The Mysterious Door ...

Introduction | A brief history | 60 years | Key Events | Minox is an eye | Seeing with the Minox | Minox Focusing Tips  | The Mysterious Door ... | Design Influences of Leica on Minox | Die MINOX ist Mein Leben | Walter Zapp 1905-2003

© November, 2000 by D. Scott Young, all rights reserved.

Author’s Note : More than one book on Minox cameras, my own included, sadly, have carried on the myth that the access hatch milled into the lens assembly of Model II Minox cameras was put there to allow users to clean the lens. My thanks to Donald Goldberg, the top Minox repair man in America, for sharing with me the truth about this mysterious door, thus giving me the opportunity to correct that mistake. – DSY

No model of Minox 8 x 11 camera has had a more controversial reputation than the ill fated Model II, the first post war camera to emerge from the ruins of Germany after World War II.

Upon his release from a displaced person’s camp under Allied control, inventor Walter Zapp was first set up in a small barn owned by the Rinn & Cloos tobacco concern. With the assistance of some of his Latvian colleagues, who had managed to carry out with them several of the tools and dies needed to begin production of Minox cameras again, they set about creating more of the little marvels. Some parts from the original Riga Minox cameras had been found, and these formed the basis for the first cameras.

The stainless steel body shells were dispensed with in favour of aluminium: strong enough for their purposes, much easier to form into body shells, much less expensive than the casting process required by stainless steel, much, much lighter for the user…and cheap to the point of being free! Many of these new cameras sported aluminium body shells made from the aluminum skins of downed aircraft that were easily found all over Germany at that time.

Being a perfectionist at heart, Herr Zapp wanted his new camera to improve what he considered to be a deficiency of the original Riga Minox: the slight tendency for the negative to become fuzzy at the far outer edges of the photograph, a condition called curvilinear distortion. To this end he hired Arthur Seibert, a lens designer with a good reputation in his field, to produce a new lens for the new camera. Hr. Seibert designed a 5 element lens called the Pentar lens which almost doomed the new company.

The Pentar lens was referred to as a "film plane" lens. The film was physically curved around the rearmost glass element of the lens, in full contact with it. The idea was that by curving the film around the lens, the image would stay sharp even out to the far corners of the negative. It worked: the images produced were noticeably sharper. However, when the film was advanced to the next shot, it was physically dragged over the glass of the lens: the slightest tiny bit of dust or debris in the film chamber would end up being dragged with it, causing horrible scratches on the negatives. These would show as huge lines on the resulting prints, and would be a major disappointment for the Minox photographer, as well as for Zapp and Seibert.

This is where the myth of the mysterious door begins: at some point midway in the production cycle of these new cameras, a milled access port was cut into the lens chamber assembly, covered by a screw on hatch or cap. Not all of these cameras had them, but quite a few did. The rumour began that this hatch was a quick fix for the user to allow them to clean out the lens chamber so that dust and debris would not scratch the negatives.

If you actually look into the film chamber and think about it, you’ll realize that the lens block was hollow, containing the helical focusing assembly which housed the five elements of the lens. This was a sealed assembly while the hatch was on: if the user didn’t open the hatch (and they were not supposed to) then dust and dirt would not get into it. A little more thinking will reveal that the problem with the scratched negatives was from dirt in the actual film chamber itself…and the only part of the lens exposed there was the back of the rearmost lens element, the "film plane" element that the film actually curved around.

So what was the mysterious door for?

The access hatch was intended solely for the use of Minox service technicians as a means of testing the accuracy of the shutter timing mechanism of the camera when sent in to the factory for service. At the time, the shutter blades on these cameras were black, and black does not reflect light very well. In order to determine whether the shutter was opening and closing for the proper amount of time, Minox developed a special periscope tool that could be inserted up into the opening revealed by removing the access hatch. Pointed out towards the lens, this periscope allowed light coming through the open shutter blades to be measured, and from this measurements could easily allow the technician to determine if the shutter timing was proper or not. A unique solution, to a unique problem of the time…typical of Minox thinking!

Later, Minox started producing cameras with the now familiar silver coloured shutter blades, which reflect light very well. This allowed the technicians to use a measuring device that would measure reflected light from the shutter blades, from outside the camera, to determine shutter timing much more easily than before, and eliminating the need for the special hatch.

So, did they ever solve the Pentar negative scratching problem? Indeed!

Arthur Seibert went back to the drawing board and came up with the COMpensating PLANe design (Complan), which was an immediate success. It remained a standard on Minox cameras until after the introduction the Model C1, which then received a new, computer designed lens. The new lens was introduced in 1951 with the introduction of the Model III camera.

The Model III was instantly successful, and hugely popular; with it’s introduction, the first post war Minox, which had been known simply as the "Minox", was now called the Model II. You could say that this might make the Riga Minox the "Model I", but in truth, it has never been officially referred to in that way. Later, with the introduction of the Model B, the III and IIIs models would then become known as Model A cameras in Europe (they are still referred to as III and IIIs in America).

One final bit of mystery: the Complan lens design was so successful that for a number of years afterward, when owners sent their original Model II cameras in to Minox for cleaning and servicing, the factory quietly replaced the Pentar lens assemblies with Complan lenses, often without telling them about it. This immediately improved the quality of the pictures the owners got from them, and was no doubt greatly appreciated. Minox did not change the markings on these modified Model II cameras to Model III, so it is quite possible today to find Model II cameras with Complan lenses…

So, we can now close the door on this mystery.

Last Updated on 18th July 2003

1. The Complan version of the Minox C is rare and much sought after, demanding a premium price. Equally rare are the few Minox Bs with the Minox lens.