Cannot focus with MPCC and Canon 300D (Rebel)

Hello,

I have a Canon Rebel (300D) on a 2" focuser (Newton 200/800 telescope).
The problem is that I cannot focus with the MPCC because the focuser
hits the tube. Is there a workaround?

Thank you

Chris

Chris,

It depends on which variety of focuser you have on your
Newtonian. Some of them have an extension on the 2"
adapter. If you have one of these, it may be very difficult to
reach focus with. I found that the Vixen 2" adapter for their
refractor focusers worked on mine, allowing it to reach
focus (it takes up essentially no backfocus), and did thread
onto my focuser. Can't guarantee it will on yours, as I used
this on a 200/1000 (8" F/5) Newtonian. Short of that, the
only other option I would be aware of would be to replace
the current focuser with a low profile Crayford unit. I know
it would be somewhat costly, but the improvement in finding
focus might be worth it. You could always use an extension
tube to find focus visually. Both Feathertouch and Moonlight
Instruments make focusers that shoudl fit your scope. There
may be a lower cost alternative out there.

Thanks, Tom Davis

"Chris" wrote in message
...
Hello,

I have a Canon Rebel (300D) on a 2" focuser (Newton 200/800 telescope).
The problem is that I cannot focus with the MPCC because the focuser hits
the tube. Is there a workaround?

Thank you

Chris

Tom,

THank you for your interest.

I have found this focuser
http://www.teleskop-service.de/Selbs...g.htm#TSOAZ2CN

But I am not sure it is really low profile... My Newtonian is a GSO
200/800
(http://www.teleskop-service.de/gssei...hau.htm#200800)

Cheers

Tom Davis wrote:
Chris,

It depends on which variety of focuser you have on your
Newtonian. Some of them have an extension on the 2"
adapter. If you have one of these, it may be very difficult to
reach focus with. I found that the Vixen 2" adapter for their
refractor focusers worked on mine, allowing it to reach
focus (it takes up essentially no backfocus), and did thread
onto my focuser. Can't guarantee it will on yours, as I used
this on a 200/1000 (8" F/5) Newtonian. Short of that, the
only other option I would be aware of would be to replace
the current focuser with a low profile Crayford unit. I know
it would be somewhat costly, but the improvement in finding
focus might be worth it. You could always use an extension
tube to find focus visually. Both Feathertouch and Moonlight
Instruments make focusers that shoudl fit your scope. There
may be a lower cost alternative out there.

Thanks, Tom Davis

"Chris" wrote in message
...

Hello,

I have a Canon Rebel (300D) on a 2" focuser (Newton 200/800 telescope).
The problem is that I cannot focus with the MPCC because the focuser hits
the tube. Is there a workaround?

Thank you

Chris

Could you use the TS M60-T2 adapter?
http://www.telescope-service.com/ATM...ers.html#foc2u
I suggest you ask Teleskop-Service.

Roger Persson

Since you already have a rather low profile focuser, your options are
reduced to: A) move the focuser closer to the primary, B) move the
primary closer to the focuser.

Good Luck.

Mitch

FWIW, I use a 300D on a Hardin Optical 200/800 with a Vixen Coma Corrector
and the Vixen adapter for the EOS cameras. The Vixen EOS adapter is two
pieces. A piece that screws into the focuser with a flange opening and
locking thumbscrews, and a second piece which attaches to the camera (the
actual T adapter), and fits to the flange on the focuser piece. The Coma
Corrector attaches to the scope side of the camera's piece of the T-adapter,
and sits down inside the focuser when the camera is mounted.

Here's some measurements I just made on my scope.
2.25" (Hardin stock) R&P focuser height
0.75" EOS adapter assemby with coma corrector installed
0.5" of focus travel with camera at infinity

Bottom line, it only adds the height of the T-adapter to the focuser. The
CC is completely hidden down inside the draw tube.

If you'd like to see some pictures, email me.

Works like a champ. Not sure what the issue is with the MPCC, unless it
screws into the draw tube and adds height. I've considered switching to the
TeleVue Photo/Visual-Paracorr. Like the Vixen, I think the TV unit will
"disappear" into the drawtube, as it is has a T-Thread, and becomes
analogous to a 2" nosepiece on your T-adapter, which you then simply insert
like an eyepiece. Unlike the Vixen, the Paracorr can also be used in my Dob
for visual use.

Hope that helps. Like I said, email me for pictures. I'm processing them
now.
- Stephen


"Chris" wrote in message
...
Hello,

I have a Canon Rebel (300D) on a 2" focuser (Newton 200/800 telescope).
The problem is that I cannot focus with the MPCC because the focuser hits
the tube. Is there a workaround?

Thank you

Chris