SLR: The CAT did it

It’s damn near impossible to read any photo magazine article on shooting sports, animals, or birds without learning that many of the best shots required a huge, heavy, 500mm- or-longer lens, which few of us own. And many of you, I suspect, have attended professional sporting events and seen those poor photojournalists on the sidelines sweating under the burden of monster lenses.

Amateurs are often advised that they can closely duplicate pro results with shorter-focal-length lenses and a teleconverter or two. Well, maybe, but don’t count on sharp corners and edges or wide apertures. Even the main subject may not have snap.

Now picture this: You’re sitting in the back row at some grand sports event, too far away to see much. Your friends are sitting on their hands with useless cameras in their laps. Oh, for a long tele lens to bring back a great shot! With that, you pull from your coat pocket a lens about 19 percent smaller than a can of dog food, attach it to your camera, and fire away.

“What the devil is that?” you are asked. “Why, it’s a 500mm mirror lens,” you explain. “I just bought it for $69.” Then, to get a close-up, you slip a 2X converter between lens and camera body and shoot, handheld, with a 1000mm lens.

Daydream? Not a bit. Keep reading, and you shall know all.

Now that I’ve left you hanging there, let’s go back to the 1950s, when photojournalists were just beginning to throw away their rangefinder cameras for SLRs. Many of these photographers were covering uprisings, miniwars, and civil-rights skirmishes, complete with ferocious police dogs and water cannons. They needed tele lenses to keep them out of the line of fire but still close to the action. We called these 400- and 600mm lenses “giant stovepipes,” for obvious reasons: The bulky things were long on millimeters and short on portability.

Help came along from the unlikeliest place-the U.S.S.R.

In 1944, Russian scientist Dmitri Maksutov perfected a small, reflecting, 500mm f/8 telephoto mirror lens, based on a telescope design. It was but 5 1⁄2 inches long, and weighed 2 pounds, 9 ounces.

The Maksutov lenses, each packaged neatly in a beautiful wooden case with red, orange, yellow, and neutral-density filters, were discovered by photojournalists traveling through Moscow. Most bought one for themselves, and one to sell in the U.S. Later, a Russian trading company began importing them. At under $200, they were scarce, but highly desirable.

U.S. photographers snapped up the lenses, attached them to their cameras with screw-thread adapters, and added a 2X converter when action got too tight for the 500mm alone. This combo produced a 1000mm f/16 lens. Using high-speed (ISO 400) film with their MTO (Maksutov Tele-Optic) lenses, leading U.S. photojournalists were able to take great news pictures. The compact, lightweight lenses were easy to handhold. Photographers became accustomed to using speeds of 1/250 sec or even slower, with a bit of elbow bracing on floors, chairs, tables, car-window ledges, and roads.

Japanese lensmakers quickly hopped on the mirror lens bandwagon, and soon 500mm f/8 mirror lenses in all forms, shapes, and sizes were available from major and off-brand lensmakers. Amateurs had an optical field day with them. Besides being highly useful teles, many also focused extremely close-to 1:4; some, even closer. Warning: These lenses often came up fuzzy when macrofocusing. Called catadioptric (or simply CATs) based on their optical formulas, the lenses started at about $80, and had a great run among pros and amateurs alike. Then, just as suddenly as they had multiplied, they virtually vanished in the 1980s.

Major camera and lensmakers went back to producing larger, bulkier, all-glass transmitting lenses. What happened? Probably one or all of the following reasons:

1. Donuts went out of fashion. The secondary mirrors, located centrally in each CAT lens, produced round, black centers in out-of-focus highlight circles At first hailed as a nice artistic touch, photographers grew tired of donuts, and picture editors began to look on them with disfavor. What I think: I still find that donuts add interest to pictures, but if you don’t like ’em, avoid out-of-focus highlights. See my photographs.

2. Many 500mm f/8 mirror lenses turned out to have less light transmission and more focal length than marked. The MTO, for instance, was closer to a 550mm T/9.5 (T being the true light transmission), thanks to the secondary mirror, which not only produced donuts but also held back some of the transmitted light rays. What I think: With ISO 800 and 400 film what does a loss of f/8 to T/9.5 amount to anyway? Only a half stop.

3. Mirror lenses only have a single, smallish aperture that many pros and amateurs found objectionable, especially when using relatively slow film. Others wanted even smaller apertures to cut down on transmitted light. Attaching ND filters is the inconvenient way to do this, but ND filters do not increase depth of field as a smaller aperture would on an all-glass lens. What I think: F/8 (or T/9.5) is a good shooting aperture. I have a set of such ND filters for my CAT lens, and I’ve never used them.

