Reichert Polyvar Microscope
Reichert Polyvar Microscope
Hi Everyone,
I recently acquired a Reichert Polyvar Microscope in fairly good condition and looking forward to using it for identifying and documenting mushroom spores. Everything about it works great, but I just can't seem to figure out why the left eyepiece is exhibiting a blue tint/cast. I can confirm that it's not the eyepiece itself but somewhere in the binocular tube. Would anyone know what causes this, if it's normal or if there's a way to resolve it? Your insight and help is much appreciated!
I've attached some rough photos I took with my phone. I plan on attaching my Canon 7d, but that's for another post.
I recently acquired a Reichert Polyvar Microscope in fairly good condition and looking forward to using it for identifying and documenting mushroom spores. Everything about it works great, but I just can't seem to figure out why the left eyepiece is exhibiting a blue tint/cast. I can confirm that it's not the eyepiece itself but somewhere in the binocular tube. Would anyone know what causes this, if it's normal or if there's a way to resolve it? Your insight and help is much appreciated!
I've attached some rough photos I took with my phone. I plan on attaching my Canon 7d, but that's for another post.
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Re: Reichert Polyvar Microscope
slight differences in color between eyepieces have been reported and aren't too abnormal.
This, though, looks pretty extreme. try removing the head, removing the eyepiece and shining a light through the bottom so you can examine the prisms to see if there's anything on them.
This, though, looks pretty extreme. try removing the head, removing the eyepiece and shining a light through the bottom so you can examine the prisms to see if there's anything on them.
Re: Reichert Polyvar Microscope
Thanks for your response. I did have a quick look at the prism with the eyepiece removed and that same blue tint is on the prism, but I don't understand why it's there or what's causing it. If anyone thinks it's worth taking the binocular tube apart to have a closer look at the prism, I can see if I can do that.
You can see both the left and right side of the prism without the eyepieces in this photo.
You can see both the left and right side of the prism without the eyepieces in this photo.
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Re: Reichert Polyvar Microscope
Also, if you look carefully, you can see the same shape on the RIGHT eyepiece but it looks like a more faded. It's very subtle but you can see that it's the exact same shape in the same orientation. Perhaps it means it's caused somewhere beyond the binocular tube?
Re: Reichert Polyvar Microscope
You might try to shine a flashlight through the eyepiece tubes and compare the output at the other end. That structure on your first photos - is that a piece of paper in the object plane?
Sometimes differences from left to right come from delaminated prisms, but this here looks very special to me.
Bob
Sometimes differences from left to right come from delaminated prisms, but this here looks very special to me.
Bob
Re: Reichert Polyvar Microscope
Yes that is just a piece of paper on the other end.
I did as you suggested and illuminated the eyepieces with a flashlight. I put a piece of mylar on the object plane and put my phone below in 'selfie mode' so I can see what it's taking a picture of. Apologies for the low res but you can clearly see the same shape on both sides. The left side is the usual blue tint (more pronounced) but you can see a subtle reddish tint on the right side that is also the same shape.
Would there be any reason for making one side blue and the other red? Also, perhaps fungus in the binocular tube is responsible for the light making that shape?
I'm new at this, I really appreciate your guidance.
EDIT: I added a second photo where I removed the objective turret, put a piece of paper in front of the eyepieces with flashlight shining behind, then put my phone on the object plane with camera pointing upwards.
I did as you suggested and illuminated the eyepieces with a flashlight. I put a piece of mylar on the object plane and put my phone below in 'selfie mode' so I can see what it's taking a picture of. Apologies for the low res but you can clearly see the same shape on both sides. The left side is the usual blue tint (more pronounced) but you can see a subtle reddish tint on the right side that is also the same shape.
Would there be any reason for making one side blue and the other red? Also, perhaps fungus in the binocular tube is responsible for the light making that shape?
I'm new at this, I really appreciate your guidance.
EDIT: I added a second photo where I removed the objective turret, put a piece of paper in front of the eyepieces with flashlight shining behind, then put my phone on the object plane with camera pointing upwards.
