The maximum times in the table are only a guide, and they are only feasible when your hands are very steady, the wind calm, and atmospheric turbulence at a minimum. These relatively short exposures mean that you will have to use fast film, at least ISO 100 and preferably ISO 400, in your Minox.

The addition of any extra optical elements to the Minox’s near-perfect lens can only degrade the razor sharp images we expect from a Minox. Minox pictures taken through the finest binoculars with the camera mounted on a tripod and the shutter fired with a cable release are not likely to be as sharp as what you saw through the binoculars.

But sometimes there is no choice. You’re on a hike in the mountains, you have your Minox on your belt, a pair of binoculars around your neck, and just in case, you slipped the little binocular clamp into your pack. It doesn’t weigh much, and it certainly doesn’t take up much space in your kit, particularly when you consider how much flexibility it gives you.

And suddenly there is a scene that is really beautiful and that requires a telephoto lens. A good tele-Minox photo showing details will surely be better than trying to enlarge a tiny part of the negative. And then the handy binocular clamp proves its worth. Remember, Minox, binoculars, and binocular clamp together probably weigh a lot less than an SLR camera, not to mention the weight of a 300 or 400 mm lens.

My own choice for binoculars to use with the Minox is a pair of 7x42 glasses, possibly because I already have a pair. Other good choices are 6x30, 7x35, and even 8x24. Heavy binoculars with large apertures such as a 7x50 model are, I think, too heavy to carry and also too clumsy. Their large size often leads to strained hand muscles, a sure cause of fuzzy pictures. Center focus binoculars are easier to use than the older kind in which each eyepiece was set individually.

Getting ready

The Minox binocular clamp consists of two separate parts firmly fixed together. The first is a device to hold the camera firmly; the second is a pair of pincers with the opening controlled by a fine adjusting screw. Minox has made several different models of the binocular clamp; the older versions cannot be used with the Minox LX family or AX for two reasons: the new cameras have a 1/4 x 20 bushing for a standard tripod screw for mounting the camera, and the location of the shutter release has been changed.

Fitting older model cameras

All Minox cameras from the A through the BL and C can be used in any binocular clamp, even the newest models intended for the LX and AX. Look into the attachment device and carefully turn the knob at the base of the clamp until the metal toggle is pointing forwards and backwards. Slide the camera into the binocular attachment, seating the camera over the toggle in the opening where the chain plug would fit. Rotate the knob clockwise one quarter turn until the camera locks in place. Screw a short cable release into the socket on the binocular attachment. Make absolutely certain that the Minox is focused on infinity. You will make all needed focus adjustments with the binoculars.

Fitting the LX and AX

You need to have a modern binocular clamp in order to use either of these two cameras. The newer units are easily distinguished by the presence of two cable release sockets, one higher and further forward to fit the shutter release of the earlier cameras and the other lower down and centered, front to back, to mate up with the shutter button of the LX and AX. Slide the camera into the attachment and take care to seat it gently over the toggle. Ingeniously, the toggle on the new attachment has 1/4 x 20 threads on its ends to match the socket on the camera, but it will also lock into the chain plug socket of the older Minoxes! Carefully turn the knob at the base of the binocular adapter until the camera has been securely screwed down into the clamp and the opening on the body for the Minox lens can be seen through the corresponding cut-out on the binocular attachment. Screw a short cable release into the correct (lower) socket on the binocular attachment. Make absolutely certain that the Minox is focused on infinity. You will make all needed focus adjustments with the binoculars.

Now it is time to turn to your binoculars and prepare them for Minox photography. You must gently remove the rubber eyecup in front of the fixed eyepiece – usually the one on the left – of the binoculars. The Minox must be as close as humanly possible to the rear glass element of the binocular eyepiece or it is likely that some of the image will be cut off or vignetted. This is particularly true of "fast" binoculars with large front elements. Indeed, Minox advises that the clamp must actually contact the glass of the binoculars for best results. If you, like me, recognize that aluminum is harder than optical glass, you might want to put some thin tape which can be easily removed on the front of the clamp. Black plastic electrical tape works. You need to cut a hole in the tape for the lens of the camera, of course.

Using the adjusting screw to close the jaws of the pincer part of the clamp attach the Minox to the fixed eyepiece. Three spacers with different cut-out shapes come with the clamp and are attached to it with screws on the back of the jaws. If the clamp as delivered from Minox is a poor fit to the shape of the barrel of the eyepiece you can remove one or two of the spacers on each side of the clamp to secure a good fit. You may find that changing the order of the spacers also helps. The camera clamp must fit on the fixed eyepiece, not the one which you can adjust to compensate for differences between your two eyes. The reason that the camera goes on the fixed eyepiece is that if it is on the variable one you are sure to bump the camera clamp and turn the eyepiece. This will immediately ruin whatever high quality focusing you will later do when taking pictures.

Focusing the binoculars is easy once you have run through a series of simple tests, but you must do the tests and do them with care. Skimping here means that your tele-Minox pictures will likely come out very poorly.

If you wear glasses and you expect to use them when you take tele-Minox pictures, be sure to wear them when you establish the correct point of focus. If you wear glasses and do not plan to use them when you are taking telephoto pictures with the Minox, get out the prescription for your glasses and jot down the values for distance vision. Every one of us has a ‘dominant’ eye. Usually if you are right-handed, the right eye will be dominant, and conversely southpaws usually have dominant left eyes. But this is not always the case, so you must check to see which eye is dominant.

You will always take tele-Minox pictures using your dominant eye to look through the binoculars. My right eye is dominant, so I’ll describe things from that point of view.

