Tengor Tango - Part 2

[Author’s Note: I credit the historical references to the Box-Tengor series of cameras in this article to the research of Daniel Sanchez Torres who has documented extensively on the production history of the series here. The Box-Tengor series has gone through a number of variations and modifications over its 30+ years production which, combined with relatively widespread availability and low prices, make it a good choice for a hobbyist camera collector.]

In Part 1 of this two-part series, I discussed my early Goerz Box-Tengor model 760 6.5x11 format camera along with some promising test shots I took after making small modifications to support using 120 roll film instead of the native 116 roll film the camera was designed to use. After a couple of outings and with some more practical experience using this camera, I would like to add a couple of additional points.

First, in the original discussion, I mentioned that the shutter had a B (bulb) setting. This was incorrect. The shutter has an actual T (time) setting where, when activated by the sliding lever, once the shutter is tripped, it will stay open of its own accord after releasing the shutter lever. To close the shutter, the shutter lever has to be moved back to the original position (pushing the T lever back in won’t close the shutter). Also note that, for the Instantaneous shutter setting, the shutter release works in both directions (i.e., there is no return spring to move the lever back to its original position). AFAIK, this behavior is unique to the early models of the Box-Tengor that don’t have the “silver spoon” shutter cap that was added to support the automatic return shutter lever on later models.

Second, regarding the lack of tripod sockets, I mentioned that a cell phone clamp from a selfie stick should work fine. However, in practice, I found my cell phone clamp didn’t quite give sufficient grip or stability. While the spring tension on the clamp was more than sufficient, in fact a little too strong as it tended to distort the thin sheet metal on the sides of the box, the surface area of the clamp was too small to hold the camera rock steady. So, I went to my garage and came up with the following tripod mount design specifically for metal-bodied box cameras. This mount consists of two steel L-brackets with two rare-earth neodymium magnets on the bottom arm of each bracket. The magnets are wrapped with electrical tape to keep from marring the camera surface and to make it a little easier to remove the camera from the bracket. The magnets are more than strong enough to hold the camera in either vertical or horizontal position and provide the necessary rigidity to make long exposures. I should note, however, that to make long exposures, I used a black card to cover the lens before I manually tripped the shutter and then again to cover the lens before I closed the shutter to avoid shaking the camera since there is no cable release socket on this older model.

Now let’s move on to the second Box-Tengor in my collection: the Zeiss-Ikon 54/2 model circa 1931-1938.

The 54/2 Box-Tengor derived from the original Goerz model 756 6x9 format (120 roll film) Box-Tengor that Zeiss acquired after the merger of Goerz and other German camera companies into Zeiss-Ikon in 1926. Initially, Zeiss retained the 756 model number, added their stamp to the body covering, and replaced the original laterally-positioned metal handle with a leather strap. Otherwise, the camera was identical to the Goerz model. In 1929, the 756 model number would change to the new Zeiss numbering scheme as the 54/2 along with a few other changes: the viewfinder ports moved to the top corners of the faceplate, the film wind crank moved from the bottom to the top, and the “silver spoon” shutter cap was added to facilitate the automatic return of the shutter lever to its home position (i.e., the shutter was no longer double-action as in the earlier models) which also supported the addition of a cable release socket.

Around 1931, the 54/2 model was updated with a new hexagonal faceplate supporting a zone-focus lever above the lens that allowed for one of three focus zones to be selected: 1-2 meters, 2-8 meters, and 8-infinity meters. Each of the two close focusing zones has its own diopter lens that is positioned behind the taking lens when the selector lever is moved. The previous aperture-selecting sliding lever was replaced by a circular wheel with Waterhouse stops controlled by a lever below the lens. Finally, a shutter lock lever was added to prevent inadvertent firing of the shutter and/or to hold the shutter open for extended periods (when using the “T” setting for example). This is the variant that I own and, for all practical purposes, contains the essential features that are only slightly augmented in the later 6x9 models 55/2 and 56/2. Note that, unlike the Goerz model, when using the “T” shutter setting, the shutter does not stay open after it is tripped unless you manually hold it open or lock it open via the shutter lock lever or a locking cable release. In this sense, it is actually a “B” (bulb) setting.

