Tewe Polyfocus viewfinder

The Tewe Polyfocus viewfinder is arguably one of the best zoom viewfinders ever made. Sure, it's not perfect, principally because the edges of the frame are a bit fuzzy, and are represented by, well, the edge of the frame, rather than a bright-line. Also, it's not what you might call a 'pure' zoom: the image area gets smaller as the image is magnified, so that the apparent frame size at 200mm is about 60% (linear, 36% area) of the apparent frame size at 35mm. Even so, that's a vast improvement over a straight masking finder, where the 200mm mask would be about 15% linear, under 0.025 area, as compared with 35mm. Oh: and eye relief at wide-angle settings is tight: you don't want to be wearing glasses.

As well as offering focal lengths from 35mm to 200mm, with different indices for infinity and close up, it has parallax correction; it's beautifully made; and it's easy to use. Just turn the milled ring. And, if need be, move the parallax lever.

tewe three-quarter

 

Tewe Polyfocus

Superb German engineering. Admittedly, it should have been good at the price. The first reference to it that I've found is in the British Journal of Photography Almanac for 1953 (printed, therefore, in 1952), on page 238. The price was £15 plus £6:10:0d purchase tax, £21:10:0d in total. As prices (according to the UK Retail Price Index) have gone up by a factor of rather over 20 since then, this equates in 2010 terms to over £300 before tax plus more than £130 tax for a total price well north of £430.

The Tewe is near enough 40.5mm (1.6 inches) front-to-back at the 35mm setting, 48.5mm (1.94 inches) at the 200mm setting (see illustrations below). The barrel is 29.5mm (1.15 inches) in diameter at the widest point, the knurled ring. Maximum height at infinity is 41.2mm (1.62 inches): at the closest parallax-adjusted distance, the rear is about 1.3mm (0.05 inch) higher. It weighs about 85g (call it 3 ounces).  The finish is in the highest possible quality of satin chrome, though the black of the main barrel is merely excellent and the knurled (anodized?) rotating ring has a slight purple tinge (not visible in the pictures).

tewe 35mm
tewe 200mm

Tewe at (slightly wider than) 35mm and (a whisker over) 200mm

The  longer index, with the blob, is for subjects at infinity; the smaller index is for those at 20 focal lengths, e.g. 700mm (call it 30 inches) for a 35mm lens; 1000mm (1 metre, 40 inches) for a 50mm; and 4000mm (4 metres, 15 feet) for 200mm. Tying field-of-view compensation to focal length, rather than to absolute distance, makes for more accuracy, though it also requires more mental arithmetic.

Actual engraved, numbered focal lengths are 35 - 50 - 75 - 85 - 100 - 135 - 150 - 180 - 200, together with two further 'blob on a stick' white indices which presumably correspond to 90mm and 127mm. If it seems odd that 85mm is engraved, but 90mm not, the answer probably lies on the one hand in getting as many numbers as possible onto the ring -- 90 would have precluded both 85 and 100 -- and on the other in the fact that while the 5 inch (127mm) focal length was not common, it was used by Leitz New York (for a Wollensak lens) from 1948 to 1952. The omission of the relatively common 105mm focal length (Leica, Nikkor, Soligor, Meyer and maybe others) is a slight surprise.

Going beyond 135 was odd but there have been a few long, rangefinder coupled lenses including the famous 180/2.8 Olympic Sonnar for the Contax; Robot offered a 150; and Meyer had made 6 inch (150mm) Plasmats and Telemegors and a 7 inch (184mm) Telemegor, all uncoupled (!) for the Leica. For that matter there were extension tubes which replaced mirror housings and were used with e.g. the 200 Telyt on a Leica: the Tewe would be a lot easier to use than a SFTOO tube finder with a 200mm. An auxiliary lens (which I have never seen) is needed for 28mm and 30mm.

tewe 85-90

This close-up of the 85-90 setting shows two things. First, the (slightly surprising) fact that the angular field of view of an 85mm lens at 1.7 metres (call it 6 feet) is just about identical to that of a 90mm lens at infinity: a worthwhile illustration of the truth that fixed-size frame lines can only be accurate at one fixed distance. Second, you can clearly see the use of a blob-on-a-stick for intermediate focal lengths: here 90mm and 127mm, 5 inches, where there's no room for the extra engraved numbers.

There is also a red blob-on-a-stick just inboard of 35mm, which I suspect to be for use with either 28mm or (more likely) 30mm; 28mm would then be the 'beyond 35mm' setting seen above. The red blob is visible in the first and second pictures in the module. It might also work well for 38mm.

 As well as being made in the standard 24x36mm size, the Tewe was reportedly also made in 24x24mm (for Robot and one or two other cameras) and I have heard rumours of a half-frame version though I have never seen one. It can of course be used for any other camera with the 2:3 aspect ratio, such as 6x9cm. The diagonal of 6x9cm is about 101mm so a conversion factor of 2.3x is good enough. Thus a 150mm lens on 6x9cm equates pretty closely to 65mm on full-frame 35mm.

Conversion factors can also come in handy with the Leica M8 and M8.2, where a 4/3 correction factor needs to be applied to get the corresponding field of view for full-frame lenses: a 24/25mm lens is probably OK at the widest setting, though of course this is built into the camera. Rather more useful might be 40mm, 85mm, 100mm, 105mm and 135mm: the equivalents are 53mm, 113mm, 133mm, 140mm and 180mm. Only 180mm is marked but the others can be interpolated easily enough.

5 metre, infinity
6 ft, close up

Infinity (left) and close up (right)

The finder on the left is in metres (1 - 2 - 5 - infinity) and the one on the right in feet (3 - 6 - 15 - infinity) -- though the units are not marked in either case. The production of imperial and metric models was quite common in the 1950s: many lenses could be ordered in either form. The simple tilt around the front 'axle' is easy to see.

two tewes

Apart from the feet/metre markings and the serial number, our two Tewes are identical. We have heard of finders that stop at 150mm, but we have never seen one.


The serial number is on the base -- 6970 (right) is our metre model, and 04462 our feet model -- and 'Germany' is engraved on the mount under the eyepiece. Of course everything is superbly finished: all markings save the these two are paint-filled, and all save the serial number are engraved. The serial number is of course merely stamped.

tewe base

tewe on M2

 

Mix and match

Leicas prior to the M4-P did not have a 75mm frame, and frankly the frame on the M4-P is not all that good. A Tewe finder is an excellent solution, and a lot cheaper than a newer Leica. Other accessories seen here include an Abrahamsson Rapidwinder trigger base from about 2007 and a 'no-name' (and heavily brassed) rewind adapter from the 1970s. The camera dates from the early 1960s. This picture gives a good idea of the size of the Tewe.

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© 2010 Roger W. Hicks