camera adapter recommendations

i have a camera adapter from meade. the one that has a adjustable length and
allows a eyepiece to be locked into the unit prior to the camera t-ring. i
am finding that the eyepiece size is limited. anyone know what the
limitations on this adapter are? what eyepieces will work... i was able to
put a 20mm kellner into it, but my 25mm sirius plossel won't fit. anyone
have any experiance with this adapter? BTW it is a 1-1/4" adapter.
thanks
john

In message , shawn o'deal
writes
i have a camera adapter from meade. the one that has a adjustable length and
allows a eyepiece to be locked into the unit prior to the camera t-ring. i
am finding that the eyepiece size is limited. anyone know what the
limitations on this adapter are? what eyepieces will work... i was able to
put a 20mm kellner into it, but my 25mm sirius plossel won't fit. anyone
have any experiance with this adapter? BTW it is a 1-1/4" adapter.

The limit is determined by the ID of the adapter tube. I think it is a
fraction larger than the Meade SP eyepiece OD but I use the other Meade
prime focus adapter in combination with a set of extension tubes one of
which has been reamed out to match the 1.25" eyepiece fitting.

Extension tubes are very cheap second hand and you don't even need
working aperture linkage for astro work. These things tend to accumulate
in proper photo dealers junk baskets for under a fiver.

Using extension tubes with eyepiece projection to increase the drift
length and magnification with the same eyepiece is probably more
convenient anyway.

Same trick applies to 2x and 3x teleconverters too. Took me a while to
find a decent 1.4x converter at a price I was prepared to pay.

Regards,
--
Martin Brown