Leitz paperweight?

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

Moderators: rjlittlefield, ChrisR, Chris S., Pau

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Leitz paperweight?

Post by ChrisR »

Hello all, absolute beginner here.
Some of the images I've seen via this forum are heartstopping. We all have to die sometime, and it seems a wonderful way to go.

I thought if I bought a microscope objective, I could take close-ups. I suspect you can tell where this is going already. :oops:
I've done some more reading and found out that it wasn't a smart buy.
LWD , good.
For incident light, no coverglass required, good
It has an aperture, which I thought was good, until I read more about NAs.

After shoving it iinto some plumbing with a camera behind, I needed a stiff drink. The image got no better though.
It's not a Plan lens, the Chromatic aberrations are psychedelic, and field curvature is deep.
It's a Leitz, which means (I think) I need a Leitz compensating eyepiece (KPL?) to use it, really a projection type.
Even if I could find one at a beginner's price, it would give me far more magnification than I was after.

I've read a number of threads here which tell me what not to do, eg
http://www.photomacrography.net/forum/v ... 21&start=0
- too late!

Realising that the centre looked sharper than the edges, I tried focussing with a macro lens on the virtual image the correct distance from the objective. Horribler!

I'm not sure how to diplay this - is this Ok>?
http://img13.imageshack.us/img13/4296/uscopelens.jpg

Maybe a cheap/noname compensating eyepiece, but then what?
Please help, is there any hope?

rjlittlefield
Site Admin
Posts: 23564
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

ChrisR, welcome aboard!

That link you give is both fascinating and frightening. It describes objectives of a type that I've not seen before: specifically designed to view through a very thick quartz coverglass -- 1.8mm thick! If you do actually have one of these "heating stage" objectives, then the quartz coverglass has been included in the optical design. Leaving it out will introduce a significant amount of spherical aberration. This will degrade the image, but exactly how much depends on the magnification and numerical aperture of the lens.

Can you confirm, please, exactly what lens you have? What all is engraved or painted on it?

Also, what do you mean when you say "It has an aperture"? All lenses have apertures. With some of them it's adjustable, but I don't see that feature listed at the link you give.

Is there hope? Can't tell. You describe yourself as "absolute beginner", but I don't know what that means. Do you have experience with macro photography using conventional lenses at say 5X onto the sensor, or are you trying to jump from street photography to microscope objectives in one giant leap?

--Rik

Edited to add: ChrisR's link mentions a "Heating Stage 350". There is a "Leica 350 microscope heating stage" described at http://tinyurl.com/chfe79
(http://www.leica-microsystems.com/pdfs. ... glisch.pdf) .
I'm not sure it's the same beast, though.

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

Thaks for the quick reply Rik.
The lens is the one with the pretty rectangle in the link, 32/0.3 .
http://img24.imageshack.us/img24/4296/uscopelens.jpg
Its picture is on the left. The smaller knurled ring adjusts the iris, but not much. I was in my ignorance hoping to be able to alter the DOF, hey ho.

No more numbers on the lens.

I read that the lens could be used without the cover plate, and naive optimism got in the way of reason. I thought it would be OK. Dumb.

The vendor was kind enough to give a little more information, below, and I've been doing some bedtime reading:
http://www.science-info.net/docs/leitz/ ... ystems.pdf

Experience? Can't see any of that for sale on ebay. :cry:
I've just bought my first DSLR, have a bellows I bought in the 80's sometime, and a couple of enlarger lenses etc which I've got to fit, reversing rings etc.
I've done some slide copies which are rather nasty & contrasty despite my efforts to modify E6 developers, and some insect pics but they only really make my Mom happy.

5 to 1?? Now, you probably don't mean lunchtime, do you?

On the film, perhaps twice life size is as far as I've gone.

I have a long way to go, which I find jolly exciting. :D

(this lens has a standard 45mm parafocal distance). The iris is not designed to stop all the way down and its main purpose is to prevent/limit stray light from entering the optic and to match the numerical aperture of the condenser. The standard tube lengths on all older microscopes is 160mm and there is no problem using this lens on 160TL microscopes. Ideally this lens is designed to be used with Leitz/Leica Periplan oculars (eyepieces) but it will work with others, but lens aberrations may not be fully corrected. Projection eyepieces are best suited to photomicroscopy but you can use conventional ones (Leitz photomicrography eyepieces have a red dot and that how you distinguish them from conventional ones). You could use this lens without an eyepiece on a camera bellows but you would need to experiment with lens to film plane distances etc.

rjlittlefield
Site Admin
Posts: 23564
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

Thanks for the additional information. This helps a lot.
The lens is the one with the pretty rectangle in the link, 32/0.3
I was afraid you were going to say that.

