[infosyn]

I'm thinking of getting a "low power" (10x - 50x range) medium-quality ($400-$1000 range) stereo microscope, sometimes called a dissecting scope, for looking at mosses, insects, and tidepool critters, and would sure like to be able to use a K-7. Anyone out there have words of wisdom?

1) Would it be better to use a specialized digital camera with the stereo microscope, instead of trying to mount a K-7 on it?
2) Is a "trinocular" model the best way to mount a camera?
3) Any recommendations on brand of stereo microscope to get?
4) Any recommendations on a source for the stereo microscope or the adapters?

[Blue]

The trinocular configuration is the best way. Just make sure you have the appropriate photo tube and of course t-adapter for Pentax K. I have several digital CCD cameras that can work with my scopes as well as independently with the c-mount lenses. I even have an adapter to let my use my K-mount lenses on them. However, there is no reason not to use the K-7 on a scope. I haven't used the K-7 but I have used my K20d and Nikon 70s body. For still images, I prefer the dSLR Pentax bodies. Your price point will be tricky but doable. Don't rule out used scopes. Leica and Meiji and even older B & L (assimilated in the past decade or so by Leica). I wouldn't bother if it didn't have the trinoc though.

[newarts]

The trinocular configuration is the best way. .....

I agree. I use a binocular scope and swapping the camera in & out is a pain in the neck.

I've found P&S cameras to give excellent results when simply placed over a microscope's eyepiece. I added a 29mm male filter thread to an extra eyepiece & secured a female 29mm filter thread to the camera. This makes swapping the camera in & out easy.

[sholtzma]

Don't know if this will help, but here goes....

I once looked into getting a good microscope to do photomicrography. I ran across the following advice online (given to someone else) that I kept handy. Here it is in full:

Leitz never made a bad compound microscope that I ever heard about. Even the student microscopes that teaching laboratories ordered by the hundred in those years were optically very good. But to take good pictures with a compound microscope you need the right equipment. Good for eyes is not necessarily good for film. Using it as you did you could not approach the results you'd could get with a phototube - and if possible a photo-eyepiece (flat field) and a planachromatic objective.

The Zeiss series of Photomicroscopes have a large number of air-glass interfaces, but the instrument is designed for photomicrography. Binocular tubes are definitely not. This does not mean you can't get images - just that they won't be very good.

You say the act of putting a camera on the microscope wouldn't have any effect on the image. If putting a camera on the binocular eyepiece is good enough and makes no difference, why are phototubes and photo optics made at all? What you say is partly true. But - what the eye sees, and can handle, is not what the camera sees.

We all know the human eye/brain is a remarkable piece of analytical equipment - it's an image processing system. Film on the other hand records one, or a number, of static images. Analysis has to take place later. While looking at a specimen under the microscope the observer moves the specimen stage all the time. The fine focussing control is also used continuously as the observer gathers more information. The field is rarely flat, except with very expensive optics. But while focussing the scientist doesn't even notice this. If he took a picture he'd notice it very soon. Some part of the field - the periphery or the centre - would be out of focus at magnifications of more than 100X or so. To discuss this fully would take an awful lot of off-topic wandering.

The Leitz Microscope you have is probably one of the best of its kind for the time. Get a phototube and a photo-eyepiece - if possible a few planachromatic objectives and you'll get very good images.

And of course we now get back to larger format. Why? Unless the image is big there is no point in using bigger film. No modern photomicroscope uses film bigger than a 70 mm roll (1975 or around that time). And the roll film is only used at lower magnifications where larger pictures are needed. At the limit of the resolution of the light microscope - about 1250X - the image is still only the size of the exit pupil of the microscope - a few millimetres across. On your piece of 35mm film you have the highest magnification possible. Any further blowing up, onto 4 x 5 or anything else, is what microscopists call "empty magnification" and is a waste of time and degrades the image. Unless you want to make prints or posters to put on the wall of your lab there is no point in enlarging more. And if you did you couldn't get more detail from 4x5 than from 35 mm. However, when very low magnification objectives and eye-pieces are used, for huge specimens such as biological sections a few of millimetres across, putting a 4 x 5 camera with a bellows three feet long (and the kitchen sink) on photomicrographic equipment made for the purpose - and it was in the good old days - gave some advantage. But note: I'm not prepared to discuss this particular subject again. The Zeiss photomicroscope models I had in my lab only had 35 mm equipment. The bigger ones (70 mm) had already been discontinued by the time I bought them. I don't know what's available now.