Re: Reichert Polyvar Microscope
I was able to find a disassembly manual written in Italian. I've auto-translated most of the section relating to the Binocular Tube and found an interesting section.
"Fig. 1126b (left) - looking at the right side of the left eyepiece you see a dark bezel, resulting from the opacification of the semi-reflective layer visible above. The photo was taken with the magnification cam in position 0,8 o . In other positions, naturally, the field of view is reduced and the dark bezel tends to disappear beyond the right margin of the field."
Perhaps this 'opacification of the semi-reflective layer' is what is causing this problem?
"Fig. 1126b (left) - looking at the right side of the left eyepiece you see a dark bezel, resulting from the opacification of the semi-reflective layer visible above. The photo was taken with the magnification cam in position 0,8 o . In other positions, naturally, the field of view is reduced and the dark bezel tends to disappear beyond the right margin of the field."
Perhaps this 'opacification of the semi-reflective layer' is what is causing this problem?
Re: Reichert Polyvar Microscope
... I was able to detach the binocular tube from the main body and I found that the last prism in the series has a spot on it. Any idea what this spot might be caused by? Should I attempt to clean it off? And if so, would Ammonia-free 'Sparkle' with Kimwipes be safe to use on the prism? I feel like I'm really close to having this resolved. Any help is much appreciated!
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Re: Reichert Polyvar Microscope
If this really is dirt on the surface this will be easy to cure. To avoid scratching the surface by rubbing dirt particles over it the cleaning should be done with very little pressure. A good first try is breathing on it an wiping with a piece of clean tissue. Very good and comparatively harmless is med. petroleum ether. It doesn't attack many materials and evaporates without a trace. It removes oil and grease, what water doesn't manage.
Bob
Bob
Re: Reichert Polyvar Microscope
I haven't fully investigated this yet but it seems this part is two prisms glued together with a semi-reflective layer. Perhaps the semi-reflective layer is coming undone and that is why I'm getting this spot.
I wonder if temperature has anything to do with it. This microscope was kept in a cold garage for a few months and I brought it indoors to its new home recently. Could the temperature change have caused the prism to separate?
I wonder if temperature has anything to do with it. This microscope was kept in a cold garage for a few months and I brought it indoors to its new home recently. Could the temperature change have caused the prism to separate?
Re: Reichert Polyvar Microscope
Yes. An acquaintance of me is caring for lots of microscopes professionally for decades now. He has developed the opinion that delamination is promoted by temperature changes, especially towards lower temperatures. Since this is quite plausible I tend to stick to this theory. Of cause there is lots of microscope optics that has seen severe temperature changes without signs of delamination, but some components are much more susceptible that others.
Bob
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Re: Reichert Polyvar Microscope
Since various cements have been used in compound optics, de-lamination has different characteristics, depending on the type of cement used. In some cases, the factory providing the cement, made a dud batch, which did not stand the test of time or the formula turned out to have a photo reaction over time. Most problems however , are caused by the drying out of volatile compounds in the cement. While there is no doubt that contraction of the glass elements and cement in complex optical systems can accelerate de-lamination, the de-lamination is usually caused by one of several other things. A) evaporation of volatile compounds in the cement or B) Improper curing of the cement or C) a photo reaction in the cement. D) mechanical shock or torsion. or a combination of .
A lot of de-lamination in optics, takes a circular or concentric form, showing first at the exterior of the optic and working inwards over time. Often, one can see that the cement has essentially dried out, from the outside of the cement layer in. Sometimes, crystals are formed due to the drying. This is very common with balsam . Sometimes, drying can be enhanced due to low temperature contraction and therefore increased exposure of the cement layer to air, or can be just enough that a severe temperature drop finishes the process, or can allow condensation to enter during the period of warm up. In large optics, condensation can get trapped.
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A lot of de-lamination in optics, takes a circular or concentric form, showing first at the exterior of the optic and working inwards over time. Often, one can see that the cement has essentially dried out, from the outside of the cement layer in. Sometimes, crystals are formed due to the drying. This is very common with balsam . Sometimes, drying can be enhanced due to low temperature contraction and therefore increased exposure of the cement layer to air, or can be just enough that a severe temperature drop finishes the process, or can allow condensation to enter during the period of warm up. In large optics, condensation can get trapped.
