Orthoplan Help Needed

[JGardner]

My new Orthplan arrived today and I have several questions regarding its configuration and operation.

The microscope was very well packed and seemed to survive the trip well. One thing that was amiss, however, was the elliptical mirror at the base of the stand that diverts the light from the lamp house up to the condenser. It was detached and flopping around loose. I managed to delicately push it back to where it belongs, but it's just sitting there and not really attached. How is this mirror retained? Is it glued to a mount, held in place by a metal clip? Some other mechanism? It'd like to secure it so it won't move around. It's also very dirty. I assume it's a first surface mirror and requires very careful cleaning. What is the procedure for cleaning it?

Another issue, perhaps more serious, is the field iris doesn't move. The wheel that controls its size appears to be completely frozen and doesn't move at all. When the microscope arrived the iris was completely open and I can't budge it. How should I approach this issue? Use more force on its control wheel to try and break it free? There doesn't see to be access to the iris mechanism from underneath the stand--that appears to be a single unit held in place by screws. Should I try removing the unit to get better access to the iris mechanism? Will a penetrating agent help, or do more harm than good?

Another issue is the centering screws on the condenser. When turning them to try to center the condenser they don't seem to do much, if anything. I don't see how two screws 45 degrees apart can do more than move the condenser in one direction by tightening them. Loosening them doesn't seem to do anything. Are there springs in the condenser that are supposed to keep the condenser in contact with the screws when the centering screws are loosened?

The focusing mechanism seems to work fine. The coarse adjustment is a little tight, but it moves very smoothly. The fine adjustment moves with little effort and is very smooth. Is that normal for this scope?

One of the eyepieces is marked GW 10x M and the other is GW 10x MF (the F is red). What's the difference? What does the "F" signify? One of the eyepieces has a reticle that assume is used to show the field of view of a camera. I don't want this--is there any way to remove it short of buying a new eyepiece?

There was a mystery part loose in the box. Anyone know what this is and where it goes?



I appreciate any and all help!

[Hobbyst46]

Hello JGardner

Some general microscope tips based on my experience with other, non-Leitz microscopes:

Mirror: if it is a first surface mirror, it may be VERY sensitive. If the dirt is obvious and annoying, I would try to clean it with clean compressed air (NOT machine shop compressed air, that contains oil droplets). Or a camera lens air blower + brush (soft brush. Then if still necessary, breath on the mirror, then sweep once and very lightly with a Q-tip/lens tissue. Rubbing with acetone or other solvent will probably cause damage.

Coarse focusing mechanism: slight tightness is OK, I would not tamper with it as long as it functions.

Unidentified item in the photo: probably a filter holder. For interchangeable round filters.

[Charles]

Pictures of the affected areas help a lot. Take some pictures of the mirror and holder and the condenser holder.

The picture of the part does appear to be a filter holder. Just guessing but probably attaches somewhere in the light path...maybe to the rear where the light lamp goes or over the light port?

[mrsonchus]

Hi, yes, that's a (lollipop) filter-holder for the 600 series condensers. It fits onto the bottom of the condenser in the right position to allow full movement of the iris lever. These are very useful - I have one fitted to my Big-O. They fetch about £60-£70 on e-bay!

I always slip a frosted filter into mine when using the x2.5 objective to give a nice even spread of light. Oh yes, does your condenser have a supplemental lens in it's bottom - marked as a 'K4' - the extra-wide (at the time at least) field of the Orthoplan needs one to be able to fill the lower-powered objectives with light and to make it possible to bring the field-iris leaves into focus for Kohler illumination.

A good item you have there - I'd keep that filter holder if I were you - It'll come in very handy....

John B.

p.s. Here are a couple of images of mine....

ws_603 condenser filter holder (2).jpg (53.67 KiB) Viewed 4375 times

Fits like this, on bottom of condenser,

ws_603 condenser filter holder (5).jpg (37.87 KiB) Viewed 4375 times

Here's a (partially inserted) K4 lens needed for the Orthoplan's condenser,
it pushes in to be flush with bottom of condenser...

ws_condenser K4 arrival and fitting (13).jpg (40.2 KiB) Viewed 4375 times

Hope this helps your setup.

John B.

