1. Photos (1) and (2) can be said to show the 'back' view of the Bushnell 7x26, while Photos (3) and (4) show the 'front' view. The diopter ring is shrouded by an elevated section of bodywork in front view.
So the diopter ring is accessible.
2. I have de-frozen the diopter ring.
I recut the middle piece of inner tube from a length of tube of slightly greater diameter than the diameter of the original piece so that it fitted less tightly. I then reassembled the pieces of inner tube on the diopter side (and also, in order to match sides, the non-diopter side).
In fact the diopter ring is made to rotate less freely by the bottom edge of the first piece of inner tube (ie the piece that freezes the eye cups in the up position) pressing down upon it.
So when fitting the middle piece, I must have caused the freeze by dragging the bottom piece a little further down at the same time.
The lesson learned is that one can't have enough lengths of inner tube of different diameters.
Local cyclists will have to favour me by having more punctures!
Last edited by Stephen Prower : Wednesday 20th July 2016 at 22:22.