Re: Advice for a microscope for photog. purpose?
- Original Message - From: Dr E D F Williams Subject: Re: Advice for a microscope for photog. purpose? Dr Williams: Thanks for the explanation and advice. The set-up I showed does work, and seems to work fairly well, but I have no idea how much better it could be with a phototube on top. From your explanation, I would think lots, which I find intriguing. Regarding why large format, it's because I am more interested in it than I am in microphotography, and hence would buy an 8x10 for landscapes and portraits before an expensive piece of equipment for micro work. However, if I could get a phototube for the Leitz at a reasonable cost, I would certainly consider that. You mentioned a Nightingale's. I presume this is an online seller? If so, can you supply a URL to me? Thanks William Robb
Re: Advice for a microscope for photog. purpose?
- Original Message - From: Dr E D F Williams Subject: Re: Advice for a microscope for photog. purpose? The binocular head that camera is attached to belongs to a transmission light microscope not a stereo instrument. And to get a decent picture with that arrangement would be very difficult. I seriously doubt it would work very well. That was the set-up I used for my film granularity tests. It worked well enough for that purpose. Here is a sample from that set-up. http://users.accesscomm.ca/wrobb/Superia100/ Also, could you explain the difference between a transmission light instrument and a stereo instrument. I was under the impression that because the instrument has 2 eyepieces, it would be considered a binocular. William Robb
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. 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. 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. 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. 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. 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: Thursday, December 19, 2002 2:12 PM Subject: Re: Advice for a microscope for photog. purpose? - Original Message - From: Dr E D F Williams Subject: Re: Advice for a microscope for photog. purpose? The binocular head that camera is attached to belongs to a transmission light microscope not a stereo instrument. And to get a decent picture with that arrangement would be very difficult. I seriously doubt it would work very well. That was the set-up I used for my film granularity tests. It worked well enough for that purpose. Here is a sample from that set-up. http://users.accesscomm.ca/wrobb/Superia100/ Also, could you explain the difference between a transmission light instrument and a stereo instrument. I was under the impression that because the instrument has 2 eyepieces, it would be considered a binocular. William Robb
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
Re: Advice for a microscope for photog. purpose?
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
Re: Advice for a microscope for photog. purpose?
What a question. You should use a Pentax microscope. Of Course! GRIN Ciao, Graywolf http://pages.prodigy.net/graywolfphoto
Re: Advice for a microscope for photog. purpose?
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. If we are to go on with this, its going to be a rather long and way off topic. The camera itself plays a rather minor role in this work. I've found a picture of my very first photomicrographic equipment in the Encyclopaedia of Southern Africa where there is an article I wrote on protozoa in 1970. The equipment is more or less like that I expect you envisage using. But perhaps this should be continued off-list? Unless there are more people interested. I don't know how we can show the picture unless I email it to those who want it, or post it. But in any case it still has to be scanned. Don 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: mike wilson [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Wednesday, December 18, 2002 2:35 PM Subject: Re: Advice for a microscope for photog. purpose? Hi, Don wrote: The K wouldn't fit anyway, it is made for 26 mm tubes. 25mm I suppose there are some optics involved. None in mine. It is just an adaptor with a K mount at one end and a clamp tube at the other. From the manual: As a binocular microscope has two lens tubes, slanted towards the object, no camera, can take photographs ... because the resulting images will be blurred. Used by itself, the Adaptor K will give images approximately one third of the microscope enlargement on film. It can be used with extensions or bellows to give images up to the full enlargement size on film but this necessitates using some form of camera bracing to ensure stability. Enlargements over x600 are not recommended for the adaptor. To return to the header topic; another source of microscopes might be a local educational establishment. It is possible it might loan you a suitable 'scope in return for some slides/prints. mike
Re: Advice for a microscope for photog. purpose?
Thanks Don. I'm a true beginner, so I should go on the WEB trying to get some basic instruction about microscopes, lighting etc. First of all what are your specimens going to be like. Sections of plants? Small solid objects? Seeds, shells, tiny animals, insects, Possibly all those. pollen grains (these are great, often having beautiful sculptured detail on the surface) Interesting... Very variable in size I guess. 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. 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. Transmission means light passing through the specimen? 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. I'll live with litle depth of field... 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. Any web site showing / explaining different products and settings, or names of eBay items? 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. I can do macro with bellows up to about 5x, so next step is going from 5x up. I don't need to go very far after that. I'd like to be able to show parts of plants, fibres' structure: wood, paper (with and without ink). 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. So this is a price without objectives? (I already have Mplan 5x and 10x.) 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. Because it is not stereo anymore... So I'll close one eye to loose the stereoscopic vision, a thing I often do while looking for a photograph. Andre --
Re: Advice for a microscope for photog. purpose?
- Original Message - From: Dr E D F Williams Subject: Re: Advice for a microscope for photog. purpose? The ocular tubes of stereo microscopes are 33 mm in diameter so the K adaptor would be useless. http://users.accesscomm.ca/wrobb/LX_K_Bino.jpg Seems to work. William Robb
