THE EYE IS A MINOX

Peter Zimmerman email: peterz@erols.com

Minox pictures in contrast, have a familiar, almost cozy, look about them. When a Minoxer focuses correctly, the eye of the camera renders the subject at least as sharply as does the human eye. If a 35 mm camera with a normal lens (40 to 50 mm focal length) had been set at the same f/3.5 aperture as the Minox, foreground and background would be unsharp. Under a microscope they are unsharp on a Minox picture too, but the degree of unsharpness seems to be something to which we are accustomed; it is not as abstract as the rendition on a larger format negative appears.

Take a picture with a Minox, a picture with a distinct foreground subject and a background with a lot of detail. Enlarge the picture to about 8x10 inches, a size where details are clear even if the picture is held at arm’s length; and then take the enlargement and go stand exactly where the camera was when you took the picture. Let your eye focus on the main subject and then gradually slide the print into view; move it forward and back until the foreground subject appears to be the same size in reality and on the print. The sharpness of the background, as the eye sees it in reality, is almost identical to the sharpness on the print.

Minox enlargements give a familiar view of the world. Why should that be?

The optical system of the human eye is very, very similar to that of the Minox. When my eyes were examined recently, I asked the ophthalmologist what was the focal length, the ‘refractive strength’ of the eye. ‘On average,’ he said, ‘about 63 diopters.’ In camera terms, that is 1/63 of a meter or 15.9 mm. In bright lighting, the iris of your eye closes down to about 3 mm; in dimmer conditions the pupil enlarges to about 5 mm. Under common circumstances the human eye is an f/3.5 to f/5.6 optical system operating at a focal length only a few per cent different than the 15 mm which has been the Minox standard since 1938. The eye is a Minox; no wonder the depth of field we see and the depth of field recorded on a Minox negative are so very similar.

The similarity between your eye and the eye of the Minox is probably a coincidence. Walter Zapp selected a 15 mm focal length because it was the ‘normal’ lens for an 8x11 mm negative, since it gives about the same field of view as a 50 mm lens on a 35 mm camera; an f/3.5 lens was probably a compromise combining good depth of field, reasonable exposure times in an era when films were much slower and grainier than they are today, and superb lens performance all at a price commensurate with other fine cameras and luxury accessories. But it is a coincidence which has real utility for the Minox user. It means that, when the camera is properly focused, what the human eye sees is what the camera will record. The photo will mirror reality as the photographer experienced it, without the abstraction of total sharpness everywhere or a single isolated plane of sharpness and a great volume where objects can barely be identified.

An expert in optics will argue that when an image is enlarged the same number of times -- and Minox negatives must be enlarged more than 35 mm negatives -- the depth of field depends only on the aperture and not the focal length. That’s true as far as it goes. But depth of field is also arbitrary and depends on just how far out of true focus the lensmaker is willing to say the image is still ‘sharp’. Because its negatives are so tiny, the Minox designers chose a ‘circle of confusion’ of 1/60th of a millimeter, while professional 35 mm lenses are usually computed using 1/30th of a millimeter, twice as big. Some amateur cameras have even had depth of field markings based on 1/20th of a millimeter!

The user of a telephoto lens on a 35 mm camera wants to isolate a subject; the large format photographer wants an ultra-sharp final print. The Minoxer knows that an enlargement from the tiny negative will produce a photograph which places the viewer’s eye right where the camera had been. It is a comfortable feeling. But it does depend on one thing: making sure the camera is focused correctly on the main subject. Depth of field is never a substitute for focusing correctly in the first place.

Minox Focusing Tips

Every Minox lens, from the first production Riga models to today’s TLX and EC, has enormous depth of field. Objects both near and far can be in acceptable focus at the same time, on the same picture, to a degree uncommon in photography with larger cameras. Indeed, since the early production runs of the Minox III, most Minox cameras have had a small dot between the six foot mark and the infinity mark, a ‘snapshot’ setting at 12 feet. Twelve feet is the ‘hyperfocal distance’ for the Minox lens; everything is in acceptable focus from half the hyperfocal distance all the way to infinity. The hyperfocal distance depends, of course, on just how unsharp the lensmaker will still call ‘sharp’. On the Minox a point object can only blur out to 1/60th of a millimeter because the negatives are so small; larger cameras allow greater blur, up to 1/20th of a millimeter on some inexpensive 35 mm cameras.

Somehow the idea grew up that if you just set the camera to the dot, all of your pictures would be sharp. While most pictures of people and buildings taken with the snapshot setting will be acceptably sharp in a 3x5" print, a photographer who routinely uses the snapshot setting has cheated himself out of most of the performance of the wonderfully sharp optical system provided in every Minox.

The Minox f/3.5 lens probably has the highest resolution, well over 200 line-pairs per millimeter, of any lens on the commercial market. But it will only deliver that stunning performance when it is focused sharply on the subject. The great depth of field of the camera means that the Minoxer need not guess to the very inch how far away the subject is, but laziness in focusing will result in pictures nowhere near as good as they can be, and should be. Estimating distances sounds difficult, but it is not; you carry a number of measuring rods around with you all the time, and need only remember a few simple numbers in order to obtain far better pictures than either the snapshot setting or wild guessing will deliver. Here is how it works for me:

I estimate paces. It’s easy to know whether I am one stride, two, three, or four, from my subjects. My pace is just a bit longer than three feet, which matches well enough to the marked focus points on the Minox. If the closest object which must appear sharp is six or more paces away, and the background is important, I set the camera to infinity. If the closest object I care about is closer than six paces away, and the background is not critical, then I set the camera at the subject’s distance, and let the depth of field extend the sharp zone forward and back. If the background must still be sharp, split the difference: focus on a point just a little farther away than the distance to the subject. There may be more depth of field behind the subject than in front of it, but backgrounds which are just barely blurred in a print are often disturbing.