Nightingales have a lot of equipment. I'm sure they'd have a phototube to fit your instrument. All the Leitz microscopes have standard interfaces. They might have photo-eyepieces as well. But when you get this stuff and start doing serious work don't use the camera shutter for your exposures. Get everything right - focus, composition, exposure time and so on - and then turn off the microscope light. Open the shutter and after half a second turn the microscope light on and off to make the exposure. Vibration from the mirror and shutter can ruin a picture if the camera is in physical contact with the microscope frame. Unless it's a particularly rigid one made
for photomicrography. If the exposure is several seconds long vibration (from the shutter or mirror) won't matter and this is where the LX might come into its own. But you have to sit still while the shutter is open. This how I'd do it - long exposures controlled by the LX metering system.

The actual diameter of a transmission microscope ocular tube is one inch (25.4 mm). The microscope adaptors are made to fit tubes from about 25,0 to 26,0 mm in diameter. They utilise a collet that closes down on the tube. Tubes vary slightly, but the big names - Zeiss, Leitz, Wild (Wild belongs to Leitz now) are usually the same - 25,4 mm. The ocular tubes of stereo microscopes are 33 mm in diameter so the K adaptor would be useless. Very good pictures indeed can be taken with stereo microscopes. It is quite practical to attach a camera directly to one of them with a phototube; but not to a transmission instrument - if you want decent pictures.

First of all what are your specimens going to be like. Sections of plants?
Small solid objects? Seeds, shells, tiny animals, micro-organisms, insects, pollen grains (these are great, often having beautiful sculptured detail on the surface), protozoa? A microscope suitable for a blood smear, animal tissue sections, bacterial cultures, protozoa and the like would be a transmission instrument with a condenser of NA 1.4 and a set of objectives say 4X, 10X, 40X and 100X oil immersion; two pairs of eyepieces - 8x and 12X would do - very expensive purchase indeed.

If you want to take pictures of small solid objects, say between 0,1 mm and 10 mm in size a stereo microscope would be suitable. The barrels of these instruments have a diameter of 33 mm - Leitz, Zeiss, Wild, Reichert, Olympus, Nikon and such, are all the same. Pentax will make an adaptor for this size as well as one for transmission instruments which are smaller - 26mm.

Transmission microscopy always involves the preparation of the specimen in a laboratory. It's not something that can easily be done by a beginner. Using a stereo microscope is much easier, you can use it to look at anything that will fit on the stage, or not if you have the right support. Limited transmission is also possible. But remember this - at final magnifications - more than about 5X you will have hardly any depth of field. There are ways around this problem, but all are very complicated and expensive. A Wild M1, a simple student instrument will give a range of magnifications from about 5X to 80X and be the most suitable for a start. You'd need good lights, at least two and a couple of reflectors perhaps. Most labs use halogen lamps with fibre optic light guides these days - expensive things. But tell us what you have in mind. If you don't know, as I didn't when I first started this at 15, it can be frustrating.

Cheap Chinese or Russian microscopes should be avoided at all costs. The good ones will cost a few thousand dollars, but for a few hundred you might get a nice instrument on eBay - a Wild or Leitz with a couple of sets of eyepieces and a magnification range of 5X to 250X. I saw one a while back. There was also a Nikon transmission instrument, starting at a few hundred dollars that was, in my opinion, worth at least $5000. The seller had no idea what he was dealing with and thought the small bottle of immersion oil in the case was for "cleaning lenses". By the way, the mechanical parts of a microscope are very important. If it shakes, or the focussing mechanism has backlash, or the optical system doesn't line up, you can forget it. It would be like using a pair of binoculars with a loose prism.

Remember this though: the results will always be a bit disappointing. What you see with two eyes is always more impressive than a picture taken through one of the tubes.

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Last edited by sholtzma; 03-31-2010 at 08:36 PM.

[Blue]

Sholtzma, the OP specifically asked about stereoscopes a.k.a. dissecting scopes which also come in trinocular configuration to accept photo tubes.

That said, this was taken on an Olympus compound darkfield scope equipped with a phototube and slr body. It is a 2.5mm wasp mounted on a microscope slide with cover slip. It was lightly colored and clearing was satisfactory with chloral hydrate.

[openyourap]

. . .

1) Would it be better to use a specialized digital camera with the stereo microscope, instead of trying to mount a K-7 on it?
2) Is a "trinocular" model the best way to mount a camera?
3) Any recommendations on brand of stereo microscope to get?
4) Any recommendations on a source for the stereo microscope or the adapters?