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Re: Reichert Polyvar Microscope
I wonder if it is indeed delamination because the separation seems to be coming from the inside and not from the edges. Could there be any other reason for this? I don't want to investigate too much out of fear I may make things worse, but I welcome other thoughts/ideas before moving forward.
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Re: Reichert Polyvar Microscope
I am pretty sure you have a cement failure in the beam splitting prism: probably what you are calling a semi-reflective layer. In many heads, there is just this one cemented surface, causing the same visual anomaly on both sides but with one appearing quite apparent and the other appearing as a kind of ghost image of it.
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Re: Reichert Polyvar Microscope
Yeah, that's got to be a delam. That's a real bummer.
Re: Reichert Polyvar Microscope
Ok, so now let's talk about whether I can fix it. I think it's doable I just wonder if it's worth the effort. Does anyone have any experience with UV Optical Adhesive or Canada Balsam? From my research, it seems I could separate the two pieces using warm water or soaking it in acetone for many days. After that, a simple clean and glueing with the adhesive, I think I'd be good to go. But would love to hear what anyone with experience with this thinks.apochronaut wrote: ↑Mon Jan 13, 2020 7:14 pmI am pretty sure you have a cement failure in the beam splitting prism: probably what you are calling a semi-reflective layer. In many heads, there is just this one cemented surface, causing the same visual anomaly on both sides but with one appearing quite apparent and the other appearing as a kind of ghost image of it.
Re: Reichert Polyvar Microscope
UV-curable adhesives from Norland (USA) are fairly easy to apply. Such as Norland 61 that has an RI of ~1.55. They cover a range of refractive indice, to match the RIs of various glasses. They are not inexpensive though.MWK wrote: ↑Tue Jan 14, 2020 12:44 amOk, so now let's talk about whether I can fix it. I think it's doable I just wonder if it's worth the effort. Does anyone have any experience with UV Optical Adhesive or Canada Balsam? From my research, it seems I could separate the two pieces using warm water or soaking it in acetone for many days. After that, a simple clean and glueing with the adhesive, I think I'd be good to go. But would love to hear what anyone with experience with this thinks.
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Re: Reichert Polyvar Microscope
Realigning the prism after removing and repairing it could be something of a challenge as well.
Re: Reichert Polyvar Microscope
I was able to find a pretty dusty Polyvar at a used store and picked it up for a fair price. It had a working and clean Condenser (something I was missing on my unit) but unfortunately the binocular tube prisms are even worse on this one. My goal is to experiment with fixing this prism first so that if I'm successful, I can apply the same technique to my current Polyvar. Also, I was able to get a camera adapter with this second unit that I hope to modify to fit my DSLR onto it. If I bypass the binocular tube, I'll be avoiding the delamination problem altogether, so that's good!
Eitherway, anyone else looking for Polyvar parts? I'm willing to let them go for fair price to to cover some of the costs of my purchase. Let me know if you need anything and I can see if I have it and if it's in good condition.
I think I'm going to put a hold on this project at the moment since fixing the prism will definitely be more difficult than I had previously imagined.
Thank you everyone for all the help in identifying and explaining this problem to me!
Eitherway, anyone else looking for Polyvar parts? I'm willing to let them go for fair price to to cover some of the costs of my purchase. Let me know if you need anything and I can see if I have it and if it's in good condition.
I think I'm going to put a hold on this project at the moment since fixing the prism will definitely be more difficult than I had previously imagined.
Thank you everyone for all the help in identifying and explaining this problem to me!
Re: Reichert Polyvar Microscope
I've seen Polyvar's with both a separate head and one that's inclinable and built into the upper frame. A picture of your scope might help - there were several versions.
If it is the former, I suspect you could get a Leica/Reichert head from a Microstar or Diastar and find it optically compatible, though likely a slightly smaller field. The binocular versions are pretty cheap.
