Polyvar condenser problem.I need advise.

A forum to ask questions, post setups, and generally discuss anything having to do with photomacrography and photomicroscopy.

Moderators: ChrisR, Chris S., Pau, rjlittlefield

sebba28
Posts: 296
Joined: Thu Dec 29, 2011 11:13 pm
Location: Poland,Ireland

Polyvar condenser problem.I need advise.

Post by sebba28 »

Hi

I have a biological microscope Reichert Polyvar with a universal condenser BF, DF, PH, DIC. The problem is that I can't adjust the lighting according to Kohler. I proceed in this way: I leave the condenser down, close the field iris diaphragm, then raise the condenser up and when I see that there is a little lack to Kohler I can not raise the condenser higher because it is already in the highest position.I read the and followed the manual instructionsher and got stuck.
What may be the problem?Any advice?

Online
enricosavazzi
Posts: 1276
Joined: Sat Nov 21, 2009 2:41 pm
Location: Borgholm, Sweden
Contact:

Re: Polyvar condenser problem.I need advise.

Post by enricosavazzi »

sebba28 wrote:Hi

I have a biological microscope Reichert Polyvar with a universal condenser BF, DF, PH, DIC. The problem is that I can't adjust the lighting according to Kohler. I proceed in this way: I leave the condenser down, close the field iris diaphragm, then raise the condenser up and when I see that there is a little lack to Kohler I can not raise the condenser higher because it is already in the highest position.I read the and followed the manual instructionsher and got stuck.
What may be the problem?Any advice?
Only a guess, but are you using the correct objectives for your microscope? For example, some Zeiss Jena and Lomo objectives have barrels too short for the stage of Zeiss Universal and Standard microscopes to allow focusing. Something similar might happen with the condenser rack if the objective barrels are too short for the microscope stand.
--ES

Pau
Site Admin
Posts: 5132
Joined: Wed Jan 20, 2010 8:57 am
Location: Valencia, Spain

Post by Pau »

Assuming that the objectives can focus on the slide at the stage without problems,

A 10X objective is usually recommended to adjust the microscope.

- Check if the condenser holder mount is easily removable and if it is placed at its right position. I don't know well the Polyvar but modular microscopes often have the stage and condenser holder removable and and their position on the focusing rack could be raised or lowered. It seems that it could be the case after seeing the images you posted

- What's the condenser top lens NA? (low NA condensers often do not allow for Kölher, but likely this is not the case)
Pau

Pau
Site Admin
Posts: 5132
Joined: Wed Jan 20, 2010 8:57 am
Location: Valencia, Spain

Re: Polyvar condenser problem.I need advise.

Post by Pau »

enricosavazzi wrote:...For example, some Zeiss Jena and Lomo objectives have barrels too short for the stage of Zeiss Universal and Standard microscopes to allow focusing. Something similar might happen with the condenser rack if the objective barrels are too short for the microscope stand.
This is true with small Standards stands but with the WL I can raise both the stage holder and condenser holder in the focus block to work with short barrel objectives. Sharing these components with the WL, I think that Universal and Photomic would be able to do the same
Pau

Online
enricosavazzi
Posts: 1276
Joined: Sat Nov 21, 2009 2:41 pm
Location: Borgholm, Sweden
Contact:

Re: Polyvar condenser problem.I need advise.

Post by enricosavazzi »

Pau wrote:[...]This is true with small Standards stands but with the WL I can raise both the stage holder and condenser holder in the focus block to work with short barrel objectives. Sharing these components with the WL, I think that Universal and Photomic would be able to do the same
I got rid of my Photomicroscope a couple of years ago and my memory might be faulty.

While I still have a Standard and had this very same problem (once more) recently, the problem I had with my Photomic might have been instead that a short objective mounted among objectives of the correct length could not focus because the two adjacent objectives on the objective turret prevented focusing, rather than the focus rack itself. I do remember that there was "some kind of" problem preventing me to focus with Lomo and Zeiss Jena short objectives also on the Photomic.
--ES

sebba28
Posts: 296
Joined: Thu Dec 29, 2011 11:13 pm
Location: Poland,Ireland

Post by sebba28 »

Thank you Pau and Enrico.


I'm doing everything right,I use proper objectives,but still don't know why the condenser don't whant to rise to the top.My temporary solution was to place a 1.5mm washer under the front lenses of the condenser to make them higher and now it works.

Post Reply Previous topicNext topic