Quote:
Originally Posted by h0ughy
crickey! that is a monster of a teleconverter, I have never seen one like that, I have the straight 2 times Sigma DC teleconverter, will that do the same job for me? was focus easily reached? does the exposure time increase as as result? have I asked too many questions?

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Hi H0ughy
It is a very old (25 yrs) Teleplus Macro 7 element converter. The really nice thing about it is that when I get rough focus with the WO focuser, I then lock the WO focus lock and move to the teleconverter, which has a helical focusing ring that you can see in the photo. This “built in” focus ring is there for use with the macro settings of the teleconverter and it makes it so much easier to get best focus.
Yes - the exposure time doubles. If the native lens is at say, F8, then adding the teleconverter will make it an F11 system, so you do "lose" light. The image posted was 1/500 sec at 200ASA.
As your teleconverter probably does not have a focus ring, you will have to do all your focusing with the 'scope focuser. But other than that, your x2 converter should behave the same as mine; probably better if it is ED glass?
Cheers
Dennis