4. Some mirror lenses produce considerable light falloff at the picture edges. What I think: Unless you’re shooting a natural-light subject, such as a blue sky, chances are you won’t notice the falloff. The wide exposure latitude of print film may also hide the falloff completely.

5. Mirror lens manufacturing requires high-precision components and assembly. Many lenses, particularly those made by small factories for off-brand labeling, are not of high enough quality. What I think: Try before you buy. Make sure you can exchange lenses or get a refund if your mirror lens is a dog. But remember: Don’t be too surprised if the macro settings yield poor results.

6. With the advent of autofocus SLRs, AF-mirror lenses weren’t available (except one, as we shall see). Manually focusing an f/8 mirror lens on an autofocus SLR viewing screen requires great care. Older SLRs often have split-image rangefinders, but with a 500mm f/8 they are usually unusable since one of the rangefinder semicircles goes black. What I think: If I can focus manually on SLR groundglass screens, so can you.

Mirror lens you can buy new

|| |—| | How it works: Folded loght path keeps mirror lens compact| | | Light from subject enters corrector lens, at left, travels to main mirror, is reflected back to secondary mirror, is reflected again through a hole in main mirror to field-flattener lenses, then through any filter in place, and finally to film or sensor at the focal plane.| Yes, there is an excellent autofocus 500mm f/8 mirror lens: the 4 5⁄8-inch- long Minolta AF, weighing 23 ounces, and focusing to 13 feet. If you have a Minolta Maxxum, you’re in luck. But you’ll need more than luck; you’ll need around 500 bucks! Worth it? I think so.

Sigma and Tamron also produce outstanding light, compact, manual-focus mirror lenses. The Sigma is a 600mm f/8, weighing 23 ounces, and focusing to 79 inches (approx. street price: $380). The 500mm f/8 Tamron weighs 23 ounces, focuses to 67 inches (1:3), and has a street price of about $435, including its adaptall mount.

And now comes what must be the best bargain in new mirror lenses ever. The 500mm f/8 Phoenix (made in South Korea by Samyang) is 11 1⁄2 ounces, 3 3⁄8 inches long, and focuses to 67 1⁄2 inches (1:2.7), though it’s not too sharp that close. It comes with a soft pouch and three rear screw-thread filters for…$100!! That’s Adorama’s price. But you can, of course, check with your favorite local dealer, who can probably order it for you if it’s not in stock. You’ll also need a T-mount lens-to-camera-body adapter, $15-$16; for Leica Rs, $20.

I did promise you 500mm f/8 lenses for $69, didn’t I? How’s your sense of adventure? When 500mm f/8 lenses fell out of favor, many were traded in or sold, and have remained paperweights on the used-equipment shelves of major camera stores such as Adorama and B&H Photo. The inexpensive ones often bear U.S. importer- or store-brand names such as Cambron, Sakar, Kalimar, Rokunar, or Soligor, and can vary in price from $60 upward. All each needs to be functional again is a T-mount screw-thread adapter. Yes, there are manual T-adapters that will allow manual focusing on Canon, Nikon, and Minolta autofocus cameras. (If you need to unlock a Minolta Maxxum to use the T-adapter, send me a self-addressed, stamped envelope and I’ll mail you the directions on how to do it.)

Trying to locate used 500mm f/8 lenses on store web sites can be quite wearying. It’s best to call the store’s 800 number, and ask for the Used Equipment department. You’ll likely be transferred to a salesperson standing near the lenses, who can describe them to you and offer some advice. But remember, as I’ve said, these are high-precision optics. They can easily go out of wack. And you don’t want one that’s been dropped from the top of the Empire State Building, handled carelessly, or has been an optical dog since birth in the lens factory. See my directions on how to buy this type of lens and how to use it.

I hope the three photographs I’ve shown will inspire you to get into the tele swing with a 500-600mm mirror lens. I shot all handheld, both with and without some bracing, at speeds from 1/30 to 1/125 sec. Whether you wind up with a $500 Minolta Maxxum AF lens or a $69 marvel, you can make great pictures with these remarkable little tele babies, and have a lot of fun doing it. Good hunting!

What used mirror lenses might you find?
Here’s a sampling of my lifetime collection, rare and not so rare, clockwise from 12 o’clock: Swift Lynx Catadioptric Spotting Scope, Spiratone 500mm f/8 Mirror-Ultratel, Questar astronomical-terrestial telescope, Vivitar 450mm f/4.5 Series 1 VMC, Sigma 400mm f/5.6 Mirror Telephoto, no-name 500mm f/8, Cambron 500mm f/8 reflex, no-name 500mm f/8, Tamron SP 500mm f/8 Tele Macro, Minolta AF 500mm f/8 reflex, redesigned MTO 3M-5A 500mm f/8, and Questar 700mm f/8. Center: original Russian 500mm f/8 MTO in wooden box with filters.

