Jenoptem diopter issue? (1 Viewer)

Bencw · Nov 4, 2015

Just wonder if anyone has any idea's on what I have done?. I stripped the ocular, diopter side of an 8x30 Zeiss Jenoptom as there was some mist / film inside, cleaned the lenses and took care to put all elements back exactly as they came out. My diopter is usually at between neutral and -1, and that was fine pre-clean. But now in order to focus properly the diopter setting has to be turned right around clockwise way past + markings , up at about 10 o'clock. I have cleaned plenty of Jenoptems but not encountered this before, they are pretty straightforward, can't figure it.

bfoutch · Nov 4, 2015

Not familiar with the Jena, but most of my porros have three tiny screws evenly spaced around the circumference that secure the knurled diopter ring in place, that, after you set the diopter where you want it, you can loosen these screws and slip upward the whole diopter ring and then turn it so the zero matches the center line and then slip it back down and re-tighten the three screws. I always do this to my binoculars so the zero is perfect for my eyes and I don't need to think about what number to set the diopter at.

On my Nikons, the three screws are under the eyecup, so that may be where yours are as well.

I hope it is as easy as this for you.

Bencw · Nov 4, 2015

bfoutch said:
Not familiar with the Jena, but most of my porros have three tiny screws evenly spaced around the circumference that secure the knurled diopter ring in place, that, after you set the diopter where you want it, you can loosen these screws and slip upward the whole diopter ring and then turn it so the zero matches the center line and then slip it back down and re-tighten the three screws. I always do this to my binoculars so the zero is perfect for my eyes and I don't need to think about what number to set the diopter at.

On my Nikons, the three screws are under the eyecup, so that may be where yours are as well.

I hope it is as easy as this for you.

Hi, many thanks,yes i'm familiar with those diopters, the Jenoptem does not have this, the knurled diopter ring screws onto the arm up tight and then the eyecup scews on top of it. But I appreciate the reply, I will have a look to see if I have somehow moved it or if it can adjust.

iveljay · Nov 4, 2015

Some front cell focussing cameras had multi-start threads. This caused the sort of effect if you mismatched the start position on reassembly. I don't know if bins use the same approach for fine adjustment, but it is usually fixed by rotating the threaded assemby through 180 from the start position you used.

WJC · Nov 4, 2015

iveljay said:
Some front cell focussing cameras had multi-start threads. This caused the sort of effect if you mismatched the start position on reassembly. I don't know if bins use the same approach for fine adjustment, but it is usually fixed by rotating the threaded assemby through 180 from the start position you used.

Bingo!

Bill

Bencw · Nov 5, 2015

Thanks Iveljay / Bill, will give that a go, looking at the assembly that seems most likely.

*That's it, job done, perfect, thanks guy's.

Jenoptem diopter issue? (1 Viewer)

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