Stephen Prower
Well-known member
Summary: I describe user modifications to a new binocular with the object of: 1) Improving the feel of the focussing wheel; 2) Locating the eyes consistently at the point of eye relief
I have started to customise a modern Roof binocular that has adjustable eyecups. I have so far achieved two improvements to 'ergonomic' aspects of the performance of the binocular that disappointed me. (1) The focussing wheel after an hour or so became uncomfortable to use. (2) I was not fully happy with the view through the binocular. I suspected that I was not locating the eyes consistently at the point of eye relief.
I attach a photo of how I modified the focussing wheel and eyecups.
In case it is useful to anybody, I go on below as I have said to describe and explain the modifications.
I apologise if I sometimes repeat what I have said in previous posts on the Forum on the subject of using bicycle inner tube to bulk out the width of binocular eyecups.
Changing the feel of the focussing wheel
The edge of the focussing wheel of the Roof had a coarse 'grippy' rubber surface pattern. It became unpleasant to use after half-an hour or so's birdwatching. It also on one occasion caused the end of my finger on the wheel to go numb.
I therefore, as I have done before with old Porros, cut a section of bicycle inner tube, and sleeved it over focussing wheel.
The inner tube that I used was an ordinary--in Britain--Butyl rubber tube sized to fit a mountain bike tyre of 2.125 inch maximum section.
A tube made out of thinner rubber, or a tube sized to fit a tyre of 2.3 inch maximum section (which seems to be the next common size up), would probably have fitted more easily.
I don't report the result of a long term test. But the inner tube seemed to do the trick. The focussing wheel became more comfortable to operate, while at the same time continuing to provide a good grip.
Locating the eyes at the point of eye relief
A binocular should naturally come to the eyes with the eyes located at the point of eye relief.
When the binocular is thrown to the eyes, the location of the eyes above the ocular lens is not only determined by the elevation of the eyecups, but also by the most comfortable fit of the binoculars to the face as determined by the width of the eyecups.
In order to achieve a consistent location of the eyes at the point of eye relief, one must therefore match the figures of the elevation and the width of the eyecups individually for each user.
My method of doing so is 'Suck it and see'.
So I tried increasing the diameter of the eyecups by sleeving over them a doubled over section of inner tube sized to fit a mountain bike tyre of 2.5 inch maximum section. The inner tube increased the diameter of the eyecup from 40mm to 43mm, which I know from experience to be a comfortable diameter for me.
Ordinarily I would then have gone on to try different figures of the elevation of the eyecups, and when I got a good result for a particular figure, have frozen the eyecup in position with a rubber band of suitable width and thickness cut from more inner tube.
But I found that with the eyecups fully extended, I seemed to have hit the spot. I was already satisfied with the view.
Stephen
I have started to customise a modern Roof binocular that has adjustable eyecups. I have so far achieved two improvements to 'ergonomic' aspects of the performance of the binocular that disappointed me. (1) The focussing wheel after an hour or so became uncomfortable to use. (2) I was not fully happy with the view through the binocular. I suspected that I was not locating the eyes consistently at the point of eye relief.
I attach a photo of how I modified the focussing wheel and eyecups.
In case it is useful to anybody, I go on below as I have said to describe and explain the modifications.
I apologise if I sometimes repeat what I have said in previous posts on the Forum on the subject of using bicycle inner tube to bulk out the width of binocular eyecups.
Changing the feel of the focussing wheel
The edge of the focussing wheel of the Roof had a coarse 'grippy' rubber surface pattern. It became unpleasant to use after half-an hour or so's birdwatching. It also on one occasion caused the end of my finger on the wheel to go numb.
I therefore, as I have done before with old Porros, cut a section of bicycle inner tube, and sleeved it over focussing wheel.
The inner tube that I used was an ordinary--in Britain--Butyl rubber tube sized to fit a mountain bike tyre of 2.125 inch maximum section.
A tube made out of thinner rubber, or a tube sized to fit a tyre of 2.3 inch maximum section (which seems to be the next common size up), would probably have fitted more easily.
I don't report the result of a long term test. But the inner tube seemed to do the trick. The focussing wheel became more comfortable to operate, while at the same time continuing to provide a good grip.
Locating the eyes at the point of eye relief
A binocular should naturally come to the eyes with the eyes located at the point of eye relief.
When the binocular is thrown to the eyes, the location of the eyes above the ocular lens is not only determined by the elevation of the eyecups, but also by the most comfortable fit of the binoculars to the face as determined by the width of the eyecups.
In order to achieve a consistent location of the eyes at the point of eye relief, one must therefore match the figures of the elevation and the width of the eyecups individually for each user.
My method of doing so is 'Suck it and see'.
So I tried increasing the diameter of the eyecups by sleeving over them a doubled over section of inner tube sized to fit a mountain bike tyre of 2.5 inch maximum section. The inner tube increased the diameter of the eyecup from 40mm to 43mm, which I know from experience to be a comfortable diameter for me.
Ordinarily I would then have gone on to try different figures of the elevation of the eyecups, and when I got a good result for a particular figure, have frozen the eyecup in position with a rubber band of suitable width and thickness cut from more inner tube.
But I found that with the eyecups fully extended, I seemed to have hit the spot. I was already satisfied with the view.
Stephen
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