William, 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 35 mm 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. Dr E D F Williams http://personal.inet.fi/cool/don.williams Author's Web Site and Photo Gallery Updated: March 30, 2002 ----- Original Message ----- From: "William Robb" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, December 20, 2002 12:13 AM Subject: Re: Advice for a microscope for photog. purpose? > Conversation interspersed. > ----- Original Message ----- > From: Dr E D F Williams > Subject: Re: Advice for a microscope for photog. purpose? > > > > A binocular stereo microscope has two separate objectives. A > transmission > > light microscope a 'compound microscope' has one objective, > but may have a > > binocular head, or even a head with a binocular and a vertical > photo tube. > > The beam is split and 50% goes to each ocular. But both eyes > see the same > > view. In a stereo microscope the eyes are seeing a true stereo > picture > > through two separate objectives spaced some centimetres apart > and focussed > > (angled) at the same spot in the centre of the stage. > > I figured that out, even as I hit send. > > > > The magnifications obtainable with a good compound microscope > approach the > > theoretical limit of about 1250X for visible light. Stereo > microscopes work > > between 5X and 200X although some go higher. Anything about > 150X is > > impractical. > > This is a very good instrument, I think. My father in law used > it at the cancer lab he managed, and when he retired, they gave > it to him as a going away present. > It is called a Leitz Wetzlar, and would have been produced in > the late 1970's, or thereabouts, possibly into the 1980s. > > > > By putting a camera on one of the oculars (eyepieces) of your > microscope you > > got 50% of the available light, but also added noise to your > picture > > from reflections inside the unused side of the optical system > and the beam > > splitter and prism. There are at least ten glass surfaces that > would have > > been bouncing light up and down the tube. The only way to take > decent > > pictures > > with a compound microscope is through a vertical phototube > without any extra > > glass surfaces to degrade the image. > > This makes me question the usability of any microscope of this > type for any purpose at all. The act of putting the camera onto > the instrument isn't going to have any effect, either good or > bad, on the quality of the image, or the degree of flare from > stray light. I can only presume that what you are telling me is > that this type of microscope is fatally flawed. > I have been seeking a phototube for it, but alas, with no luck > as of yet. > If as you say, the design is flawed to the point of being > unusable, I will stop looking. > It does surprise me that a company with Leitz Wetzlar's > reputation would put crap onto the market, especially the > medical research lab market. > > > > > I've just had a look at Microscopes from Nightingales in > Florida. They have > > a number of beautiful instruments for sale. Many have solid > stands that > > would support a camera perfectly well. There is even one, a > Leitz Ortholux, > > with an automatic camera included. I think it was about $3500 > and quite > > reasonable at that. Perfect for an amateur who is really > serious about the > > job. The objectives and eyepieces included were Planachromats, > specially > > made for photomicrography. There were a few others like the > fine Zeiss GFL > > ( I had two of those) but they don't support cameras very > well, an external > > stand is always needed. > > For that kind of money, I would forgo anything that would be a > 35mm accessory, in favour of a bigger format. > > > > Quite a few of the instruments offered are modern enough so > that it would be > > possible to buy a vertical phototube to which the Pentax K > adaptor could be > > fitted. An LX would be the ideal camera for the job. > > That it is. > > William Robb > >
