Microscope photography is very beneficial. For one thing, you may be able to recover or to create hard evidence if you ever make a breakthrough discovery. It does not only take pictures in stunning detail but also shows amazing evidence of microscopic proportions. The use of digital cameras for photo microscopy provides an exciting opportunity for capturing and displaying a world normally hidden from the naked eye. Two important advantages that digital technology affords you are instant feedback, and the ability to take many pictures inexpensively. This is important because of the difficulties associated with getting good images from objects measured in millimeters. Taking a picture from a microscope is a tricky task. Taking pictures through a microscope creates a special set of problems for the photographer. Essential things that must be considered are the type of equipment to be used, getting the equipment to work together, lighting, focusing, shutter release and a myriad of others.
The first thing to consider though is compatibility of the equipment you plan to use. The camera and microscope must work together to create the image. To work together the camera and microscope must be attached. The first question to ask is where do you plan to attach the camera to the scope. Some microscopes are designed to have cameras attached to them. This is called a C-mount. This type of mount is able to attach directly to a 35mm camera body. The problem is most consumer level digital cameras do not have a 35mm lens mount. A different possible point of attachment is to the eyepiece of the microscope. This is especially feasible on the dissecting scope, which typically has larger ocular openings than a compound scope.
This method allows the use of cameras that couldn’t otherwise be attached to a microscope, as well as the use of microscopes that don’t allow conventional camera attachment (which are usually less expensive and more common). Once you have attached the camera to the scope and have a working system other secondary problems will become apparent. These include what type and system of lighting that you will use, how to release the shutter of the camera to reduce camera shake, and the methods used to control focus, exposure and color of the image. The goal here is to describe some of the important features the camera and microscope should have to overcome the problems associated with taking digital pictures through the eyepiece of a microscope, and then explain the methods used as an example.
Important feature the camera needs to have is a tripod socket. This will be the main point of attachment for the camera. An adapter must be purchased or constructed that has a tripod mount for the camera at one end, and some method of attaching to the microscope on the other. Stability is the most important consideration for this adapter. The point of attachment on the microscope also needs to allow the “head” of the microscope to move up and down to focus. There must also be some method for attaching the lens of the camera to the eyepiece of the microscope. Again an adapter must be purchased or constructed. Three criteria are important. First, the method must be safe for both the optics of the camera and the microscope. If there is any possibility of scratching these, the adapter must prevent this unhappy event. Second, the method must be stable to prevent camera shake.
Third, the adapter should block extraneous light from entering the camera from the gap between the lens and eyepiece. The camera lens diameter needs to be roughly equal to or less than the diameter of the microscope eyepiece opening. This is important because although the camera has a circular lens, it takes a picture that is rectangular. This rectangle fits inside the diameter of the camera lens and also must fit inside the diameter of the microscope eyepiece. If the rectangle doesn’t fit you will get a picture of your subject framed by a circle with black edges filling in the rectangle. This problem is called vignetting. To avoid it the diameters must be close, a little bit of fudging can occur if the camera has zoom capabilities. Zooming the camera in all the way uses a smaller portion of the total lens area, effectively shrinking the “real” area of the rectangle.
Another important thing to consider about the lens of the camera is whether the zoom is internal or external. If when the camera zoom is used you can see it “telescope” in and out, it has an external zoom. For photo microscopy this type of zoom will be more difficult to attach to the scope and also less versatile when used. Because of this it is recommended to get a camera with an internal zoom (one that cannot be seen telescoping in and out when in use). Another consideration is the amount of manual control that the camera has. The more control you have over things like aperture, shutter speed, white balance, focus, and flash the better the quality of the images and the more versatile the setup will be. Systems such as exposure control on the camera that are not through the lens will be fooled and must be shut off or compensated for. The colors will often be off using the camera’s automatic system when taking pictures through the scope. A manual white balance is invaluable.
To do a white balance the camera measures a white card, through the microscope, in the provided light. It also helps to be able to lock the auto focus of the camera and focus with the microscope. The ability to manually turn off the flash is also helpful, especially if the camera is automatically determining the exposure. Most of the light from the flash will not reach the target and you will end up with an underexposed image. With regards to the microscope, considerations are a little more general. The most important consideration, for this method, is the size of the eyepieces. As mentioned above the eyepiece diameter must be around the same size as the camera lens. The ability to change the magnification on the microscope is very valuable for different sized subjects and increases the versatility of the setup. Lastly optical quality of the scope is very important for photography but unfortunately seems to be directly proportional to cost. When taking considerations about the lighting, illumination commonly used includes natural, halogen, incandescent and a misguided attempt at fluorescent. When taking a photograph of a wet specimen or in water, it is important to get enough light for proper exposure, but at the same time having it be soft enough so as not to create bright spots of reflection from the source. Finally, key to lighting is to experiment and figure out what works best for your conditions.