The short story is that you have bitten off way too much to chew at one time.

Set aside the microscope objective for a while. Practice working with your other equipment until you can comfortably handle stacks shot at 5:1 onto the sensor using an enlarging lens reversed on bellows. When you get good at that, then move to a low power microscope objective (10X), and after you get good with that, move to higher powers.

Adding a few details...

The fundamental problem with small subjects is diffraction. It sounds like you may still be thinking that you can just stop down to get more DOF. With small subjects, that doesn't work. Diffraction makes the image hopelessly fuzzy long before you get enough DOF to worry about. To get a sharp image, you have to use a wide aperture. The wide aperture combines with higher magnification to give minimal DOF. It's just like a microscope -- all you can see clearly is a thin slab of your subject at any instant.

The only practical cure for the DOF problem is focus stacking -- shoot a bunch of pictures focused at different depths and let software piece them together to give a single image that's well focused everywhere. But to make this scheme work, you have to shoot the stack, which means being able to change focus by tiny steps.

The step size varies with magnification. At low magnifications, say 20 mm across the field using a 1:1 setup, you might step by a full mm. But at high magnifications, say 1 mm across the field using a 20X microscope objective, you can only step by a few microns (a few thousandths of a mm). Some mechanics are needed even at low magnifications. At high magnifications you need a microscope stage or its equivalent.

In addition, you'll have vibration to contend with. Like everything else, the importance of vibration scales with magnification. An amount that is insignificant at 1:1 can be completely intolerable at 10:1. So you'll need to be careful with the mechanics, and probably shoot with electronic flash too.

Good work at 5:1 (4 mm across the field of a typical DSLR) can be done using enlarging lenses and bellows. Go read http://www.photomacrography.net/forum/v ... .php?t=424 and study the gobs of other related topics that have been posted since then in the technical forums.

Hope this helps,
--Rik

Charles Krebs
Posts: 5865
Joined: Tue Aug 01, 2006 8:02 pm
Location: Issaquah, WA USA
Contact:

Post by Charles Krebs »

Chris,

This is a rather uncommon objective. I don't know much about it either, but I'll second everything Rik mentioned.

This is too much magnification to start out with. The bottom line when using any of these objectives as a "macro" lens on a bellows is what the results look like. It states that it was meant to be used with corrective eyepieces (Periplan). If you put it on a bellows, extend the bellows to about 160-170mm (base of objective threads to sensor), and you find that...
the Chromatic aberrations are psychedelic, and field curvature is deep.
... it's not a good sign. :cry:

I recently posted a small article about objectives on bellows here:
http://www.krebsmicro.com/obj_bellows/index.html

It doesn't go into great detail, but there might be something in it for you.

The search function of this forum works well. There is a large amount of information here if you take some time to look for it.

Charlie

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

Now I've bought this:
It was expensive so it must be good, right? If I tape a yoghurt pot to the front of it and glue it to a body cap will it be OK? Wil I need to paint the yoghurt pot black?http://img11.imageshack.us/img11/6943/116034e453446.jpg

Seriously folks, I thank you for your time. I seem to have not conveyed that I have realised difficulties since getting the lens - and partly as a result of finding this forum.
Yes I understand NAs, dof, diffraction and stacks, to an extent, and had already read the articles suggested and a host of others, and there's masses online.

The question to which perhaps I should have restricted myself, is whether non Plan, plain Achromat objectives are usable on a camera without an additional lens such as an ocular, for correction? I see from the literature that Leitz ob lenses of this type should all be used with a Periplan ocular. There seems to be basically one Periplan. So should the lens in question be "Worse" for direct use than the others?