My 54/2 was in overall good condition, bruised but not battered, when I purchased it at the antique store. Cleaning was easy as there are only two screws that hold the faceplate on and, once removed, there is full access to the taking and viewing lenses, diopter lenses, viewfinder mirrors and lenses, and the shutter mechanism for cleaning. The only tricky part is reinstalling the faceplate because it’s a tight fit and you have to align the zone focus and aperture levers with their openings.

Once cleaned, I was anxious to shoot my first roll and see the results. My expectations were high based on previous experience with my Goerz 760 model. However, once the negatives were dry, I could see that something was not right. The long arm of Murphy’s Law had grabbed hold of me. Specifically, there were two distinct issues with the images:

1. The in-focus areas of the images were not as I expected. In fact, they reminded me of photos I had seen taken with cheap plastic cameras. I wasn’t expecting the full frame to be sharp since I had used the maximum aperture of f11 but I did expect the central portion of the image to be reasonably sharp. Instead, the upper portions of the image tended to be sharpest and I noticed some vignetting at the bottom corners of the image but none at the top. This prompted me to scrutinize the camera more carefully and, as a result, I discovered that the top portion of the faceplate directly above the taking lens, to which the taking lens is attached, was pushed in enough to cause the taking lens to point up slightly and not be in vertical alignment with the focal plane. This, in turn, would cause the image circle to be shifted down on the image plane which could cause vignetting at the bottom of the image (or at the top of the focal plane since the image is projected upside-down at the focal plane). The distortion in the faceplate did not seem to be caused by an impact because there was no sign of surface damage. Instead, I think the slight depression was due to squeezing of the camera by users trying to adjust the zone focus lever since it is quite tight. The faceplate sheet metal is sufficiently thin that it can be distorted by hand pressure without too much effort. In fact, because of this, I was able to straighten it back using my hands.
    
    
   
2. At the “8m-infinity” zone focus setting, the entire image was substantially soft, both near and far subjects. In fact, images shot at the middle zone (2-8 meters) were sharper at all distances. Fixing the previous issue did not affect this. Based on anecdotal evidence published on the web from other users of this model, I tend to believe this defect originated at the factory. My semi-educated guess is that the taking lens is too close to the focal plane and that the mid-range diopter can compensate for this somewhat. If that is true, then I suspect the closest focusing distance is affected as well but I would need to test that hypothesis.
   

Below is an example of the first issue. This image was shot on the middle focus zone (2-8 meters) at f11. In the full-res image, the foreground is pretty fuzzy until you get closer to the trees. Also note the vignetting at the bottom corners.

And here’s an image to show the softness when using the “8m-infinity” zone focus setting. In this photo, the farmhouse is approximately 40 meters away. The full-size photo shows the image taken using the “2-8m” zone setting (the sharpest result) and then magnified views showing both the 2-8m zone and 8m-infinity zone results. All photos were taken on a tripod at the maximum aperture of f11.

Farmhouse - 2-8m focus zone, f11

2-8 meter zone left, 8-infinity zone right

In summary, even with the infinity focus zone issue, this camera is a pleasure to use and I can get satisfactory results using only two of the zone focus settings. I still need to figure out the exact distances covered by the lower two ranges but that’s for another day. In the meantime, I’ve included a couple of sample images below. Thanks for looking!

Gary

Fence Post

Crooked Path

cover and pg 1 of 1951 Zeiss sales booklet (Frontar lens f/9)

(but that shape on the title page looks suspiciously like the map of EAST Germany?)

That is a nice lens. Goez?

Yes, and as far as I know, all Box-Tengors are fitted with the Goerz Frontar achromat.