Hi Everyone,
I have a Leitz Laborlux 12 Pol and I just purchased a Leitz 2.5x objective for it. However, I cannot get the slide in focus. I have tried adjusting the stage up and down to its full range but still no luck. Any suggestions? Am I missing something obvious?
Cheers,
Dan
Leitz 2.5x objective won't focus
Leitz 2.5x objective won't focus
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Re: Leitz 2.5x objective won't focus
Dan, I'd look to your intermediate pieces, for reflected light, what looks like a polarizer intermediate, and your head.
One type will have a correction lens inside, increasing the magnification some, but allowing a 160 tube objective (like your 2.5x) to function with a normal 160 tube. You'll want that.
Another type will be essentially air space (with the split beam mirror to reflect light and/or a polarizer and allow viewing) and is intended for infinity objectives.
Could also (rarely) be that someone pulled an element out of your 2.5x -- might look to see if telltale marks show it having been worked on. Your condenser may or may not be able to cover the entire field of view of the 2.5x as well.
One test for you is to pull off the epi and polarizing intermediate pieces and see if you can get focus. If that fails, check the head model to make sure it's meant for finite tube objectives.
One type will have a correction lens inside, increasing the magnification some, but allowing a 160 tube objective (like your 2.5x) to function with a normal 160 tube. You'll want that.
Another type will be essentially air space (with the split beam mirror to reflect light and/or a polarizer and allow viewing) and is intended for infinity objectives.
Could also (rarely) be that someone pulled an element out of your 2.5x -- might look to see if telltale marks show it having been worked on. Your condenser may or may not be able to cover the entire field of view of the 2.5x as well.
One test for you is to pull off the epi and polarizing intermediate pieces and see if you can get focus. If that fails, check the head model to make sure it's meant for finite tube objectives.
Re: Leitz 2.5x objective won't focus
Thanks Pete!
Looks like the intermediate piece has an infinity symbol/1x on it. The scope is set up for polarized transmitted and reflected light. I only need to use it for polarized transmitted. If I remove the intermediate piece, I can get the 2.5x to focus. However, this means I cannot look at the slide in XPL. Am I going to need to buy a new intermediate piece in order to use the 2.5x with XPL?
Dan
Looks like the intermediate piece has an infinity symbol/1x on it. The scope is set up for polarized transmitted and reflected light. I only need to use it for polarized transmitted. If I remove the intermediate piece, I can get the 2.5x to focus. However, this means I cannot look at the slide in XPL. Am I going to need to buy a new intermediate piece in order to use the 2.5x with XPL?
Dan
Re: Leitz 2.5x objective won't focus
Dan,
On edit -- you're going to have to come up with another way of getting a polarizer above the objectives. Am I seeing a polarizer (wave plate? filter? prism?) sticking out from the right side of the nosepiece?? And then the one clearly visible in the intermediate head? If you don't have a polarizer slot as part of the stand, you might well be able to fit a bit of film or even a photographic type polarizer between the stand and the head.
You'll still need a polarizer above the field lens -- perhaps it's in your condenser?
You should check your higher power objective (longer barrel than the 2.5x). Can I assume this is infinity marked? At some point you're going to have to decide whether you want a set of 160 tube or infinity objectives -- or suffer continually swapping parts.
On edit -- you're going to have to come up with another way of getting a polarizer above the objectives. Am I seeing a polarizer (wave plate? filter? prism?) sticking out from the right side of the nosepiece?? And then the one clearly visible in the intermediate head? If you don't have a polarizer slot as part of the stand, you might well be able to fit a bit of film or even a photographic type polarizer between the stand and the head.
You'll still need a polarizer above the field lens -- perhaps it's in your condenser?
You should check your higher power objective (longer barrel than the 2.5x). Can I assume this is infinity marked? At some point you're going to have to decide whether you want a set of 160 tube or infinity objectives -- or suffer continually swapping parts.
Re: Leitz 2.5x objective won't focus
Pete,
All the objectives are 160. However the 4x, 10x 20x, and 63x all work fine with the infinite tube. Should I just try and find a different intermediate tube? There is a polarizer in the condenser, but without another one I can't look at the thin sections in cross polarized light which is pretty essential to the work I'm doing.
OR....Is there a different 2.5x objective I could buy that might work with the current intermediate tube?
All the objectives are 160. However the 4x, 10x 20x, and 63x all work fine with the infinite tube. Should I just try and find a different intermediate tube? There is a polarizer in the condenser, but without another one I can't look at the thin sections in cross polarized light which is pretty essential to the work I'm doing.
OR....Is there a different 2.5x objective I could buy that might work with the current intermediate tube?
Re: Leitz 2.5x objective won't focus
Dan, What I think is happening is that your finite objectives are getting magnified by the extra tube distance - 40 mm or so -- with that intermediate illuminator in place. Could also be there's some sort of compensating lens in it -- not familiar enough with Leitz to know what setup you might have. If you've effectively increased the tube distance (say, to 200mm), while the images might look OK to the eye, they're not likely to be parfocal and they ARE likely to show more obvious optical defects once you start trying to take pictures. You've just run out of focusing distance with the 2.5x it seems.
Are all your objectives roughly parfocal once you remove the intermediate piece?
Given that -- once you remove the intermediate illuminator, there should be enough space between the head and the stand to insert a thin bit of linear polarizing film. Try that. If it works (and it should if you have a standard finite type head), I believe there is a glass polarizer with a metal surround meant to fit that space for Leitz Laborlux. That would then be your best/cheapest option for a permanent solution -- finding one of those on Ebay. You might also have just enough room to insert a thin glass polarizer of an appropriately small diameter from camera sources. Those are generally very affordable and available in a wide variety of diameters.
Are all your objectives roughly parfocal once you remove the intermediate piece?
Given that -- once you remove the intermediate illuminator, there should be enough space between the head and the stand to insert a thin bit of linear polarizing film. Try that. If it works (and it should if you have a standard finite type head), I believe there is a glass polarizer with a metal surround meant to fit that space for Leitz Laborlux. That would then be your best/cheapest option for a permanent solution -- finding one of those on Ebay. You might also have just enough room to insert a thin glass polarizer of an appropriately small diameter from camera sources. Those are generally very affordable and available in a wide variety of diameters.
Re: Leitz 2.5x objective won't focus
You have probably already sourced this from the internet as I did, but just in case you have not done it yet:
http://earth2geologists.net/Microscopes ... ochure.pdf
http://earth2geologists.net/Microscopes ... ochure.pdf
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)
Olympus E-P2 (Micro Four Thirds Camera)
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Re: Leitz 2.5x objective won't focus
If the objective can be brought to focus in an infinity system, it is likely that it will be the most of all of them affected by the altered tube length.
There may be an intermediate image difference between the infinity tube system and the 150mm that the Leitz 160mm system was built to. Small differences affect the lower magnifications , more than higher magnifications. You might already notice that the 10X, although performing well, might be slightly below the performance of the higher power objectives, which are relatively unaffected due to their high magnification.
This difference will also affect the W.D., perhaps why it is unable to focus.
There may be an intermediate image difference between the infinity tube system and the 150mm that the Leitz 160mm system was built to. Small differences affect the lower magnifications , more than higher magnifications. You might already notice that the 10X, although performing well, might be slightly below the performance of the higher power objectives, which are relatively unaffected due to their high magnification.
This difference will also affect the W.D., perhaps why it is unable to focus.