The single-lens reflex camera EXAKTA Varex opens also – similarly to close-ups – the large field of Photomicrography, by simple and inexpensive accessories. The reflex screen image serves for focusing and observing the microscopic picture. You observe it until you press the shutter release button.
The two Microscope Attachments connect the EXAKTA Varex to any microscope. The camera can be adapted with one of the two attachments to the ocular tube of the microscope which has the standard outside diameter of about 25 mm. Microphotographs are taken with the optical system of the microscope and not with the camera lens.
Microscope Attachment Type 1
The camera is fixed to the top part of the attachment: The bayonet ring is put into the camera-bayonet in the same way as a lens. To attach the combination of camera and attachment to the microscope, remove first the ocular from the microscope tube. Camera and attachment tilted up are put on the tube, the ocular is replaced and, by a slight turn of the clamping screw, the microscope attachment is fastened to the microscope tube. Then the camera is tilted up and the microscope attachment bolted up. By means of the hinged clamp the camera can always be tilted to the side, when photographic work is being suspended for exchanging oculars or when subject observation should continue.
Microscope Attachment Type 2
Top and bottom parts of this attachment can be separated by loosening the quick-change mount: The indented screw is slightly screwed out and the top part of the microscope attachment lifted out of the mount. The top part is attachable by its bayonet ring to the camera as usual. Then, after removing the ocular of the microscope, push the bottom part on the notch-ring by turning it to the left, whereby the grip-border must be held fast. The top part of the micro attachment with the camera is put into the quick-change-mount: First place the cone under the two latches, then the opposite side slides into position. Tight the set screw, and make the top part in the mount safe to operate.
The top part cone of type 2 of our microscope attachment is also adaptable to all microscopes with tubes of 25 mm. diameter. On these microscopes the tube is removable and the EXAKTA Varex together with the top part of the micro attachment is placed into the switch mount of the tube support of the microscope. It is possible to take so-called “Lupen” Pictures – Macro photographs – with the microscope objective alone. The Microtars are especially qualified for this purpose. We regret that it is impossible to give here technical instructions for taking photomicrographs. This field is so large that it will be of no use picking out a few points only. We rather recommend to consult one of the many books about this subject.
Special focusing glasses
The possibility of instantaneously interchanging the focusing glasses of the EXAKTA Varex is of great advantage for taking micro- and “Lupen” (macro) pictures. You can use, instead of the regular ground glass, the special glasses described below. Although it is desirable to compose the image on a ground glass, the sharpness must be determined through the clear centre spot by focusing into the air. In taking “Lupen” photos a fully clear glass proves to be indispensable. The ground glass of the reflex finder hood is on the under part of the large magnifying glass, which may be removed from the framework by loosening two holding screws and replaced by the desired type of glass. It is, however, recommended to purchase an additional complete reflex finder hood with the desired glass for the sake of greater convenience, particularly as the price is not high. With the Penta Prism, however, the ground glass can be changed and consequently special glasses alone are available for it.
The following special glasses are offered:
- Reflex Finder hood with ground glass and clear center spot of 3 or 10 mm. (both with hairline cross in the clear spot)
- Reflex Finder hood with focusing glass completely clear and hairline cross.
- Ground glasses for Penta Prism with clear center spot of 3 or 10 mm. (both with hairline cross in the clear center spot)
- completely clear glasses with hairline cross.
The focusing systems with clear center spot or clear overall are also practical for endoscopic pictures in medical photography. The hairline cross avoid, at all times, the unwanted continuation accommodation by the eye. In Photomicrography correct focusing is attained when both hairline cross and image appear to be simultaneously sharp. When moving the eye over the clear spot to and fro, hairline cross and image must not shift each against the other, if correctly focused. The same should happen when taking “Lupen” pictures. Other special types of focusing glasses could be supplied according to specifications (e.g. with etched cross lines, cm. or mm. graduations, etc.)
The supplementary magnifying lens in the Finder hood of the Exakta Varex does not always meet the great optical requirements of critical focusing in close-up and micro-work. Therefore, the “Lens Magnifier” was designed for the specialised fields of Macrophotography and Photomicrography. It can be inserted into the Exakta Varex instead of the Finder hood or Penta Prism, and makes possible to focus and examine the reflected image with one of the highly corrected EXAKTA Varex normal and special lenses. The lens is set in the bayonet mounts of the Lens Magnifier. Focused at infinity, it shows a magnified and evenly sharp reflected image without distortion or aberration.
All normal and special ground or clear focusing glasses may be used in the Lens Magnifier. With a partially or completely clear screen, the image is easily and quickly discernable. The normal or long-focus lenses when used as critical magnifiers permit to examine the whole area of the reflected image, whereas with a 40 mm. picture taking lens the range of vision is somewhat limited so that you will see the center part of the image only.
The Lens Magnifier is all the more practical as the normal lens of the EXAKTA Varex is not used for taking Photomicrographs, thus being free for serving as magnifier. Additional magnifications can be obtained, when holding a small pocket telescope as supplementary focusing help over the Lens Magnifier (e.g. the Tellup giving a 2.5 times magnification).
The total magnification results from multiplying the lens magnification with that of the pocket telescope. The modern lenses the mounts of which offer the comforts of the pre-set diaphragm and the automatic diaphragm presetting device and additionally operate as a natural light trap, too, have, however, when used as a magnifier, a distance somewhat too large between front lens and eye, so that you can no more see the full ground-glass image. For the Lens Magnifier, therefore, an additional magnifying glass was made, effecting a magnification of about 4.5 times (thus total magnification with the magnifying ground glass about 5 times). So you can very well control and accurately focus the total ground glass image owing to the good optical performance of the additional magnifier.
This magnifying glass is mounted in the same way as a lens of the EXAKTA Varex and inserted so, too, in the bayonet of the lens magnifier.
Close-up and micro exposures with the EXAKTA Varex are not only obtainable with the accessories described in this booklet. For achieving utmost economy in this field, as well as in other spheres of photography, the “Vielzweck”-Multi-Combination for the EXAKTA Varex has been designed. Please ask for information, also regarding this equipment, the versatility of which you will find most welcome. We shall be glad to send you a detailed brochure. Here just a short reference to the individual groups of the “Vielzweck”: For close-up and magnifier work there is the Bellows Attachment (Fig. 9). Reproductions are conveniently carried out with the help of the Copying Stand, which, by the way, also serves as a sturdy table tripod for other purposes. The Bellows Attachment and Copying Stand combined are used for photomicrography. Duplicates of small transparencies, on an optical basis, are made with the Transparency Copy Equipment. For medical photography, especially for photographing cavities of the body, the “Kolpofot” has been especially constructed. It works in connection with an electronic flash unit.