Hi all,
I bought an Excursion, 8x36, looks as new, with case, in original box, all bits and bobs etc, perfect except for one thing, the center focus knob would not budge. Ok, update, slightly embarrassing, I did not try the obvious, it has a focus lock, however, there is still a problem, it will not focus using the focus knob, it now turns and the diopter side changes focus but it does nothing in respect of the focus on the left optic side, that does not focus at all ? If I look down the objective end, I can see the movement in the diopter side as I turn the knob, but the left side does not move at all. I knew it had a fault when I bought it, I got it cheap, with a view to trying to fix it, nothing to lose really at the price, but I was expecting it to be a problem with the diopter, as I have read this is often a problem on these. The diopter side however is fine, its the center focusing of the left side that's the problem. Now I have some good experience of working on Porro bins, but less so on roofs, so, before I charge in and start messing with it, I would be grateful if anyone has prior knowledge of this fault and any tips on dealing with it. It looks on first inspection that the small cap at the back of the focus knob with 2 tiny holes might be the place to start, however it might be an internal problem and not the knob.
Ben
I bought an Excursion, 8x36, looks as new, with case, in original box, all bits and bobs etc, perfect except for one thing, the center focus knob would not budge. Ok, update, slightly embarrassing, I did not try the obvious, it has a focus lock, however, there is still a problem, it will not focus using the focus knob, it now turns and the diopter side changes focus but it does nothing in respect of the focus on the left optic side, that does not focus at all ? If I look down the objective end, I can see the movement in the diopter side as I turn the knob, but the left side does not move at all. I knew it had a fault when I bought it, I got it cheap, with a view to trying to fix it, nothing to lose really at the price, but I was expecting it to be a problem with the diopter, as I have read this is often a problem on these. The diopter side however is fine, its the center focusing of the left side that's the problem. Now I have some good experience of working on Porro bins, but less so on roofs, so, before I charge in and start messing with it, I would be grateful if anyone has prior knowledge of this fault and any tips on dealing with it. It looks on first inspection that the small cap at the back of the focus knob with 2 tiny holes might be the place to start, however it might be an internal problem and not the knob.
Ben
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