July 17, 2006... This article was assembled in January 2005. After a 40+ year hiatus, I had reintroduced myself to microscopy, and this page discussed the way I had set up my equipment. In the year and a half since, some things have changed, while other were retained. I have changed my stand, and now use an Olympus BHS. The primary reason was an opportunity to obtain DIC capability. This change, and additional experience, prompted some modifications.
Since this page has been visited a surprising number of times, and all of the information is valid, I will leave it up as originally written. I will be writing an updated version this summer that will illustrate my current arrangement and the changes that have been made. When this is completed I will again update this addendum, and provide the link.
While not developed yet, I also have a microscopy site that provides some galleries and articles. That address is:
http://www.krebsmicro.com
October 9, 2007
The revised version of this page showing my current microscope arrangement can be found here:
The revised version of this page showing my current microscope arrangement can be found here:
In grade school I had a Swift microscope and spent many hours looking at just about anything that would fit on the stage. As I got into high school, college, army, marriage, raising five kids, and more; microscopy took a back seat to other aspects of my life. Not too long ago I decided to once again get a microscope and explore.
This page provides a brief description, and photographs, of the way I have set up my microscopes. I claim no great experience or special qualifications as far as microscopy is concerned, but hope that sharing some of the methods that have worked well for me might be of some interest, and help, to others getting involved in this area.
One of my primary goals is photomicrography. Photography is one area where I do have a great deal of experience, and have done a great amount of photomacrography over the years. So when I purchased my first microscope, there was at hand a large amount of photo related equipment that could be put into service. I had originally intended to use my film cameras, but as soon as I began working with my Canon 10D digital SLR the huge advantage of seeing the image as soon as it is taken became obvious. I’ve yet to take a picture on film!
The equipment is set up in a manner “traditionally” used with 35mm SLRs. The camera body (no lens attached) is positioned over a photo-eyepiece that is in the trinocular tube. I have two microscopes set up side by side this way, using heavy-duty copy stands. The microscopes are set on the baseboards. The picture below shows the overall setup of the two microscopes.
This page provides a brief description, and photographs, of the way I have set up my microscopes. I claim no great experience or special qualifications as far as microscopy is concerned, but hope that sharing some of the methods that have worked well for me might be of some interest, and help, to others getting involved in this area.
One of my primary goals is photomicrography. Photography is one area where I do have a great deal of experience, and have done a great amount of photomacrography over the years. So when I purchased my first microscope, there was at hand a large amount of photo related equipment that could be put into service. I had originally intended to use my film cameras, but as soon as I began working with my Canon 10D digital SLR the huge advantage of seeing the image as soon as it is taken became obvious. I’ve yet to take a picture on film!
The equipment is set up in a manner “traditionally” used with 35mm SLRs. The camera body (no lens attached) is positioned over a photo-
On the left is a Meiji 2000. This was purchased in mint condition on eBay in April of 2004. Not a lot of panache with the microscope cognoscenti, but it’s a good quality, Japanese-made microscope. Unfortunately it took me a while to sort out the objective choice, but I am now extremely happy with the performance of a set of Olympus S Plan Apo’s. The photo-eyepieces used are the Olympus NFK series designed to be used with these objectives. The microscope on the right is a Nikon Labophot that is set up for phase contrast. It uses Nikon CF N Plan DL phase objectives. The photo-eyepieces used with this scope are the Nikon CF series designed to be used with the objectives.
The camera is attached to a bellows, which in turn is attached to the copy stand. The first step in setting this up was to insure that everything was level. Using an accurate bubble level I made sure that base of the copy stand was level (in both the x and y direction). Then I insured that the microscope stage, and the camera mount on the bellows were also level.
The bellows is actually used as a “shade”. Racking it closed allows access to the photo-eyepiece (see right). When it is extended, it moves over the trinocular tube to effectively shield out any light other than that coming through the microscope. It’s a tight fit, but there is no contact between the bellows and the microscope. This effectively eliminates the transmission to the microscope of any vibration that might be induced by the mirror or shutter movement of the camera.
