Leitz UV 16x microscope objective meets a Buttercup

[JMC]

Another unusual lens to share with you. This is a Leitz UV 16x / 0.25 microscope objective. Picture of the lens is below;

 

 

 

It have a RMS thread, and is for a 160mm tube length microscope. One very interesting thing about it is its UV transmission, which I've measured;

 

 

This is still transmitting very well down at 280nm so must be a quartz and/or calcium fluoride lens with no glass in it. Absolute transmission may well be a bit higher than this, as it's a struggle for me to measure it through such a small lens.

 

As a quick test of it, I set it up on my UV converted Nikon d810, as I did here (although I did put it on 6.5cm of extension tubes this time) - https://www.ultravio...dpost__p__35417

 

Below is an image of a Buttercup petal, looking at the region between where it appears yellow in the UV and where it appears black. This is single image (no focus stacking). This is the full frame of the image, just resized for sharing.

 

 

Magnification here is about 9x or 10x based on the extension.

 

Amazingly, it looks to have little if any focus shift from the UV to the visible. The parts of the petal in focus in the visible when I was looking through the viewfinder, were pretty much what was in focus in the UV. My d810 has one of the ACS UV filters in it and retains the Bayer filter so I'm mainly seeing UVA here. What I'm looking forward to is trying it for UVB imaging on one of my monochrome cameras.

 

It did have quite a lot of field curvature, but I was using it with too short an extension really given it was designed for a tube length of 160mm. I've tried it on my microscope, but not in UV, and it looks much better.

 

And........ I really need to build a decent photomacrography rig. This was with the camera on a tripod and a wooden floor. Every time I went near the camera or the subject to position it, the floor flexed and everything moved. Need to build something nice and solid.

 

I've not been able to find out anything about the lens. Leitz did apparently make a UV microscope, and found reference to a paper from the 60's talking about its use for looking at wood, but I don't have access to the paper so I'm not sure what lens they used. Leitz also made some Quartz glass objectives in 20x and 32x (and perhaps other magnifications too), but corrected for an infinity microscope. This isn't like those though.

[nfoto]

Nice find. As there is no secondary optics (eyepiece) to correct for field of curvature etc., no wonder this is present. With focus stacking this aberration ought to be brought to heel, through.

 

Ah yes wooden floors .... I'm using a modified Nikon Multiphot setup itself sitting on a very heavy table (over 150 kg) and this is about as stable as anything not cast into concrete can be.

[Andrea B.]

Looks very promising Jonathan.

[dabateman]

Jonathan a cheap alternative is marble. You can get a thick pastry board to place a subject on.

But the floor still offers some problems.

You might just need to move into the basement, like I have. I get more and more stuff setup down there.

 

That objective is very interesting. You can do UVB with your microscope. As long as the internal lenses don't absorb too much. My cheap one I got my daughter can handle UVA, she hasn't used it much so I have been using it more lately.

[JMC]

Yes, it was a fortunate find. Still trying to find out what it was originally from.

 

With regards to stability, the table the light source and subject are on is fine (made from 2" steel box section and with a thick wooden top). The issue is the floor that everything is on flexing, and having the camera on a tripod on the floor, so it can move relative to the subject.

 

I picked up a second broken Olympus microscope recently with the idea of salvaging the focus block to make a macro rig. However slight change of plans. I'm going to mount the camera vertically on the microscope, removing the eyepiece and objectives, essentially using the microscope as a solid camera mount. I can then move the subject on the stage. This will mount subject and camera on the same piece of equipment, and give me a focus mechanism for stacking. Illumination will be using my xenon or mercury xenon lamps, or flash if needed.

 

Unfortunately the optics on my transmission microscope wont be any good for UVB. Fine for UVA but not B. The build using the second, broken scope will be for reflection not transmission (although I do have some ideas how I could use it for transmission at some point).

[ulf]

There are some interesting dampening materials that can improve the situation further to insulate a platform, if applied correctly.

Sorbothane is one of them.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=sorbothane&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=sorbothane

[Dmitry]

Looking at another possible optics, I found this:

http://www.beckoptronic.com/products/reflecting-objectives/

[nfoto]

I guess if one has to ask for the price, that objective is out of one's reach ...

[Dmitry]

About 100-500 USD on ebay for used lens.

[JMC]

There are some interesting dampening materials that can improve the situation further to insulate a platform, if applied correctly.

Sorbothane is one of them.

https://www.ebay.com...odkw=sorbothane

Thanks Ulf, that'll be handy as I need new feet for the microscopes.

[JMC]

Small world. I've had my eye on one of the Beck objectives, albeit a much older one, for a while and pushed the button on it this morning. 52x, which is not ideal given the tiny working distance, but for 40GBP I thought I'd give it a go. No idea what the insides are like......

[dabateman]

Looking at another possible optics, I found this:

http://www.beckoptronic.com/products/reflecting-objectives/

 

Wow impressive! They have good NA, and great working distance. Even the standard looks to have excellent UV transmission to 200nm.

Something to keep an eye on.

Thanks Dmitry.

[dabateman]

Small world. I've had my eye on one the Beck objectives, albeit a much older one, for a while and pushed the button on it this morning. 52x, which is not ideal given the tiny working distance, but for 40GBP I thought I'd give it a go. No idea what the insides are like......

 

Jonathan, a 1.9mm working distance for a 52x is massive. Most of the Zeiss 40x and 63x I have used would be around 0.4mm.

 

A year ago I got a Nikon 40x with 2mm working distance, but thats a trade off with NA. A NA of 0.65 with that working distance, seems like crazy talk for a 52x.

[JMC]

Jonathan, a 1.9mm working distance for a 52x is massive. Most of the Zeiss 40x and 63x I have used would be around 0.4mm.

 

A year ago I got a Nikon 40x with 2mm working distance, but thats a trade off with NA. A NA of 0.65 with that working distance, seems like crazy talk for a 52x.

 

Yeah, perhaps I should have expanded a bit. I was thinking of using it with illumination from above (for reflected work), so it ain't much distance to get light in especially with it being such a big objective. But yes, for transmitted work it's a long working distance for a 52x objective :)

[dabateman]

I guess if one has to ask for the price, that objective is out of one's reach ...

 

A new 36x 5004-000 is $3395 USD.

 

Be careful not to get a Beck CBS, they are different. Beck CBS went out of business in the 1980s it looks like.

[JMC]

Small world. I've had my eye on one of the Beck objectives, albeit a much older one, for a while and pushed the button on it this morning. 52x, which is not ideal given the tiny working distance, but for 40GBP I thought I'd give it a go. No idea what the insides are like......

 

A word of caution for anyone thinking about getting one of these types of reflecting objectives. If you buy one second hand, make sure it comes with the special slide required for aligning the mirrors. They are not as simple to use as the refracting objectives, and require aligning if you change the tube length or cover slip thickness (or readjust its position on the scope). Definitely a lot more work.....

[KaJashey]

Another unusual lens to share with you. This is a Leitz UV 16x / 0.25 microscope objective...

 

...It did have quite a lot of field curvature, but I was using it with too short an extension really given it was designed for a tube length of 160mm.

 

I have a 3d design for an RMS microscope to Nikon F-Mount with 160mm of total extension. That's including the Nikon's own flange distance. Free to download here... https://www.thingive...m/thing:4259543