Here's an example of using a telephoto to achieve a tight cropping at the Malakoff Diggings State Historical Park in California's Gold Rush Country. Any other camera position would have meant shooting from the canyon floor. Photos © 2002, Joseph A. Dickerson, All Rights Reserved

Tele Lens Design
The principles of telephoto lens design were discovered by Barlow over 150 years ago. In 1891 these principles were simultaneously applied to photographic lenses by Dallmeyer in England, Dubosq in France, and Meithe of Germany. Barlow discovered that the use of a negative rear lens element allowed lenses to be designed that had a shorter lens-to-film distance than a normal-type lens of the same focal length. With studio monorail cameras this is rarely an advantage, but with compact field cameras the bellows draw is often inadequate for longer focal lengths. Closer focusing requires the bellows to be extended even further, something not possible for many field cameras on the market today. A telephoto 300mm lens needs less bellows extension, which allows a camera with a 12" bellows to focus closer than infinity. This becomes even more critical when the photographer wants to employ still longer focal lengths.

One other salient point is that there is no other advantage to using telephoto lenses. They are not inherently superior, or for that matter inferior, to long focal length lenses. Their only advantage is their physical size. There are, however, some aspects of their use that can be confusing.

Using telephoto lenses with a rollfilm adapter increases the telephoto effect. This old shack was shot with a Fujinon 400mm lens with 120 film in a Horseman 6x12 film holder.

Telephoto Lenses And Close-Up Photography
When calculating the exposure compensation required for close-up photography with a view camera and a non-telephoto-type lens you divide the bellows extension (squared) by the focal length (squared) and the result is the bellows extension factor. A factor of four indicates a two f/stop increase is required, a factor of two a one f/stop increase, etc. But with a telephoto lens measuring the bellows extension to the lens itself will result in an inaccurate reading. Here's the trick. With a telephoto lens you first need to measure one focal length forward from the film plane or ground glass while the lens is focused on a distant object. Note the difference between the measured focal length and the distance to the lensboard. Then, when you are computing bellows extension add that difference to the measured bellows extension. It's confusing at first but when you work through it a time or two it will make sense.

The Nikkor T-ED 270mm has a large enough image circle to covaer 4x5 with a little to spare. This makes it ideal on a medium format view camera as it provides plenty of movements for roll film. Considerable front rise was used in this image.

We all use the Scheimpflug rule when trying to maximize sharpness with a view camera. You remember, if the plane of the film, the plane of the subject, and the plane of sharp focus meet at a common point you have optimum image sharpness. Well, Scheimpflug's rule still works with telephoto lenses but it's trickier because the nodal point is hanging out there in front of the lens instead of being inside the lens where it belongs. Essentially you'll need less tilt than with normal lenses, and it takes some extra fiddling about to get it just right.

One other thing about telephoto lenses is that they tend to have smaller image circles than comparable long lenses. Watch carefully for vignetting or image falloff as you start to use camera movements, and always check the corners of your ground glass after you've stopped down.

I have recently begun using a Nikkor T-ED 270mm lens on my medium format Gowland Pocket View. I find this lens to be somewhat sharper and considerably contrastier than the 1960s-era lens it replaced. The modern multi-coating probably accounts for much of this improvement. Test older lenses before you buy to make sure that the performance is adequate for your needs.

It's All In The Chart, Mostly
I've prepared a reference chart that lists some common large format telephoto lenses and their features. The chart is not meant to be all-inclusive, but I've listed as many lenses as I could find data for. Some are available new (see chart, page 80) and some will only be found on the used market. You might try finding them in the back pages of Shutterbug or at your local camera swap meet. If you're contemplating buying an older lens be sure and run through the shutter speeds to see if they seem accurate and check the glass by shinning a light through the lens while the shutter is open. If you see discoloration, separation, scratches, or fungus in the glass (fungus will show up as haziness in the glass) you should probably pass on the lens. If you find some minor problems but you've really just got to have it anyway see if you can return it if it fails a practical shooting test. By the way, older shutters will often slow down from lack of use and all they really need to get them going again is exercise. This can often serve as leverage to help you negotiate the price downward.

The Nikkor T-ED 270mm made this composition. There were too many distracting elements just outside the image area. They could have been eliminated by moving the camera closer but the camera would have to be in the middle of traffic.

One important characteristic that won't show up in my chart is bulk. View camera telephoto lenses are not petit. Quite the contrary, they're big and much of that bulk needs to fit inside your camera's bellows. Telephoto lenses also tend toward obesity, and that weight hanging off the front of your lightweight field camera may just be the last straw, so to speak. If you want to use a telephoto lens on your 4x5 field camera check first to make sure the front standard has the necessary strength to support it. The extra weight cantilevered off the front of the camera may also mean you'll need to upgrade to a sturdier tripod to eliminate camera shake. No sense spending good money on a sharp telephoto lens and then destroying image sharpness with vibration.

Where To Buy Telephoto Lenses Osaka Lenses and Other Cool Stuff
Bromwell Marketing
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