A Lightweight M-System Using the "Crop Factor"

In the good old days of Kodachrome, color photographs were submitted to publishers in the form of slides for best reproduction -- not prints, as had been the case with black and white. Therefore a pro photographer specializing in color was obliged to carry SLR cameras with a considerable range of fast lenses in order to get each shot framed correctly for submission to editors. Zoom lenses were slow and heavy and not very good, so it was mostly up to a set of individual prime lenses to get the shots framed correctly on the slow slide films of the day.

A lot of that changed with the take-over by digital. Color pictures could then submitted electronically which allowed cropping of the pictures before submission -- and/or small corrections to the images -- made by the photographer using  computer programs such as Photoshop. The ISO in the camera could be increased when light was low so the lenses could be slower, even if the image quality deteriorated a bit when the ISO was pushed too high. However the total weight of equipment  carried all day in the bag didn't change much. It now consisted  of one or two DSLRs with rather large and heavy zoom lenses  usually in three ranges -- superwide such as 12-24mm, normal 24-70mm, and longer telephoto. Total weight was still approaching  the twenty pound range.

With slide film the M camera and lens set was somewhat  smaller and lighter, if we could do without the longest focal lengths and macro capability. A typical M set was 21-28-35-50-90-135, ignoring newer in-between lengths such as 24 and 40 and 75. Five or six lenses were usually needed in the bag to frame the slides. And usually two camera bodies needed so that two prime lenses could be used at the same time This meant that weight and complexity were still somewhat of problem.

But if weight has already begun to be a problem, digital  submission has provided a particularly good solution for color  work, especially with the M cameras. Courtesy of the new "Crop Factor", as I like to call it, we can now cut that six M lens rig exactly in half by carrying only 21 and 35 and 90 with each lens doing the work of two or three. This is how it works:

Take a 35mm M lens, for instance. Small, light, and fast, used in its "normal" mode it does just about anything from a large landscape to a small group in extreme low light. But what if a 50 is suddenly wanted for an individual portrait or a middle distance shot? The old way was to take the time to switch to a 50 or use a second camera with a 50 on it so the slide was  properly framed. But now, with cropped electronic submissions, we can use the 35 in horizontal mode and crop the picture square to look just like a 50 shot. Since the short side of the 35 picture is the same dimension as the long side of a 50 frame, a squared-oft 35 shot is therefore made at the same distance as a vertical or horizontal 50 shot, and showing the same perspective. The 35 can now do the work of two lenses -- much the same as the old days of b&w and the home darkroom -- but these days with ISO 400 color neg film or digital there isn't the grain that Tri-X used to show when blown up and cropped.

Used in this way, the Crop method can make a 21 produce 21 or 24 or 28mm pictures, a 35 can produce 35 or 50, and a 90 produces 90 or 135. That's six or seven focal lengths already. But even more is possible. The 21 can sometimes back off a little and approximate the coverage of an 18mm, for a total of 18-21-24-28. The 35 can sometimes back off to approximate a 28 for total of 28-35-50. And a 90 can do 75-90-135 (which can give you the equivalent of a rangefinder 135mm f/2, by the way!). So the 21-35-90 rig can now do the work or 18-21-24-28-35-50-75-90-135 -- equalling the full range of the old set of six lenses.

This small and lightweight three-lens outfit can do just about anything, anywhere, all courtesy of being able to submit cropped pictures instead of slides. Bag weight feels light compared to the six or seven lens Leicaflex SL outfit I lugged around in a big aluminum Hallibuton case during those good old days of Kodachrome. And, by the way, Leica is already starting to use something like this crop method in the Q (Typ 116) camera With its 28mm f/1.7 summilux which, using the Digital Selector Mode, can be cropped down to 35 or 50 with the loss of a few megapixels. The Crop Factor system with M cameras uses this same approach, but providing a much great-er range of focal lengths available in the bag.

Closeup ability will be limited to the 90 at one meter, cropped down to 135 or so, unless special macro gear is included in the bag. Longer telephoto lenses are not really the province Of the rangefinder cameras. If needed, these areas can be covered by an additional reflex bag carried carried separately. But even with its limitations, the little 21-35-90 M camera bag will do just about anything that is wanted in one way or another, and the smaller size and lighter weight are apt to be very toward the end of a long day.

The author’s minisystem: It consists of Leica M6 with 21mm f/2.8 Elmarit-M with plastic-bodied 21mm brightline finder, the lens having an E60 to E62 step-up ring which serves as a minimal hood which intrudes as little as possible into the finder’s view. In the center is a 35mm f/2 Summicron-M ASPH. And on the right is a 90mm f/2 Summicron-M, shown with its usual rubber band on the focus ring to provide extra grip.