In the picture above, you can see the small TV that I use to view the picture that I have just taken, along with it’s histogram (which gives vital exposure information). This TV is simply connected to the “video out” on the camera body. The TV is only used for compositional and exposure purposes, not to try to judge focus. I do not use a computer and software to control the camera. I can reach up and quickly access the display buttons by feel. It becomes second nature after a short time. The mouse you see in the above picture has been wired into the camera release. The left mouse button releases the camera shutter. The right mouse button serves the same function as pressing the regular Canon release half way. (A second “mouse” is wired into the release and is fastened to a board on the floor and used as a foot switch for times when both hands are occupied). To the left of the mouse is a box that controls the output from the Vivitar 283 flash that can just barely be seen at the back of the microscope base (more on that further on).
In the picture above, you can see the small TV that I use to view the picture that I have just taken, along with it’s histogram (which gives vital exposure information). This TV is simply connected to the “video out” on the camera body. The TV is only used for compositional and exposure purposes, not to try to judge focus. I do not use a computer and software to control the camera. I can reach up and quickly access the display buttons by feel. It becomes second nature after a short time. The mouse you see in the above picture has been wired into the camera release. The left mouse button releases the camera shutter. The right mouse button serves the same function as pressing the regular Canon release half way. (A second “mouse” is wired into the release and is fastened to a board on the floor and used as a foot switch for times when both hands are occupied). To the left of the mouse is a box that controls the output from the Vivitar 283 flash that can just barely be seen at the back of the microscope base (more on that further on).
Below you can see the connections to the camera body. On the side is the release cable and the video-out cable. In the camera’s flash hot shoe is a Wein safe-sync adapter that is used to fire the Vivitar flash unit. This adapter keeps the flash trigger voltage of any flash connected below 6 volts, making it safe to connect to the Canon 10D and other cameras that cannot tolerate higher voltages. (My camera body has a Really Right Stuff “L” bracket attached. It’s the rectangular metal seen around the side. It’s used for regular photography on a tripod. It serves no function for photomicrography).
The bellows used on the stands above both microscopes are an older Vivitar unit, pretty common and inexpensive on eBay. These are manual units that use the “T” mount system. There is a locking thumbscrew below the camera mount that allows the camera to be swiveled a full 360 degrees. For me this is essential to make full use of the camera format, and to compose pictures as I desire. (Above you can see the camera oriented for a “vertical” picture).
My experience has been that it is extremely difficult to focus quickly and accurately using the camera viewfinder. It is not practical at all when working with living subjects. So the camera is set up to be parfocal with the microscope eyepieces. This is accomplished by focusing carefully on an object through the eyepieces, and then moving the camera body up or down above the photo-eyepiece until the image is also in focus. This must be done with great accuracy, and it is hard to move the camera body in small enough increments, even with a good focusing rail between the camera and copy stand. The method I use takes several steps, but has proven very accurate for me.
Using a low power objective, (the lower the magnification, the less the depth-of-focus), I focus on a detailed, high contrast subject. Next I move the camera body up and down using the copy stand movements and a focus rail while looking through the camera viewfinder until I get what appears to be the correct focus. (With patience and test photos this process can be adequate. I’ve taken an additional step, described below, that has worked very well for me).
Next, I take a series of pictures while moving the photo-eyepiece up and down in extremely small increments. This is accomplished on the Meiji scope by loosening the lock on the trinocular tube and rotating the tube slightly. The Nikon head does not have an adjustable trinocular tube so I have made a modification that places the photo-eyepiece in a tube that screws into a collar fastened to the head. The fine pitched threads between this collar and tube allow me to move the photo-eyepiece up or down in extremely small increments by rotating the tube.
