Zeiss Jena modification? (1 Viewer)

Can the hard eyecups be safely removed or filed down to increase eye relief?

Robert Ellis said:

Can the hard eyecups be safely removed or filed down to increase eye relief?

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They unscrew. Don't even think about filing them. Most of those eyecups are made of a hard bakelite or some similar material. You will end up with a badly botched up job. However, a skilled machinist with a lathe will be able to do wonders for you. I've seen tons of Jena's where a missing or broken eyecup was replaced with a new one made of brass or aluminum. You might gain a few mm of eye relief...

If I unscrew them and fit a flat brass ring, would that not givc 2 or 3 more mm? I have read that the stated original relief was about 9mm, was that measured from the end of the cups or from the ocular?

Different models had different eye relief. You can be sure the 9mm was measured from the glass. None of them would have had 9mm beyond the end of a hard eyecup. The eyecups unscrew easily enough, but then your eyeglass lens will be in contact with the metal eyepiece and the eye relief might still be too short. As I recall CZJ had a flat rubber eyecup for eyeglass wearers available as an accessory item before they finally switched to fold downs. Docter Optics might still have some of the fold down eyecups as replacement parts.

I saw your post about buying these binoculars on eBay. Keep in mind that after WWII CZJ made only a few premium quality binocular models in the same class with Zeiss in West Germany. Those rarely turn up on eBay and are expensive when the they do. Most of the ebay offerings are the cheap stuff that sold for less than $100 new. I bought a Deltrintem in the late 80's and found it to be crudely made and optically mediocre, in no way the equal of a Nikon 8x30 E. Still if a late example of one of those came along in mint condition with T3M multi-coating, fold down eyecups and a leather case it might be reasonable to pay as much as $100.

henry link said:

I saw your post about buying these binoculars on eBay. Keep in mind that after WWII CZJ made only a few premium quality binocular models in the same class with Zeiss in West Germany. Those rarely turn up on eBay and are expensive when the they do. Most of the ebay offerings are the cheap stuff that sold for less than $100 new. I bought a Deltrintem in the late 80's and found it to be crudely made and optically mediocre, in no way the equal of a Nikon 8x30 E. Still if a late example of one of those came along in mint condition with T3M multi-coating, fold down eyecups and a leather case it might be reasonable to pay as much as $100.

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Henry - I think your assessment of CZJ bins is a little harsh. In my experience, build quality of CZJ binoculars made in the late 50's until the early 70's was actually quite good, and that the later versions (unfortunately, the ones with multicoating and rubber eyecups) were generally the disappointments. I have owned over the years a 10 x 50 Deltrintis, 7 x 50 Binoctem, 8 x 30 Deltrintem, 8 x 50 Octarem and 10 x 40 Notarem. The Deltrintem, made in the mid-80's, was, as you experienced, mechanically and optically poor, while the Notarem, also a mid-80's Eisfeld-made example, was better optically, but also poorly assembled from substandard materials. The Deltrintis and Binoctem, by contrast, were both made in the mid-60's, were each optically excellent, and the Octarem, which I still own and which was made in the late 80's, is a gem. Supposedly, the Octarem, Dodecarem and later Nobilems had improved prism housings, but the other CZJ porros were notorious for their inability to hold collimation when actually used in the field. Still, $100 seems awfully low, even for the dogs (heck, the hard leather "luxury case" is worth that)..

Well, if I could never get more than 9mm of eye relief out of them, there is no point. They would have made for fun backups. Strutting out onto Point Reyes with ugly old, but Zeiss, binoculars would be funny in the sea of ELs and FLs.

Chartwell,

I agree with you about the quality of the Octarems and the leather cases. I also have an Octarem from the late 80's. Leather cases like that just aren't available at all now and if they were they would probably cost $150-200. I kick myself in the rear everytime I recall buying an 8x50 Nobilem "super" in 1985 and then having no better sense than to trade it a few years later for a non phase-coated 10x40 Dialyt, the worst deal I ever made.

Well, if I could never get more than 9mm of eye relief out of them, there is no point. They would have made for fun backups. Strutting out onto Point Reyes with ugly old, but Zeiss, binoculars would be funny in the sea of ELs and FLs.

Robert

Whilst at a South Lincolnshire hide in the UK recently i "swapped" a Zeiss 10 x 50 Jenoptem mc with a Swaro EL 8.5 x 42 for about an hour or so
I enjoyed the Swaro's and thought the slightly lower mag was very useable however the interesting thing was that the fellow birder i "swapped " with was very surprised by the Jenoptem view and actually commented that despite the "look" and weight they were optically very good
His only issue was with possible shake (10 x) and eye relief
Its just food for thought i suppose !

Regards
rich T