For the moment, I'm happy to constrain myself to 2 dimensional subjects, but if nothing else this exercise has demonstrated how meagre a DOF of one thou, actually is. :shock:

Charles Krebs
Posts: 5865
Joined: Tue Aug 01, 2006 8:02 pm
Location: Issaquah, WA USA
Contact:

Post by Charles Krebs »

The question to which perhaps I should have restricted myself, is whether non Plan, plain Achromat objectives are usable on a camera without an additional lens such as an ocular, for correction?
Certain plan (and non-plan) achromats certainly are, but a great many are not. No single, simple answer. You have to try the specific objective. The Nikon CF's work great. The Nikon CF biological objectives above 10X have working distances that are too short to be of use, but the CF M Plans are available in a variety of working distances. Generally (except for a 4X) apo's have unusably short working distances. (The key exception to this would be some infinity-corrected series like those made by Mitutoyo. But these require a tube lens.)

Objectives that "required" corrective eyepieces did not have a standard amount or type of correction between manufacturers (and sometimes even within a manufacturers offerings). In addition to chromatic correction some also dealt with field flatness issues. When you use a microscope objective you essentially sacrifice DOF for resolution. Image stacking becomes a necessity if you expect any sort of "normal" pictorial result. As a result, if the curvature of field is not too large it is not a huge issue if stacking it to be performed.

Chromatic aberration will also vary tremendously between objectives. Some show fairly low levels and are quite usable, especially with the CA correction available in software these days. (Naturally it's best to avoid it as much as is possible with proper optic selection). When you initially said:
the Chromatic aberrations are psychedelic, and field curvature is deep.
I took it to mean that you found both characteristics unacceptable. (A picture or two would be far more helpful if you want an opinion.)
I see from the literature that Leitz ob lenses of this type should all be used with a Periplan ocular. There seems to be basically one Periplan. So should the lens in question be "Worse" for direct use than the others?
Yes.

The problem is that you can track down an eyepiece or a photo-type projection eyepiece but it will be an additional expense and complicate the setup. With a projection eyepiece you will need a very long bellows/tube configuration to set it up properly. With a "conventional" Periplan you should be using the afocal method, which means a camera lens on the camera body looking directly into the eyepiece. (Not always easy to do without getting severe vignetting).

And even if you go through this additional expense and set-up, who knows what the results will look like. This objective was originally designed to be used with a universal rotating stage with a polarized microscope. These are used to study crystal and rock specimens that are held between two hemispherical lenses.
(See botton of this page: http://www.olympusmicro.com/primer/anatomy/stage.html)

They are similar to the objectives discussed in this thread:
http://www.photomacrography.net/forum/v ... sc&start=0

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

Thanks again Charles.
Yes Ill do some test shots. You'll not be surprised to hear another 10 buck lens has arrived, a LWD 20/0.3, so I can compare them, before they probably both go on ebay.

Unfortunately Rik's "CF N Plan Achro 10X NA 0.30 microscope objective. That objective, which cost $100" isn't popping up every day..

One point I'm not sure on - I see that objectives are designed for cover slips, and why, but the Leitx lens is a bit ambiguous (to me) about whether it "needs" one or not. If it does, and assuming I hava quartz the right thickness, could it usefully go in air, between sublect and lens? Of course they're always shown in contact with the subject, with one less air/glass interface? Photography might be an unlikely use, but I could always LOOK at things!

I spent some years using microscopes but treated them as my wife does a car. If it works...
Somewhere I have some pics I did of insects, produced by misappropriation of a scanning electron microscope. The tedious bit was plating them with gold by vapor deposition. I seem to remember them collapsing. DOF to die for, but all spooky shades of grey.

rjlittlefield
Site Admin
Posts: 23564
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

ChrisR wrote:One point I'm not sure on - I see that objectives are designed for cover slips, and why, but the Leitx lens is a bit ambiguous (to me) about whether it "needs" one or not.
It is odd that the manual you link says that bit about with/without the quartz plate. There are other aspects of that document I don't understand either, notably why the same objective has listed different magnifications and apertures for "engraved", "in transmitted light", and "in incident light".

