Burgess TMB 4mm Planetary Eyepiece.

[banjaxed]

My TMB 4mm eyepiece has not been used very often as it has been very disappointing. Checking my eyepieces earlier I looked at it again to see if it had any problems and on trying to move the cap from the barrel the whole lower section turned which I never noticed before. The barrel travels out approximately 2 cm and made me wonder if it is meant to be used for fine focusing. Can anyone confirm if this is the case please.

[lenscap]

23 minutes ago, banjaxed said:

The barrel travels out approximately 2 cm

Mine does that, though I estimate it moves about 1cm.

I assume it is a twist-up eyeguard used to achieve a comfortable amount of eye-relief.

[banjaxed]

3 minutes ago, lenscap said:

Mine does that, though I estimate it moves about 1cm.

I assume it is a twist-up eyeguard used to achieve a comfortable amount of eye-relief.

It isn’t the eye guard but the bottom section that attaches to the diagonal that moves out.

[lenscap]

14 minutes ago, banjaxed said:

It isn’t the eye guard but the bottom section that attaches to the diagonal that moves out.

Everything's relative. 😀

If you grasp the upper (largest diameter) section & twist the lower section clockwise then everything, including the eye lens, moves away from the upper section, which reduces the available eye-relief.

Edited November 28, 2020 by lenscap
added "available"

[Mr Spock]

Twist up eye cup. My 6mm does the same - the whole top section twists out.

[banjaxed]

9 minutes ago, lenscap said:

Everything's relative. 😀

If you grasp the upper (largest diameter) section & twist the lower section clockwise then everything, including the eye lens, moves away from the upper section, which reduces the eye-relief.

I see what you mean, looking closer the eyepiece lens moves away from the cup. When I first noticed I thought it was the barrel only moving but I see now the whole interior moves. Must have had this eyepiece for about 18 months and never realised it moved 🙄 😀

 

[Mr Spock]

I had mine years before I realised it did that - duh! 

[banjaxed]

31 minutes ago, Mr Spock said:

I had mine years before I realised it did that - duh! 

Glad it’s not just me 😀

[Louis D]

1 hour ago, banjaxed said:

I see what you mean, looking closer the eyepiece lens moves away from the cup. When I first noticed I thought it was the barrel only moving but I see now the whole interior moves. Must have had this eyepiece for about 18 months and never realised it moved 🙄😀

 

We have all had those moments in our lives.  We won't tell anyone if you don't. 😁