I am 5'10" tall. By actual measurement, when I bend my head down to take a picture at my feet, the front face of a Minox held to my eye is five feet off the ground. Do I want a picture of flowers, leaves or plants anywhere near my feet? I set the Minox to a distance just a little shorter than the 6' mark on the focusing dial. Not much shorter; four feet away is already fairly close to the 6' mark.

Most American dining tables are about 30 inches wide. If I want a party picture of my companions across the table, I set the Minox to four feet. That allows for the fact that I’m a few inches back from the edge of the table, and my friend is probably also sitting back a bit. Is he or she leaning forward? No problem; set the focus to a point a little closer than three feet. If their seats are to one side or the other of me, I add a couple of feet. Is dinner over, and have the guests pushed back from the table a bit? Use six feet or just a little more. For longer or bigger tables, decide whether your subject is one, two, or three steps away from you.

The measuring chain was designed to help the photographer exploit the extremely close focusing capabilities of the camera, but it is not always convenient to use -- sometimes it’s even too short. And in the open there is always the probability that your position will change between measuring the distance and taking the picture; you may bend backwards, or you may have trouble following a flower being blown by the wind, for example. My secondary measuring chain is my left arm (I am right handed). Stretched out full length so that the tip of my middle finger is in the center of a Minox frame, the distance from finger tip to Minox lens is 26", just a little longer than the 2 foot focusing mark -- almost not enough difference to matter. You could use your right arm instead of your left, but I hold the Minox in my right hand and want to be able to see what I am doing through the viewfinder.

From wrist to finger tip, my hand is 7.5", a little closer than the closest focus point of a Minox. I can just about use my hand to replace the chain. Spreading my fingers wide, it’s just 8.5" from little finger tip to thumb tip. I don’t try to remember the exact lengths of my arm, hand, and wrist, just that they are pretty close to the two foot focus point and the closest distance at which the Minox can focus.

Photographic sharpness does not fall off immediately, and the depth of field mark on the Minox is not an absolute. A subject at a distance well inside the outer ends of the mark will surely be rendered sharper than one at either end of the marked zone of sharpness. The depth of field of a Minox is calculated by assuming that for normal enlargements a blurred circle on the film 1/60 of a millimeter in diameter will still appear sharp to the eye. It will, but if the region of blur, called the circle of confusion, is 1/120 of a millimeter, then the subject will appear even sharper. For critical work, when you hope to enlarge a Minox picture to 8x10" or 11x14", divide the depth of field mark in half and only use the center section to indicate where the picture will be really sharp. If the camera is focused at 12', then objects between 10' and 16' will be a lot sharper than those at 6' and infinity, the endpoints of the depth of field scale, will be.

Carry the Minox set for snapshooting if you like, since that can often let you point and shoot with acceptable results, but always try to follow up with a correctly focused picture. An alternative which I and others find useful is to have the baseline setting at six feet. Then everything from about four to twelve feet will be acceptably sharp, and that distance range is very convenient for candid shots on the street.

But focus as accurately as you can every time; the results compared to using any ‘snapshot’ setting are astounding.

Figure caption 1: The camera was carefully set to focus on the closest point of the tree, with the background allowed to be as sharp as depth of field would allow. Under a magnifier one can easily make out the mullions in the windows and the mortar between the bricks. [Kodak Technical Pan film slit with a Minox slitter and spooled into a reused Minox cassette. Developed in Rodinal+sulfite.]

Figure caption 2: The bush seemed to be the most important point in this photo, and so the point of focus was put there (I paced off 5 steps). Because the wooded area is quite far away, it is not critically sharp, even though infinity is within the ‘depth of field’ of the Minox lens. [Ilford Delta Pro 100 film slit with a Minox slitter and spooled into a reused Minox cassette. Developed in Ilfosol.]

Figure caption 3: A 44x enlargement of the area surrounding the bush. This is an enlargement equivalent to a 14x19" picture from a 35 mm negative.

Figure caption 4: President Clinton during the 1992 campaign. With the crowds and the jostling it just wasn’t possible to focus and refocus. I kept the Minox LX set to six feet and fired away, sometimes with the Minox electronic flash and sometimes in available light. The depth of field made most of my pictures acceptably sharp. A good compromise.

Figure caption 5: These three boys are men now; the picture was on my very first roll on Minox film. Because the Minox works very much like your eye, pictures such as this one seem natural and easy to take. Minox Plus-X film.

Figure caption 6: An enlargement of the house behind the tree. The details are not critically sharp; they have just about the same amount of fuzziness about them that your eye shows when you are concentrating on the tree.

Note on films: Kodak Technical Pan film probably has the finest grain of any film available, but Minopan 25 developed in a fine grain developer would give similar results at 8x10". Ilford’s Delta Pro 100 has slightly finer grain than Minopan 100, but it’s harder to print than the Minox film; these pictures were part of an extensive film test.