Zeiss binocular

[Pawel582]

Hello, can some please tell me what kind of dirt is it (fungus?) and can i clean it somehow? How bad is it could it damage the lens if view is sharp and clean? It worth cleaning or sell how much they are worth in this condition?

[dweller25]

Point the binos to a bright part of the Sky (behind the Sun) to kill the fungus.

The coatings are probably damaged beyond just cleaning.

 

[Pawel582]

4 minutes ago, dweller25 said:

Point the binos to a bright part of the Sky (behind the Sun) to kill the fungus.

The coatings are probably damaged beyond just cleaning.

 

affects the image somehow? worth cleaning?

[dweller25]

The coatings are probably damaged beyond just cleaning

[DaveL59]

As David's said, try killing the fungus using sunlight but don't point them directly at the sun and then leave them unattended - you don't want to overheat the glass too much nor start a fire. You can use a UV light if you have one, usual precautions re looking at the light  etc apply. Also add a desiccant sachet into whatever you store them in to keep humidity down.

For cleaning, well that'd be nice but depends on your skills to dismantle and reassemble as it may well have found its way between the lenses in the eyepieces, on the prisms as well as the objectives. Then you'd really need to remove all grease etc and clean the casings. Finally you'll have to reassemble it all and then re-collimate so they are usable once again. Without the right equipment, collimating them won't be easy nor technically correct so you could end up with a nice clean bino that isn't usable at all other than as 2 monoscopes if you split them at the central hinge...

[Pawel582]

how long to put them in the sun to kill fungus?

[DaveL59]

A couple hours on a sunny window ledge should do it, perhaps repeat a couple times if you feel the need.

[Bruce Leeroy]

Could it be an optical cement failure?

[Pawel582]

51 minutes ago, Bruce Leeroy said:

Could it be an optical cement failure?

they dont have cement optic

[John]

39 minutes ago, Pawel582 said:

they dont have cement optic

The glass elements in binoculars are usually cemented together. The eyepiece and the objective lenses will comprise of more than one glass element and these are usually cemented together in binoculars. Cement in this context means a type of glue.

Edited August 3, 2023 by John

[JeremyS]

Certainly looks more like glue or some liquid rather than fungus 

[DaveL59]

Depending on age, canada balsam and there is an issue with lens separation but usually looks quite different and starts at the edge. Doesn't usually affect the view at least. Here's a pic of one of my TAL finderscopes that shows it.

 

The pics shown by the OP tho do look a little filament-like so quite possibly fungus. Of course by now it may well have etched the coatings and glass but if cleaned up may not impair the view. In fact it probably doesn't even now so just killing will be a good thing. If it gets really bad then sure, loss of contrast etc esp looking at bright objects will be the effect as well as worse damage to the glass. Will of course hit resale value

Edited August 3, 2023 by DaveL59

[Nakedgun]

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I had oculars on a used pair which looked like the OP's, and it turned out to be internal grease had somehow migrated there. After cleaning they were perfect.

 

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[Merkhet]

The first pictures look very much like the fungus I have recently removed from a 1950s camera lens. . sadly the fungus has etched the glass. I will try a film to see how bad it is.

I have a telephoto lens that has the cement breaking down.  This looks like lots of bubbles  on the glass.

Could the last picture be from sloshing the lens with lens cleaning fluid. Thereby allowing it to creep in around the edges with capillary action spreading it between the lens surfaces?

[johnbaz]

I bought a nice Opticron spotting scope through ebay and was really sad at how they arrived 😪

Was told it was balsamic failure or something like that, I had to send them back for a refund, It cost me around £20 to send them insured which I didn't get back from the seller so I really got a part refund!

 

 

John..

[Nakedgun]

15 hours ago, johnbaz said:

I bought a nice Opticron spotting scope through ebay and was really sad at how they arrived 😪

Was told it was balsamic failure or something like that, I had to send them back for a refund, It cost me around £20 to send them insured which I didn't get back from the seller so I really got a part refund!

 

 

John..

 

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The seller should certainly have disclosed this issue beforehand. I'd say you're entitled to a full refund.

 

 

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