Antares f/6.3 focal reducer

[themos]

Hello

Does anyone know what the correct spacing for this is? I will be using an EOS DSLR (and a Meade OAG) and I'd like to know how much space I should leave between the reducer and the camera. If anybody is already using this bit of kit, could you share what you know?

Thanks!

[SpookyKatt]

This sgl thread and cloudynights thread seem to indicate

the Antares focal reducer spacing should be around 82mm.

http://stargazerslounge.com/discussions-eyepieces/166743-sct-6-3-focal-reducer-ccd-distance.html

Telescope Reviews: f/6.3 reducer spacing for SCT

Kathleen

[themos]

Thanks! Should I measure from the glass surface or the top of the fitting though? If I measure from the glass, I have it at 108mm (100mm from the fitting). There's an OAG in the middle that takes 45mm, the EOS T ring takes another 11mm and the depth of the sensor in the camera is 44mm.

Hmm, I may have to use a lower profile OAG.

[themos]

or get the celestron reducer with its 105mm spacing...

[themos]

Oh dear, I've been measuring from the camera side of the glass but apparently I need to measure from the telescope side of the glass ! That's even worse!

[SpookyKatt]

Yeah I had a problem getting the Antares focal reducer working with

a brightstar OAG and have had to try a different path instead.

Hope you have better luck than me.

Kathleen

[themos]

This Antares seems to have a weird 40mm thread on the camera side. It fits the Meade OAG but it won't fit anything else I have kicking around! I realize now that the mismatch in spacing with the way I was running it explains the very non-flat field I was getting.

[SpookyKatt]

I think its a sct thread on each side. I know with the brightstar

I needed an additional sct to t-thread adaptor in place which pushed

the spacing out. I'm tempted to try a lower profile sct to t-thread

adaptor but think that will still be too big.

[themos]

I think you're right, it's an SCT thread either way. I remember now that we used to put a Crayford focuser on its camera end. I must see if I can borrow a Celestron f/6.3 reducer from someone and try it out.