[JGardner]

I always slip a frosted filter into mine when using the x2.5 objective to give a nice even spread of light. Oh yes, does your condenser have a supplemental lens in it's bottom - marked as a 'K4' - the extra-wide (at the time at least) field of the Orthoplan needs one to be able to fill the lower-powered objectives with light and to make it possible to bring the field-iris leaves into focus for Kohler illumination
John B.

Thanks John. I’ll try to attach that unit to my condenser when I get home. I’m 99.9% certain that my condenser does not have the K4 supplemental lens. I’ll post some pictures of the parts when I get home. Right now the scope only has 10x and 32x objectives and I haven’t noticed any light falloff at the edges of the field of view. As for bringing the field iris leaves into focus, that’s not an issue right now as the field iris is frozen solid in its fully open position—any idea how to remedy that?

Jerry

[mrsonchus]

Hi Jerry, hmm, when it comes to fixing the parts etc I'm really not the man for the job....
Having said that, this forum has some exceptionally talented and experienced restorers of beautiful 'scopes on-board. It's only a matter of time before one of them spots this thread I'm certain...

Perhaps start a thread with the title "help needed with stuck field iris" - to catch their eye...

Good luck, but you've certainly come to the right place for very high-level expertise and advice my friend.

John B.

[JGardner]

Here are the photos of the condenser and the filter holder:







I'm still at a loss as to how to attach these two parts together. What's the purpose of the thumbscrew on the filter holder? It doesn't see to do anything because when I loosen it completely it doesn't seem to free anything. Perhaps that's because two parts have seized?

The eBay photos of this microscope show the filter holder inserted in the opening at the base of the stand where the light from the lamp house it directed upwards to the condenser. It's a perfect fit--perhaps this particular part is meant to go here?



There is definitely no K4 lens in this condenser. Is that lens a standard part of the condenser or an optional add-on?

Is the condenser centering mechanism spring-loaded? It would appear that the two centering thumbscrews only have an effect when tightening them. Loosening them does nothing, so I suspect that perhaps a set of springs that are supposed to keep the screw bearing surfaces in contact with the screws when they are loosened are somehow not functioning correctly. This is just a guess, however.

[mrsonchus]

Hmm, looks like the filter-holder was attached to the glass (and it's frame) that covers the light-port above the mirror. When the filter holder was removed it was pulled out complete with the glass! The glass should have remained over the light port (i.e. above the mirror) but because the turn-screw was not undone and the filter holder taken off of it, the whole thing, glass and all has been pulled out!

See my Orthoplan's glass,

ws_orthoplan-delivered-(8).jpg (31.92 KiB) Viewed 4352 times

Your images,

ws_IMG_0891.jpg (42.19 KiB) Viewed 4352 times

ws_IMG_0892.jpg (42.99 KiB) Viewed 4352 times

ws_IMG_0893.jpg (49.46 KiB) Viewed 4352 times

Look to be a possibility - first job is to separate the filter-holder from the light-port cover glass and frame I think....

John B.

Oh yes, your condenser doesn't appear to have a K4 fitted but you won't be able to test focusing the filed-iris leaves and the slide specimen simultaneously as for Kohler until you have the field-iris working - are you sure you're trying to turn the correct wheel for the field iris and not the collecting lens turn or the cover glass clamp by mistake?

Just a thought.

John B.

[JGardner]

Look to be a possibility - first job is to separate the filter-holder from the light-port cover glass and frame I think....

Makes sense. I’ll try to separate the two parts, perhaps after heating the outer part up to expand it a bit.

are you sure you're trying to turn the correct wheel for the field iris

Yes. I’m trying to turn the large vertical wheel labeled “field-iris wheel” in your annotated photo.

[JGardner]

Some success! I used a hair dryer to heat the outer part of the filter holder and was able to separate the two pieces. Now it's obvious how the filter holder mounts on the bottom of the condenser and how the smaller part with the glass mounts in the light port in the base.

All of the optics of this microscope are exceptionally dirty. Time to do a thorough cleaning. The biggest remaining obstacle is getting the field iris freed up.

[75RR]

All of the optics of this microscope are exceptionally dirty. Time to do a thorough cleaning.

A very useful pamphlet on cleaning the microscope

http://microscopy.duke.edu/sites/micros ... scsope.pdf