Carl Zeiss Jena 25mm Huygens

[badhex]

Bit of an update, I got a lens spanner and had a crack at removing the detritus.

So it seems that thankfully the eye lens is actually inside a brass tube which is threaded both inside and out, and has its own retaining ring inside, so no need to touch the lens itself. With a bit of gentle pressure this unscrewed easily. 

I noticed that all of the threads on the on the brass tube seem to be painted or coated with a matt black paint or coating, which could be what caused the issue - although they look like they might be how the EP was manufactured. 

I then turned the EP upside down and tapped out what I could, and most if not all of the larger pieces dropped out along with some black dust. I then used an air duster bulb to try to blow out any remaining dust or dirt. 

After some checking for any more dirt I went over the parts with more airdusting and a clean microfibre cloth to removed any dust, and reassembled.

A first look through the EP revealed more tiny bits of dust or paint flakes on the field lens! I did not see any whilst it was open, so possibly this happened during reassembly! I disassembled again, air dusted again, then reassembled - this time holding the EP upside down, in the hopes that any paint flakes/dust from the threads would stay there due to gravity, instead of dropping down onto the fields lens again. 

It seemed to work! I gave it a few taps to test if any dust was dislodged, but could not detect anything. 

I went over all of the non-glass outer surfaces with a tissue lightly dampened with water and a tiny spot of fairy, then again with a microfibre. 

I tested it out in my F7 TS102 and attempted a few rough shots through the EP with a phone. As you can see it is now nice and clean, as well as giving surprisingly good views in such a fast scope! Next stop is to try it under the stars. 

[Roy Challen]

So, have you tried this ep under the stars yet? It was a fine ep in my f16 achro, wondering how it fares in something more modern. I don't have any of my zeiss eps anymore or any other 0.956" eps, but that doesn't mean I wouldn't buy some in the future.

On 20/07/2022 at 10:27, badhex said:

Bit of an update, I got a lens spanner and had a crack at removing the detritus.

So it seems that thankfully the eye lens is actually inside a brass tube which is threaded both inside and out, and has its own retaining ring inside, so no need to touch the lens itself. With a bit of gentle pressure this unscrewed easily. 

I noticed that all of the threads on the on the brass tube seem to be painted or coated with a matt black paint or coating, which could be what caused the issue - although they look like they might be how the EP was manufactured. 

I then turned the EP upside down and tapped out what I could, and most if not all of the larger pieces dropped out along with some black dust. I then used an air duster bulb to try to blow out any remaining dust or dirt. 

After some checking for any more dirt I went over the parts with more airdusting and a clean microfibre cloth to removed any dust, and reassembled.

A first look through the EP revealed more tiny bits of dust or paint flakes on the field lens! I did not see any whilst it was open, so possibly this happened during reassembly! I disassembled again, air dusted again, then reassembled - this time holding the EP upside down, in the hopes that any paint flakes/dust from the threads would stay there due to gravity, instead of dropping down onto the fields lens again. 

It seemed to work! I gave it a few taps to test if any dust was dislodged, but could not detect anything. 

I went over all of the non-glass outer surfaces with a tissue lightly dampened with water and a tiny spot of fairy, then again with a microfibre. 

I tested it out in my F7 TS102 and attempted a few rough shots through the EP with a phone. As you can see it is now nice and clean, as well as giving surprisingly good views in such a fast scope! Next stop is to try it under the stars. 

 

[badhex]

2 hours ago, Roy Challen said:

So, have you tried this ep under the stars yet? It was a fine ep in my f16 achro, wondering how it fares in something more modern. I don't have any of my zeiss eps anymore or any other 0.956" eps, but that doesn't mean I wouldn't buy some in the future.

 

I haven't! With one thing or another I've neglected to get round to a proper look under the stars. I'm planning to try it with a Powermate as well to see how it performs in an effectively slower scope.