Accessories for Macrophotography
Traditionally, in the realm of 35-mm cameras one says macrophotography when the image size on film is 1/2 or more of the actual object size. The 1:1 scale requires the lens to be moved away by an extra focal length from the film plane. Thus, a 50 mm lens will require an extra 50 mm extension to provide life-size image on film. Larger extensions allow for greater-than-life scale ratios.
In addition to special lenses providing extra-long focusing helicoids (like the famous 2.8/35 mm Macro Flektogon), there existed a large variety of macro accessories for the Exakta/Exa system.
This was the least expensive way to get into close-up and macrophotography with an Exakta. The rings were sold in sets, consisting of the rear bayonet ring (attached to the camera, and with a threaded front), a set of (usually three) double-threaded tubuses of various lengths, and then a front bayonet ring with the thread in the back. These can be seen in the picture, from bottom to top.
There were a number of extension ring sets made by Ihagee. The original, pre-war, set had two tubuses (I've never seen one of those), all others — three. Of these, a number of versions were made, differing in the shape of tightening rings, and in their placement along the tube. Two of these are shown here.
There were also aftermarket extension rings made by various manufacturers. One such set (origin unknown) is included in the picture.
The shortest extension possible with such a set was 10 mm (when just the front and rear bayonet rings were used, with no tubes in-between). This would result in magnification of 0.2 with a 50 mm lens. The tubes provided an extra 5, 15, and 30 mm, or any combination of these, so that the maximum extension possible was 60 mm, resulting in magnification of 1.2 (slightly more than life size).
For some close-up applications the 0.2 magnification would be too much. Therefore there was an extra accessory available (usually sold separately): a double-bayonet ring, with just 5 mm of extension, and magnifications from 0.1 (more if the lens itself was set to less than infinity).
A semi-automatic or automatic lens used on extension rings or bellows no longer couples with the shutter release on the camera. This is why Ihagee offered a contraption called Auslösebrücke, or release extension.
This is a metal rod with adjustable fixtures, passing the pressure exerted on the shutter release on the lens to one on the camera body.
Two versions were made:
Greater and continuously adjustable extensions were possible with macro bellows.
Ihagee made one model of these (in a number of cosmetic variants), providing extension from 35 to 125 mm. The unit had bayonet mounts on both ends, so it would work with any Exakta-compatible lenses.
It is shown here, mounted on a Varex IIa (*5.1.1.e), with a sunken-mount 2.8/50 Tessar and magnifying finder with loupe. These will be separately described below.
To see how I am using these bellows on a digital camera, click here.
A number of other manufacturers offered macro bellows for Exakta. Some were more flexible or longer (e.g., Novoflex), some — just less expensive.
The Japanese Kopil bellows were in the latter group, but not just that: they were also less heavy, and the rod was collapsible, making the unit more transportable.
Shown here are the Kopil bellows, mounted on a Varex IIb (*6.0.e) with a Westrocolor 1.9/50 lens. A double cable release (made by Pentacon?) is used to retain aperture coupling.
The setup also uses the magnifying finder, but this time with a 2.0/50 manual Biotar lens serving as a loupe.
(The Kopil bellows are easy to find even now: I bought these on eBay for just $5.)
The minimum lens extension of 35 mm available with the Ihagee bellows would limit the maximum focusing distance or minimum magnification. For a regular 50 mm lens only magnifications above 0.7 would be possible, necessitating switching to and from extension rings in many typical applications.
This is why sunken mount lenses were introduced, with the optics moved way back (more exactly: 35 mm) in the barrel, well behind the lens bayonet mount. This allowed using bellows to focus the lens all the way to infinity. Obviously, such lenses did not need a focusing mechanism of their own.
The best known example of a bellows lens is the 2.8/50 Zeiss Tessar (shown). It can be also seen in the first picture of the Macro Bellows section above.
Finder magnifier unit and loupe
To help in critical focusing in macro applications, a special interchangeable finder was made.
It would accept any finder screen (of these fitting prism finders), and provide a regular Exakta lens bayonet on the top. A short-to normal (35-50 mm) lens mounted there could serve as a high-quality magnifier.
Ihagee made two versions of the magnifying finder, 1952 and 1957. The older one (shown at the right in the picture) has a distinctive, crackled finish, and larger external bayonet dimension, and the red dot for lens alignment faces the camera front.
(Click at the picture to see the full-screen version, where the differences will become instantly obvious.)
I also have the later version without any markings on the chromed metal plate.
Lenses were quite expensive and not every user had one to spare, therefore a separate loupe magnifier was made to work with the unit.
As in the previous case, two versions of this loupe were made. The older one (at the right) was more squat and had the eyepiece of 23 mm in diameter, compared to 18 mm in the newer version (where it was also protruding a bit).
Adding any extension to the lens-film distance greatly reduces the brightness of the image — both on film and in the finder. For example, when using all extension rings to get a 1:1 magnification, the image gets four times less light (i.e., two F-stops). Using the macro bellows at full extension makes virtually impossible to see anything in the finder.
This is why Ihagee was offering a number of screens intended mostly for macro- and micro-photography. Instead of a matte groundglass side, these screens had a clear glass surface. The image brightness was suddenly an order of magnitude higher. Three such screens were offered: clear glass with a crosshair (shown), clear glass with a grid, and a groundglass with clear center which had a crosshair inside. (According to a 1969 catalog, similar screens were available as thick blocks, suitable for waist-level finders.)
Nothing comes without a price. Without a matte surface, the photographer was not viewing the image on the groundglass, but an aerial image near it. If the lens was not in focus for a given object, that image would be in front of, or behind the flat glass surface, but the human eye would still accommodate and see it sharp. Therefore using the finder image to focus was impossible, or almost so.
The crosshair or grid etched in the glass was provided not only as a guidance. With some training it could be used as a help in focusing through the finder, in spite of what was said above. Because the etching was in the plane in which the properly-focused image would be created, you could learn trying to set the focus so that both the image and the etching were seen sharp at the same time. Or so people say. I've never learned how to do it dependably, but maybe I was not trying hard enough.
Exakta Accessory Catalog
Some other items related to macrophotography (lens inversion ring, ring flash, more) are listed and described in my write-up of the 1969 Exakta accessory catalog.
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|Posted 2004/01/20; last updated 2005/01/29||Copyright © 2004-2005 by J. Andrzej Wrotniak|