How to buy a used mirror lens

|| |—| | | Bargain hunter’s delight: How much for a small, compact, used 500mm f/8 mirror lens? Anywhere from $60 up. Any good? Better test it.| 1-Call photo stores and ask for the Used Equipment department. Inquire about the availability of mirror lenses in the 450-600mm range.
2-If possible, go to the store with your camera body to examine lenses yourself. You can probably try lenses right there and maybe even shoot some test pictures at the store.
3-If an in-person visit isn’t possible, ask the salesperson to describe lens by phone: indicate its size, weight, close-focusing capability, price, warranty, and shipping and handling costs. Check on the price of a T-mount for your camera. Make sure you can get a money-back guarantee.
4-When you receive the lens and T-mount, attach them together and then to your camera body. If lens scales are not at top, loosen three T-mount screws with a jeweler’s screwdriver. Turn lens so scales are upright on camera, tighten screws.
5-Make a quick, simple lens test: On a bright day, load camera with ISO 400 print film. Find a set of buildings or a scenic with details at infinity that appear at the center and edges in your viewfinder. Place camera and lens on a suitable tripod or other support. Focus carefully on subject using camera focusing screen. Select aperture-priority autoexposure. Ask your photofinisher for an 8×12 enlargement. Examine sharpness at center and edges. If the sharpness pleases you, keep the lens.
6-Alternatively, make a more precise lens test: Load up with ISO 100-200 fine-grained slide film. Find a detailed building façade at least 25 feet away that is parallel to your tripod-mounted camera’s film plane. Shoot as in 5. Now, change lens and mount one of your non-mirror lenses that you know to be sharp. Approach the building until you frame the same view as the one you shot with the mirror lens. Make an aperture-priority exposure at f/8. When slides are processed, compare results using a 10X or greater magnifier. Quality of mirror lens photo should approach picture made with your non-mirror lens. But don’t expect the mirror lens picture to equal it.

Eight tips for using mirror lenses
1. At close range, stationary subjects are easiest to shoot. My bird remained perched long enough for me to focus carefully; the matador stood stock still waiting for the charge of the bull; the lion and I stared at each other for quite a while.
2. To handhold lens steady, rest lens in left palm. Hold camera to your eye. Draw arms and elbows into body as far as possible. Press shutter release very gently.
3. Buy a beanbag. When using a tripod is inconvenient (which it often is, since handholding a lens gives you so much more fun and freedom), try resting your lens on a beanbag if you can. Most camera stores have or can order them. Plastic pellet-filled bags are lightest and best. Figure on spending under $10.
4. While the old rule of thumb calls for you to use the reciprocal of the focal length as the slowest shutter speed (1/500 sec for a 500mm lens), if you practice, you’ll be able to shoot at 1/125 or 1/250 sec. With bracing (see bird and lion photo captions), even 1/30 sec is possible.
5. For a fairly accurate check of your lens’ light transmission, aim lens on camera at a clear blue sky, an evenly lit wall, or place directly on top of light table. Check the shutter speed reading using aperture-priority mode. Replace mirror lens with one of your regular lenses and make the same reading at f/8. The difference in the shutter speed indicates the approximate true light transmission loss. For instance, if your mirror lens gives you a 1/60 sec reading but your regular lens shows 1/125 sec, that’s a loss of a full stop. So that mirror lens would have a light transmission close to T/11. Mirror lenses can vary from 1⁄2-to 1 1⁄2-stops of light loss.
6. While many mirror lenses may have light transmissions less than the f-stop markings, conversely the focal length is often greater than marked. While there is no easy, precise way to check true focal length, you can find if there is a large discrepancy between actual focal length and marked focal length. While in a camera store, ask to check out a 500mm tele or zoom set to your mirror lens’ focal length. View the same focused area with both lenses. Note how much greater the mirror lens image probably is. Some cheap mirror lenses may indeed have shorter focal lengths than marked. This method lets you check it.
7. The focusing ring of your mirror lens will probably revolve further than the infinity or closest-focusing markings on the lens barrel. Worry not. This is merely an allowance for the lens barrel’s expansion or contraction due to temperature fluctuations.
8. For shots within range, don’t forget to use flash when possible to freeze action and minimize the effects of camera shake. But make sure your flash beam clears the barrel of the lens.