfully with a GSO RC10.

Cheers,
Rick.

[lazjen]

If I don't switch to a CCD camera soon (i.e. persist with the 6D), then I might look into the larger reducer. I'll live with the vignetting for now when I use it.