Using a low power objective, (the lower the magnification, the less the depth-
Next, I take a series of pictures while moving the photo-
I have fastened index scales in the appropriate places so that the settings can be noted and reproduced. So after achieving the best focus that I can by viewing through the camera viewfinder and moving the camera up and down, I’ll take a series of images, rotating the tube holding the photo-eyepiece one “unit” between each picture. (The goal is to get a series where the sharpest picture is somewhere between the first and last of the sequence). This set of pictures is then taken to the computer where each image in the series is examined at 200% magnification. It is easy to see which setting of the tube provides the best image. Once set, my stands have remained accurately parfocal.
One of the primary subjects of interest to me is living protists and other small animals. It quickly became obvious that I would need to use electronic flash in order to take photomicrographs that would stop the motion of many of these subjects. This resulted in a small odyssey trying a variety of techniques. (Several of these arrangements were quite successful, and will be the subject of a future web article since their applicability is more universal than the technique I use now).
Here, I would briefly like to cut to the end of this “search” and show the way I am set up now. I finally realized that both of my microscopes used a method of “Koehler” illumination where the “light source” that is imaged on the condenser aperture blades (and at the back focal plane of the objective) is not actually the bulb filament, but a “frosted” or “opalized” glass element that is brightly lit by the bulb and collector optics in the base of the microscope. So worrying about the exacting placement of a flash light source at the exact location of the bulb filament was not essential. What was needed was a way to illuminate brightly (with electronic flash) the “opalized” element that became, in effect, the light source for the illumination system. After a little experimentation (and a check on replacement prices!) I took the plunge and cut openings at the back of bulb holders as shown below.
Here, I would briefly like to cut to the end of this “search” and show the way I am set up now. I finally realized that both of my microscopes used a method of “Koehler” illumination where the “light source” that is imaged on the condenser aperture blades (and at the back focal plane of the objective) is not actually the bulb filament, but a “frosted” or “opalized” glass element that is brightly lit by the bulb and collector optics in the base of the microscope. So worrying about the exacting placement of a flash light source at the exact location of the bulb filament was not essential. What was needed was a way to illuminate brightly (with electronic flash) the “opalized” element that became, in effect, the light source for the illumination system. After a little experimentation (and a check on replacement prices!) I took the plunge and cut openings at the back of bulb holders as shown below.
The electronic flash is simply placed at the rear, as pictured below. It seemed ridiculously simple after some of the more involved techniques I tried, but it has worked exceptionally well. I get very even, very bright flash illumination that matches precisely what I see through the eyepieces using the halogen illumination. I had thought that it might be necessary to add some condenser optics in order to “focus” the flash illumination a bit, but that hasn’t been the case. (Although I suspect this could provide an even higher amount of “flash” light on the subject that might prove useful in some unusual situations that require huge amounts of light). The Meiji’s 30-watt bulb proved a bit too hot on the flash with extended use, so a small piece of heat-absorbing glass was placed at the back opening, and heat has ceased being a problem.
I had initially used a Canon 550 EZ flash with the hopes of using TTL flash metering. This quickly proved to be a hassle, since frequent exposure compensation was required as I changed from brightfield to darkfield, or the subject matter changed from the typical white background to a “full frame” shot of a darker subject. This exposure compensation required fiddling with buttons on the flash and/or camera body; both of which were not readily accessible.
Finally, I settled on using the venerable, rugged, Vivitar 283. I already had several of these relatively inexpensive units that had been used for some “high-speed” photography, and knew how easy it was to make a control that would vary the flash output (see right). These units also provide a short, “action-freezing” flash duration when the power level is reduced. The instant exposure feedback obtained via the histogram on the TV monitor quickly convinced me that this “manual” method, with the extremely rapid ability to change power output (in ½ stop increments or less) was the method I preferred.
So this is a very basic description of my working arrangement as we start 2005. I’m pleased with the way things are working now, however, being an inveterate tinkerer, there will likely be additional modifications.