That other document I referenced, describing the Leica heating stage, says that "With objective series N PLAN H the quartz glass of the heating stage, which is 1.8 mm thick, is integrated into the optical calculation, e.g. objective N PLAN H 20x/0.40 Q 1.8, FWD 10.6 mm; objective N PLAN H 50x/0.50 Q 1.8, FWD 7.1 mm. For objective magnifications less than 20x standard objectives from the range can be used." That statement makes sense to me, since for low NA objectives, the impact of 1.8 mm of quartz could be tolerated albeit with some degradation. The NA's are lower in the manual you linked. Perhaps they just consider that all those lenses have low enough NA to get away with it. In that case we're still left to wonder exactly what is causing the psychedelic aberrations and field curvature. Mysteries abound...
If it does, and assuming I hava quartz the right thickness, could it usefully go in air, between sublect and lens?
I think so, assuming you could hold the thing perpendicular to the optical axis. But I might have the theory wrong, and I've never had equipment to run a good experiment.
Somewhere I have some pics I did of insects, produced by misappropriation of a scanning electron microscope. The tedious bit was plating them with gold by vapor deposition. I seem to remember them collapsing. DOF to die for, but all spooky shades of grey.
You might be interested in this topic, "Revisiting the yucca moth: stacked macro vs SEM".

--Rik

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

INteresting stuff.

"Mysteries abound"
Only when you know what you're talking about :wink:
It often seems to me that when dealing with the unknowing people :oops: you have to build in the F factor. "Fudge", "finger", or anything beginning with the same letter.

I can supply a non-Drosophila organism suitable for study of neurodegeneration. I'll just go embed my head in wax..

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

Have I just dug hole I'm in a little deeper, or will this help me see the bottom?
Vendor described it as a Periplan:
Image

It's a -ve lens.

"Try it" I hear you say! Yes I shall, but I'm still working out how to bolt the Deardorff to it.

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

Seriously - how would this be connected to a Nikon body?
The larger black part rotates, and has a knurled screw on the back.
If I understand correctly, standard microscope adaptors wouldn't work on this. ??
From what I read of simiilar though not identical "eyepieces", the image would be about 60mm from the top. Does that sound right?

rjlittlefield
Site Admin
Posts: 23564
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

"Have I just dug hole I'm in a little deeper, or will this help me see the bottom?"

Deeper, I think.

I've never held one of these eyepieces in my hands, so what I'm writing is from reading, inference, and a bit of speculation.

Projection eyepieces are designed to take light that would otherwise focus to an image about 10 mm inside the microscope tube, and refocus it in the camera sensor plane some distance outside the tube. Magnification is quoted as the ratio between the image projected by the eyepiece outside the tube and the image inside the tube with the eyepiece removed.

You say that this eyepiece is a negative lens. That means it will be working like a teleconverter on an SLR camera, intercepting the light before it comes to a focus at all, and refracting it to focus into a larger image farther back, but not inverted again.

To use this beast with a camera, you would have to figure out how to hold it steady at the proper distance from the sensor plane, with the objective held steady at the proper distance in front of it. Then you have to figure out how to keep the whole thing from vibrating while taking what will turn out to be a rather high magnification picture.

I believe that "P4X" label means that this eyepiece is designed to give 4X enlargement. You can change that somewhat through lens positioning, but image quality will probably degrade. At nominal 4X, combined with even a 10X objective, you'd be at 40X onto the sensor -- not a good place to start.

And you're right that standard adapters won't work with this lens, so you'll be dealing with custom mechanics too.

My suggestion would be to carefully wrap this lens, put it with the strange objective, and preserve the pair of them for resale while you pursue a more conventional learning curve. But of course that recommendation may be worth exactly what you paid for it. :)

--Rik

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

Rik wrote:Deeper, I think.


Deep gloom.
Deeper, Madder and Truer? Like any infatuation, destined for divorce and destitution? I'll try not to let it get that far. The plumbers' merchant could be the next port of call.

I ventured to the great outdoors, well the great back door, in search of bugs, but they're not in season, or they heard me coming. All I found was mealworms, this guy's lunch, which we'd put there.

Oh well, at least the journey has taught me that mealworms are Choleoptera larvae :P

rjlittlefield
Site Admin
Posts: 23564
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

ChrisR wrote:Oh well, at least the journey has taught me that mealworms are Choleoptera larvae :P
At the risk of arrant pedantry, it's "Coleoptera", no "h". Unfortunately, Google will not volunteer the correct spelling -- it just returns 198 hits instead of the proper 2,900,000.

Sorry if my take on your lens sounds gloomy, but it's a bit of "been there, done that". The details are different, but the general flavor was the same. Some paths are just way more trouble to take than are justified by either the destination or the views along the way.

--Rik

Post Reply Previous topicNext topic