LOMO 2.5 Objective Focusing

[75RR]

This looks like it might be the missing condenser: https://www.ebay.com/itm/LOMO-condenser ... SwjLxehvOw

On the other hand the article does mention Phase so perhaps it is this one: https://www.ebay.com/itm/LOMO-Phase-Pol ... Swk1JWcwFa

[riorio44]

Clutching at straws here but I wonder if the intermediate image is at a different height when using the 2.5x.

If this was the case, what would need adjusted?

I suspect maybe there is a missing element from the rear of the objective.

back of 2.5 obj.jpg (127.33 KiB) Viewed 5537 times

It seems to me like something is missing, but I don't know what it would look like.

Regarding the condensers, the one with the phase contrast is the one I currently have mounted. The other one has a 1.25NA lens on it and it resembles the other condenser. I have tried the 1.25NA also, with no luck.

EDIT:
I just came across this image. I'm not sure what the piece is next to the objective, but perhaps that is what I am missing?

[75RR]

Regarding the condensers, the one with the phase contrast is the one I currently have mounted. The other one has a 1.25NA lens on it and it resembles the other condenser. I have tried the 1.25NA also, with no luck.

Did not realize that you had both condensers.

I'm not sure what the piece is next to the objective, but perhaps that is what I am missing?

It is to centre the objective on a polarizing microscope. See image:

[75RR]

It might be a good idea to post a photo of your complete microscope instead of just bits and pieces.

Do you have a normal nosepiece or something like in the image above?

[MichaelG.]

I hadn't tried that before. Unfortunately it still isn't focusing. I had tried to remove the 0.85 lens of the condenser with no luck. I placed the neutral density filter over the light output and it allowed me to see a blurred image, yet it still would not focus.

I have a feeling it's something simple that I'm missing. I'm just not exactly sure what I'm doing wrong.

Quoted [with my emboldening] for ease of reference ^^^

If that 0.85 lens is stuck then you need to find a way to release it.
... But let’s get the 2.5x objective sorted first.

MichaelG.

[riorio44]

My wording wasn't the best there. I am able to remove the 0.85NA lens. There was no luck with focusing. Sorry for the confusion!

I attempted to photograph the 'focused' image with the eyepiece removed on the 2.5x objective which shows most of the setup of the microscope:

scope.jpg (80.87 KiB) Viewed 5528 times

It is a normal nosepiece. I will take better photos of my setup when I get home.

In the meantime, this is the closest setup to what I have working:

[75RR]

I am able to remove the 0.85NA lens. There was no luck with focusing.

A photo of the condenser with the 0.85 top removed to confirm the 0.30 lens is in position would be useful.

Try to include side shot of 2.5x objective in position - 9mm above specimen + lots of photos of your very interesting microscope as well.

[MichaelG.]

My wording wasn't the best there. I am able to remove the 0.85NA lens. There was no luck with focusing. Sorry for the confusion!

.

Thanks for the clarification.

MichaelG.

[MichaelG.]

I suspect maybe there is a missing element from the rear of the objective.

That would certainly explain a lot !!!

Could you get a more detailed photo of the back end of your 2.5x please
... something that we can compare directly with the other image you found.

MichaelG.

.
Edit: I think this is from the same ebay listing as the one you posted :

LOMO 2.5x 0.05NA

C13329D5-6A3D-4BD2-9016-204188BAAF96.jpeg (180.66 KiB) Viewed 5503 times

[75RR]

Could you get a more detailed photo of the back end of your 2.5x please
... something that we can compare directly with the other image you found.

Agree that it is not entirely clear if riorio44's 2,5x objective is missing the rear lens or not. A better photo would help.
.

[riorio44]

Here are some views of the back of the objective

2.5 angle back.jpg (118.87 KiB) Viewed 5476 times

back 2.5 topdn.jpg (97.33 KiB) Viewed 5476 times

2.5 back.jpg (85.16 KiB) Viewed 5476 times

And the condenser, both with the 0.85NA and without (for 0.30NA)

condenser .85.jpg (85.05 KiB) Viewed 5476 times

condenser .3.jpg (84.66 KiB) Viewed 5476 times

[riorio44]

And the POLAM!!!

scope.jpg (76.51 KiB) Viewed 5475 times

[MichaelG.]

Thanks for the pictures

The objective looks complete, I think

So we need another line of investigation

MichaelG.

[riorio44]

I'm starting to heavily lean toward putting the 2.5 back in the box!

[riorio44]

SOLVED!!!!

As I was taking the 2.5x objective to the retirement home, I decided to disassemble the entire microscope.

Upon reassembly, I noticed threads on the bottom of the intermediate tube. Then the light bulb went off. This random glass piece that was in the box with the objectives that I couldn't for the life of me figure out what it was for, finally had a home.

the piece.jpg (44.42 KiB) Viewed 5465 times

I inserted it into the bottom of the intermediate tube and set the rest of the microscope up and eureka it works!!!!

Thank you all who took the time to help me with this. I wouldn't have gone as far as I would with troubleshooting had you guys not shown interest in it. I was about to give up on it and toss the 2.5x objective to the side forever.

Thanks again!

[BramHuntingNematodes]

Clutching at straws here but I wonder if the intermediate image is at a different height when using the 2.5x.

If this was the case, what would need adjusted?

The eyepiece, friend, the eyepiece. You can lengthen the "tube" by pulling back on the eyepiece. See if you can somehow get the image in focus and note how far retracted it is!

[75RR]

There is something about miniature microscopes ... I suppose the word is cute!

I inserted it into the bottom of the intermediate tube and set the rest of the microscope up and eureka it works!!!!

:) :)

[MichaelG.]

Another source of information about the mighty POLAM
http://www.mikroskopfreunde-nordhessen. ... olam-L.pdf

MichaelG.

[riorio44]

Thanks for the file. I went ahead and had it translated to English.

Polam-L.de.en.pdf

(441.09 KiB) Downloaded 162 times

I had previously found a document in Russian.

lomo polam_compressed.pdf

(388.6 KiB) Downloaded 164 times

I was able to translate it into 'workable' English.

lomo polam eng_compressed (1).pdf

(412.76 KiB) Downloaded 145 times

Just in case any of you are interested or other LOMO owners need a reference.

[alandavison]

Very grateful for the info on the Polam 213. I have the 211, the photo is almost the spitting image. This helps me enormously.
I do not have either objectives or eyepieces. I do have other 'scopes with telaugic (& cross wires) eyepieces and /160 phase contrast objectives.
Hoping to find an instruction manual.