1) A specialised camera will allow for tethered shooting, and the smaller format of a dedicated (usually c-mount) camera will provide a greater depth of field, which is razor thin in micro-photography.
2) Trinocular is the most convenient if you're starting from scratch, though you could try digiscoping down one of your eyepieces of a binocular/monocular scope if the exit pupil is large enough. Again, smaller format P&S cameras are at an advantage here. With sufficient light, you can get quite good results at low magnifications using this method.
3) On your tight budget, you're looking at an old second-hand name-brand, or new non-branded scope. Computer design and manufacture of lenses has significantly closed the quality gap that once existed in the market, so I wouldn't write off the generics. With a new generic, you'll get the advantages of more modern lens innovations that even the quality brands didn't have 20 years ago. Of course, if your budget allows, go for a new name-brand.
4) If B&H or Adorama don't have what you're after, microscopy lab suppliers like Proscitech carry a decent range of this kind of specialist equipment.

[infosyn]

OK, folks, thanks for the excellent advice. It's now clear that my cost estimate was too low, and that a stereo microscope for high-quality photomicrography is more like $2300, rather than $1000 (new). Haven't yet decided whether to venture into that range. (Used is not an option for me.)

If/when I get one, I'll update this thread with first-hand discoveries. Until then, here's what I've found:

1) Would it be better to use a specialized digital camera with the stereo microscope, instead of trying to mount a K-7 on it?

Sounds like using a 14MP sensor on a stereo microscope is serious over-kill, but I already have the K-7, so the added cost would be just for the adapters, which are around $300. I expect that K-7 firmware features such as HDR, video, and auto interval shutter could be very useful, so I'll go that route to begin with. I don't see that the specialized cameras offer anything that the K-7 doesn't.

Apparently there are ways to mount a P&S digicam on a stereo microscope and still use the digicam's lens (focussed on infinity); I did not investigate this route. To use a DSLR, obviously, you need to remove the camera lens, thereby losing all auto-focus and aperture control.

All the special cameras are lower resolution than the K-7, some MUCH lower, even the expensive ones. Also, apparently some of the special cameras require a USB-tethered computer running Windows software, which for me would be unacceptable. YMMV.

2) Is a "trinocular" model the best way to mount a camera?

Consensus is, trinocular is very convenient and certainly worthwhile. Incidentally, some of the Meiji scopes toggle (via prism) between the left eyepiece and the camera, while on other Meijis all three ports are always enabled (beam splitter) so you can watch through both eyepieces at the same time you take photos -- very handy although you sacrifice some brightness thereby.

3) Any recommendations on brand of stereo microscope to get?

There's clearly a huge gap in image quality between $300 Celestrons and $500 Omanos, and $2000 Meijis. There's apparently NOT much difference between a $2000 Meiji and a $5000 Leica these days, which is why the extensive Meiji stereo microscope line is the real workhorse.

4) Any recommendations on a source for the stereo microscope or the adapters?

Surprisingly, B&H doesn't sell microscopes. Adorama and Amazon have only stuff in the $300 range. For the decent stuff, you'll need to go elsewhere.

Meijis are available from some 200 dealers around the world. Most of the dealers in the US do not keep a full selection in stock, since the scopes are so expensive, so you can't expect to walk in and try out several models, and anything you order would simply be drop-shipped to you from the Meiji USA importer in San Francisco.

Meiji scopes are not available at retail directly from Meiji USA, although you can get an hour of very credible pre-purchase advice over the phone, and extensive technical support from them. As you would expect, without competition from Amazon/B&H/Adorama, dealer prices are only 10% or so below list price.

[Rorschach]

I'm resurrecting an old thread but here goes...

The best microphotography tools among the stereo or dissecting scope types that are intended to look at 3D objects/specimens would be the Wild (Leica) macroscopes due to their optical path which is completely optimized for imaging. That's the sole purpose of those instruments! And that is no typo, they are called _macroscopes_, not microscopes. They do also have a binocular head with eyepieces for viewing but the image you see is not 3D stereoscopic, unlike on any "normal" stereomicroscope. It is 2D just like the images. There's a few models but the best ones with APO zoom objectives will cost you 1500 euros to 3000 euros used, depending on what auxiliaries come with it. That is the Rolls Royce of 3D reflected light imaging microscopy (as opposed to light microscopy using glass slides and thin specimens plus light going through the sample)

But there are very good quality cheaper options, especially with the Wild / Leica system which has unparalleled modularity and very good optical quality combined with top workmanship and materials (especially the old Wild scopes). Stay away from the Russian and Chinese cheap options unless you have literally no budget.

I am currently building a hobby microphotography system around my Wild M7S, the Wild HV trinocular phototube and Pentax K5 IIs. A special -and important- bonus of the M7S compared to many other Wild scopes and other makes is that one can use the objective on two distinct positions. Firstly on the middle for normal work through the eyepieces with full 3D view and secondly slightly displaced to one side (the photo position). In the second position the light travels on a single path instead of two, and this takes away parallax problems, most of the chromatic aberration problems and also gives higher resolution for the images.