If it is the former, I suspect you could get a Leica/Reichert head from a Microstar or Diastar and find it optically compatible, though likely a slightly smaller field. The binocular versions are pretty cheap.
Re: Reichert Polyvar Microscope
This is the one I have two of now. One working really well minus the binocular tube prism delam and the other for parts only.
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Last edited by MWK on Wed Jan 15, 2020 6:25 pm, edited 1 time in total.
Re: Reichert Polyvar Microscope
MWK - the image isn't displaying; at least for me.
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Re: Reichert Polyvar Microscope
By the way... Does anyone know what is the actual composition of the various cements/glues the microscope manufacturers have used? There must be different types of cements as e.g. Zeiss frequently tends to delaminate and Leitz do not. Would be interesting to know.
Re: Reichert Polyvar Microscope
I know for sure that the Polyvar isn't using Canada Balsam. I have it sitting in a hot water bath right now and the prisms aren't budging. I actually have an extra more damaged set of the binocular tube so I'm testing with that first.
I read somewhere that Methylene Chloride might be worth trying to unglue the prisms. This might be my next attempt.
Currently, the hot water bath is helping me detach the prism from the actual binocular housing. That is working. You would want to detach the prism from this housing before dunking it into any strong agent like Methylene Chloride since you don't want to damage the paint on the housing.
I read somewhere that Methylene Chloride might be worth trying to unglue the prisms. This might be my next attempt.
Currently, the hot water bath is helping me detach the prism from the actual binocular housing. That is working. You would want to detach the prism from this housing before dunking it into any strong agent like Methylene Chloride since you don't want to damage the paint on the housing.
Re: Reichert Polyvar Microscope
Maybe I spoke too soon.
The prism did come apart (which is great!) and after some cleaning, both surfaces look worthy for a gluing attempt with Canada Balsam. If I can successfully glue this prism back together with good results, I may be confident enough to attempt to fix the prism on the microscope I'm actually using at the moment.
But, as for the original adhesive, it doesn't seem like it was Canada Balsam because it didn't really dissolve. The adhesive is still intact and simply released once the temperature was hot enough (boiling water). Any idea what adhesive might be in use here?
The prism did come apart (which is great!) and after some cleaning, both surfaces look worthy for a gluing attempt with Canada Balsam. If I can successfully glue this prism back together with good results, I may be confident enough to attempt to fix the prism on the microscope I'm actually using at the moment.
But, as for the original adhesive, it doesn't seem like it was Canada Balsam because it didn't really dissolve. The adhesive is still intact and simply released once the temperature was hot enough (boiling water). Any idea what adhesive might be in use here?
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Re: Reichert Polyvar Microscope
Nice looking scope. There's a slight chance I may have a set of prisms - be a week or so before I can check.
Re: Reichert Polyvar Microscope
Thanks! Keep me posted!
I checked all options on Ebay and all the prisms are delaminated. Perhaps someone has some new old stock somewhere. That would be amazing, but otherwise I plan on trying to fix myself. Hopefully this post will help others in the future trying to do the same.
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Re: Reichert Polyvar Microscope
Have you tried ethanol on those cement bits? The yellowing in the thicker portions exposed to the air is a suspicious symptom that reminds me of balsam.
Re: Reichert Polyvar Microscope
I will try Ethanol.
The cement bits are pretty hard and crack when I bend them. The other bits (also yellow, look like tear drops) are very flexible, almost like silicone. The prism was attached to the housing with these little pieces.
EDIT: I tried Ethanol and Acetone and the bits don't dissolve in it.
The cement bits are pretty hard and crack when I bend them. The other bits (also yellow, look like tear drops) are very flexible, almost like silicone. The prism was attached to the housing with these little pieces.
EDIT: I tried Ethanol and Acetone and the bits don't dissolve in it.
Re: Reichert Polyvar Microscope
What would constitute a severe temperature drop?
Zeiss Photomicroscope III BF/DF/Pol/Ph/DIC/FL/Jamin-Lebedeff
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