Focal reducer GSO RC10

[E_ri_k (Erik)]

Hi All. I'm after a focal reducer for my GSO RC10. Just wondering if anyone here with the same scope has one, and can let me know what would be a good choice?
Erik.

[RickS (Rick)]

Originally Posted by E_ri_k

Hi All. I'm after a focal reducer for my GSO RC10. Just wondering if anyone here with the same scope has one, and can let me know what would be a good choice?
Erik.

G'day Erik,

I have the Astro-Physics 27TVPH which works well and provides a fairly large image circle but you'll probably need some adapters to put it all together. The A-P CCDT67 is also a popular choice. It's more convenient and has a higher reduction factor but a smaller image circle.

Some tech details here: http://www.astro-physics.com/tech_su...r-techdata.pdf

Cheers,
Rick.

[E_ri_k (Erik)]

Cheers Rick, the AP reducer rings a bell. Think I might have looked at it before.
How does your's fit, does it slide in the focuser, then the camera thread on the other end, with different spacers giving different reductions?
Thanks for the info!

[RickS (Rick)]

Erik,

The 27TVPH has A-P 2.7" threads on both sides and screws into the focuser. The CCDT67 slides into a 2" adapter so that's probably what you're thinking of. Both reducers give a variable reduction ratio depending on distance from the sensor (image circle varies with distance too). The link I gave specifies the calculations for both reducers.

Cheers,
Rick.

[E_ri_k (Erik)]

Thanks again Rick, yeah I saw the calculations on the page. Looks what I'm after.

.75 would be a good reduction I think. I'll have to leave it a bit. $250 for the reducer, + adapters..

Thanks for pointing me in the right direction though. I was looking at the $50 GSO reducer, but I don't know how good it will be.

Erik

[cventer]

I am pretty sure I have an AP CCDT67 that I only used twice with my RC10 that I no longer use.

PM me with an offer If you want it. They are between $165 and $185 new from USA plus shipping.

Cheers
Chris

[naskies (Dave)]

I've used the CCDT67 reducer successfully with my STF-8300M camera + FW + OAG.

The CCDT67 has a 2-inch male filter thread that screws onto the front of my Baader 2-inch nosepiece, and then it just goes into the focuser as normal. Oddly enough, the spacing was exactly right to give me 0.67x reduction (confirmed via astrometry). I've stopped using it though because I don't have enough back focus for the STF-8300M plus adaptive optics.

What chip are you imaging with? The 27TVPH is more of a challenge to attach, depending upon which brand focuser you're using.

[E_ri_k (Erik)]

Originally Posted by cventer

I am pretty sure I have an AP CCDT67 that I only used twice with my RC10 that I no longer use.

PM me with an offer If you want it. They are between $165 and $185 new from USA plus shipping.

Cheers
Chris

Thanks for the offer. I'll be in touch.

Originally Posted by naskies

I've used the CCDT67 reducer successfully with my STF-8300M camera + FW + OAG.

What chip are you imaging with? The 27TVPH is more of a challenge to attach, depending upon which brand focuser you're using.

I'm Imaging with a QHY 10 and using a 2.5 inch moonlight focuser.
Thanks.
Erik

[binofied]

I have just got the TS2.5Flat from Teleskop-express . It can screw into the 68mm top on newer Moonlite focusers. I then have a 50mm extender tube / adaptor from that to my SBIG STL-11000 camera. The spacing is important I had it 15mm farther away in another configuration using the old GSO focuser and the corners were still not right. Now first tests are very good. The other issue was the Moonlite focuser standard issue was to long, Ron made me a special low profile one swapping out the main 2.5" body for a shorter one and a low profile flange at the bottom. I now have 15mm spare back focus to play with.

[binofied]

Sorry, just re-reading the first post, this is a flattener only not a reducer