Tal eyepieces

[Zachariah]

I have a tal1 scope dated about 1993, the supplied eypieces of 25 and15 mm will not fit any other scope as they are slightly too large. Other 1.25 eps are a loose fit and will not focus without a tal barlow. Does anyone know why this is?

[AndyH]

Simply because Tal decided to do it that way, in their early scopes The eyepieces and focusers were a 32mm fitting, rather than 31.75mm.

A bit of electrical tape or similar, wrapped around a 31.75mm eyepiece is a cheap n easy fix. There are other methods, which involve a bit of engineering.

The mirror does need to be moved up in it's cell, for std 31.75mm eyepieces to reach focus. This may sound daunting, but it only involves changing the mirror cells springs and two types of setscrews. There's a thread or two kicking about on sgl, regarding this. The key to it being successful, is strong springs.

Whilst I have a slighty newer Tal 1 with a std focuser, I moved my mirror up to let me use my Speers 5-8 zoom, as it needs a fair bit of infocus. So far no issues with the mirror shifting and it's been altered for quite a while now.

Andy.

[heathenwoods]

Hi Zachariah, I've just moved my mirror up the tube and it worked just fine - focus from standard eyepieces! I have a couple of sets of the necessary screws/bolts etc if you need them: PM if you do.