MicrobeHunter.com Microscopy Forum

Hello I found fungus inside my newly bought Binoc head
you can see it in both left and right prisms

I tried to clean it but you cant reach it from front or behind when I remove the dovetail prism, it show no evidence of any growth
but looking through left and right prisms you can see different patterns so I know both side are affected
is this hopeless case or easy to clean up

cheers

Probably hopeless, I'm afraid.
I used to do environmental testing [including mould growth]
... The fugus can etch into the glass surface and/or anti-reflection coatings.

MichaelG.
.
Edit: I just found this: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3864060/

I'm not so pessimistic about fungus. Since it sometimes can be removed; "may etch into the glass surface and/or anti-reflection coatings", might be better. I'm of the opinion that it is the coatings that provide the substrate for fungal growth usually, and then depending on the glass used for the lens, it can invade the glass due to certain glasses ability to absorb water. Many heads do not have coatings on the prisms or mirrors and when it is limited primarily to a contaminating film on the surface, removal can be as much as 100%.

I'm certainly not going debate the nice distinction between 'can' and 'may'

MichaelG.

I have had to do with a lot of optics and have found fungus quite frequently. I would estimate that in 60% of the time I was able to remove the fungus without a trace, in 20% with minor traces that didn't render the optic useless and 20% hopeless cases. This may be different in places with different climate and of cause with different optics of cause.
The hopeless cases were part of those cases where spider net like patterns were visible. In really moist conditions glass can suffer a lot...
If you have just bought the tube head an it is not especially rare I would try to give it back if possible. Otherwise I would attempt to clean it. Post some images and we might be able to point you to a way into the covers of the tube head.

Bob

Ill do that if I can get it apart I went as far of removing the dovetail section which had a prism attached but did not see any further way inside the Binoc head
BTW the Fungus does cover the entire field of view in both sections so that leaves me with doubt it is recoverable esp that is is deep inside the prism assemblies.

Thank you to all the replies I really appreciate it

I would suggest that you post photos of the fungus and of the tube head. Sometimes you can remove most of the fungus without complete dismantling.

Here are some pictures of my progress cant seem to get the parts separate its as far as I see it will come
got the covers of Both sides but the L and R prisms are set in glue don't want to disturb that I also removed the spanner under the circular badge cover that allowed the halves to slide up/down but still does not separate.


cheers

What is the model number of the binocular head and can you post images of the fungus on the lenses?

Have no idea as there is no markings on unit whatsoever, all I know is it the version for the standard But I have a image of the fully assembled item for ID
very difficult to get good picture as eyes see it better but here it goes and both sides are the same amount infestation

If the left and right sides of the head are about equally affected, could it be that the problem is delamination, a result of deterioration of the balsam cement with time and environmental conditions, rather than fungus?

BTW I have read somewhere in the internet a claim, that some spores attack glass by releasing hydrofluoric acid (HF). This acid certainly etches glass, but an HF-producing organism?? is it true? does fungus contain fluorine?

Anyone ever taken a binoc down fully, my question how do I disassemble the prisms furthur at least removing the middle one that may be the surface I need to examine


Update: I have managed to get it a little further apart I found hidden spanner nut on the underside white plastic insert but even after unscrewing its the sames so no dice

I have not found any instructions on dismantling a Siedentopf binocular.

Have two, though mine are a little different to yours - will see if I can figure out a way to open it. Will post results (if any) later.

75RR wrote:I have not found any instructions on dismantling a Siedentopf binocular.

This may help: https://archive.org/details/APracticalG ... ollimation

Ron Green was very knowledgable and helpful.

MichaelG.

Hobbyst46 wrote:BTW I have read somewhere in the internet a claim, that some spores attack glass by releasing hydrofluoric acid (HF). This acid certainly etches glass, but an HF-producing organism?? is it true? does fungus contain fluorine?

It's worth reading the short paper that I linked in my first response ...

For convenience though, I will quote the opening paragraph:
In hot and humid climates it is common for fungus to grow on the surfaces of optical components. Airborne fungal spores settle on optical surfaces and develop into organisms that digest organic material, such as oils from fingerprints or lens coatings, producing hydrofluoric acid as a waste product. This acid in turn destroys any lens coatings and permanently etches the glass.

MichaelG.

MichaelG. wrote:

Hobbyst46 wrote:BTW I have read somewhere in the internet a claim, that some spores attack glass by releasing hydrofluoric acid

It's worth reading the short paper that I linked in my first response ...
For convenience though, I will quote the opening paragraph:
In hot and humid climates it is common for fungus to grow on the surfaces of optical components. Airborne fungal spores settle on optical surfaces and develop into organisms that digest organic material, such as oils from fingerprints or lens coatings, producing hydrofluoric acid as a waste product. This acid in turn destroys any lens coatings and permanently etches the glass.

Thanks, Michael, this is indeed the statement that I had read. So I began searching the internet for knowledge more details about HF-producing fungus.
Thanks also for the second link, about fixing the collimation. A focused (pun) explanation and manual!

Although the pictures are not highly detailed , your problem does not look like fungus to me. It looks like delamination. There are not many cemented joints in a head, usually. There may be one in the main incoming optical path, where a prism deviates the path to inclination,; that is likely in looking at the design of your head. A problem there will show up uniformly in each eyepiece. Next up the line is a joint in the beam splitter. A problem there will show up in one eyepiece; the one that receives the 1/2 of beam that goes straight through. The right angle reflected beam may show a ghost but often nothing or almost nothing.
A problem in both will show certain identical patterns in each but a more complex pattern with some differences in the eyepiece that receives the light with a linear pathway through the beamsplitter.

For anyone that has access to testing standards; the relevant ones are listed on this page:
https://www.cabi.org/services/microbial ... -problems/

MichaelG.

UPDATE:

I can now: CONFIRM the pattern is definitely isolated to just the left eyepiece prism, as after removing the lens element inside the dovetail it had some dirt or maybe fungus on the inner side I cleaned it with Denatured 99% and look sharp no etching then I again looked through opposing side and spider patterns were now only visible on left side port right prism is crystal clear
only problem is I dont see it coming apart as I have removed all the spanner rings and the halves wont seperate looks as the prisms are what is preventing the tube from moving any further.

Have you already cleaned every surface that can be reached so far? In some cases you can get into a gap with a folded tissue and with patience you can clean it up this way.

YES the telen lens or realy element that I removed had something on backside that clean up well but there still remains some on the inside on a prism surface that I can not reach unless I seperate the two movable parts

75RR wrote:I have not found any instructions on dismantling a Siedentopf binocular.

Have two, though mine are a little different to yours - will see if I can figure out a way to open it. Will post results (if any) later.

Update:
Made a start and then stopped. :(
This is a much more complicated disassembly than a Jentzsch. One that requires not only the right tools but some instructions. Sorry rs6000

This may help: https://archive.org/details/APracticalG ... ollimation

Ron Green was very knowledgable and helpful.

MichaelG.

Agree, very useful text. Most generous of him to to share this knowledge. Had not had a chance to use Ron Green's guide ... until now that is. After a partial disassembly/assembly I will have to collimate the binocular head.
Well, at least in this case there are instructions :)

Thank you all for your help on this issue It was most welcome, your outpouring of frendly and VERY Helpful support amazes me, this site is my new gem
now onto my Binoc head I have decided to drop it at this point as it is a lost case. The unit is not designed to be taken any further apart the prism assembly is cemented together inside the housing and will not separate unless the prism block is broken

Not instructions but an exploded view drawing:

https://www.dropbox.com/s/hfcvwv366uyzz ... 1.pdf?dl=0