When you set out to take tele-Minox pictures two different problems make getting the correct focus quite tricky. The first is that our eyes do tolerate (accommodate) fairly severe focus errors, but the camera won’t be so obliging. This accommodation means that an image which you perceive as sharp might not really be so sharp.

The other difficulty is that what is in focus for your eye may well not be in focus for the Minox camera’s lens. You must set the Minox to infinity and do all your focusing with the binoculars.

To work!

If you plan to take pictures wearing your glasses or contact lenses, you can skip the next few steps. For the rest of us, getting an eye-glass protected eye close enough to the binoculars to really judge focus is too clumsy, and we must find a way to separate out the two effects: focus accommodation and focus error caused by the defects in our eyes. Some of you may not even need glasses!

In practice, however, it is unlikely that the calibrations on the binoculars exactly match those of the optical shop that made your own eyeglasses, or even that your own eyes exactly match the prescription your doctor gave you. Why not? Because your eyes were examined in a darkened room looking at an eye chart only 20 feet (about 6.5 meters) away. And the exam didn’t take place yesterday. Different observing conditions will certainly yield different results, and so you will have to take a set of pictures to find out the exactly correct setting of the adjustable eyepiece.

By the way, and this is shown incorrectly in many books on the Minox, if you are right eyed you will have to hold the binoculars upside down in order to get the adjustable eyepiece to your right eye and not have the camera ram into your forehead or give you a black left eye. This is because, by custom, the right eyepiece is the variable one.

Now it is time to develop the film. When your pictures come back from the lab or out of your darkroom examine the negatives (not the prints!) very carefully through a high quality strong magnifier (I use at least ten power, but if you have only a lower power loupe don’t be overly concerned. The eight power loupe found in the Minox slide cutting device and film magnifier is just fine. Try to avoid using one of the cheap plastic magnifiers sometimes sold by film companies or handed out for advertising. If you are lucky, one frame will be quite sharp with the pictures to either side of it less sharp. Check your records to determine which calibration mark was used, and use that one forever after. If you’re not so lucky you will get two almost sharp shots next to one another, with the frames to either side progressively less sharp. You can simply split the difference between the calibrations for the two almost sharp pictures and use that, or you can see if frame is a little sharper than the other, and set the adjustable eyepiece a little closer to that mark.

Now you are ready to take tele-Minox photos. It takes a lot of work to reach that point, but at least, so long as you don’t change binoculars you won’t have to do it again!

Getting the correct exposure

Two factors enter into estimating the exposure to use with the binocular attachment. The first is the amount of light absorbed in the optical system of the binoculars; this is typically no more than 50% and with modern multi-coated glasses far less, perhaps as little as 10% or 15% which hardly matters, although I usually set my camera’s exposure meter or automatic exposure calibration to one full stop slower than the nominal value for the film I’m using – ISO 50 instead of ISO 100 for Minocolor Pro 100, for example, to compensate for any light losses.

The other factor is the effective aperture of the optical system you are using. This is determined by the aperture of the Minox, 4.3 millimeters (obtained by dividing the Minox lens’s focal length, 15 mm, by its f-number, 3.5). So long as the exit pupil of your binoculars is greater than 4.3 millimeters in diameter, then the lens of the Minox is fully illuminated, and you do not need to worry about f-stop corrections.

But how big is the exit pupil of a pair of binoculars? It is the diameter of the front objective lens in millimeters divided by the magnifying power of the glasses. For 7x35 binoculars, the exit pupil is 5 millimeters across, 35 divided by 7. A 6x30 glass, similarly, has a 5 millimeter exit pupil, and a 7x50 "night glass" one that is a full 7.1 millimeters. But the popular 8x25 compact size has a pupil only 3.1 millimeters across., and a 10x25 high-powered compact unit has an exit pupil only 2.5 mm in diameter.

If the exit pupil of your binoculars is smaller than 4.3 millimeters in diameter you must make an f-stop correction to the exposure time in addition to a light absorption correction. The effective f-number of the binoculars + Minox system is not f/3.5 (15/4.3 millimeters); rather it is given by 15/(exit pupil diameter). For the example of 8x25 compact binoculars the effective aperture is 4.8; this is almost one full stop slower than the Minox lens alone. In order to get correct exposures you will have to subtract another stop from the film speed. This would bring a 100 speed film down to an effective value of only 25, and even in bright light the shutter speeds will likely be too slow to hand hold.

This is why I always advise using very fast film in your camera when you contemplate taking tele-Minox pictures. The photos may be a bit grainy, but they are likely to be much sharper than if you started with only 100-speed film. Minocolor 400 and Minopan 400 are the right choices! Modern color negative films have enormous latitude towards overexposure and very little towards underexposure. They are very forgiving, so if you overestimate the amount of exposure needed through a pair of binoculars, you won’t go wrong.

A final caution: remember that the meter on your Minox sees a wide field of view, that of the unassisted Minox camera itself. The area seen through the binoculars will be far smaller, perhaps only one sixtyfourth of what the meter views (eight power linear magnification results in eight-squared magnification of the area). You may find it best to take your camera off of any automatic setting and make an estimate of the correct exposure and corrections as described earlier. This is particularly true if you are photographing a small dark subject on a light background.

What to expect

The Minox was not designed for interchangeable front elements; the wonderful Minox and Complan lenses were designed to operate alone. Nonetheless, they can be used with binoculars and telescopes to extend their – and your – range of possibilities. But optical instruments not designed to work in combination cannot work as well together as they do separately, no matter how good the lenses are. So you cannot expect tele-Minox photos to be a sharp and as contrasty as ‘unassisted’ Minox pictures. Nor will the photos be as crisp as the view through Minox or Leica binoculars seems to you own eyes; the binoculars were not designed to work with a camera any more than the Minox was intended for use with binoculars.