Optical Options: Lens Accessories for Camcorders

by Dave Welton
January 1995

Ever want to cram more horizon in your viewfinder by zooming out a bit further--but your camcorder refuses? Or maybe you desire to zoom in tighter to get a little closer to the action--but your lens just won't cooperate?

What can you do? Since the majority of camcorders have a permanently affixed lens, you're stuck with it, right? Not exactly. There are options. Accessory lenses offer expanded range for your camcorder's vision--extended zoom capabilities and a widened field of view.

In many cases a standard camcorder lens simply won't cut it. Here we'll explore devices that attach to a camcorder's lens to give the videomaker more creative control. We'll take a look at the different types of lens accessories, describe what they can do for you, and how to shop for them.

Lens Swapping
Those of you who shoot 35mm SLR (single lens reflex) photography already know about the advantages of interchangeable lenses. A still photographer might carry three or more lenses along on a shoot, selecting a different one for various situations.

Most professional video cameras don't even come with a lens; the buyer chooses one to suit their specific needs. On these cameras, the lens attaches to a certain type of mount, such as a bayonet mount. This makes it easy for the professional videomaker to swap lenses in the field.

But the cards seem stacked against the videomaker who is stuck with a permanently attached lens. Don't despair--external lens attachments can do the trick. These devices attach to the lens by screwing or snapping onto the threads on the front of a camcorder's permanent lens. Adapters, converters and other lens accessories can give videomakers some of the creative control of the interchangeable lens at a fraction of the cost of a professional camcorder.

The Promise of VL Mount
In 1990, engineers from Canon, Hitachi, Matsushita and Sony cooperatively announced a lens mounting system for consumer camcorders. These major players in the camcorder industry envisioned a day when a lens that fit, say, a Sony camcorder could be removed and attached to, say, a Hitachi camcorder.

They dubbed the breakthrough system the VL (Video Lens) mount. It permitted quick release of a lens and re-attachment to another camcorder body while retaining auto focus, iris and power zoom capability. Tiny electrical contact points located on the lens and camcorder body transferred commands for these vital lens functions. A locking mechanism securely attached the lens to the camcorder body.

The unveiling of the VL mount system signaled a future that held great promise. The consumer would finally share the lens interchangeability that video pros took for granted. Unfortunately, that promise has gone largely unrealized. Only Canon developed a camcorder using this technology. They included it first on the Canon L1 and now it appears on the new L2 Hi8 camcorder. They currently offer five diverse VL mount lenses plus a 2x adapter. Other manufacturers, like Electrophysics, are offering VL mount compatible equipment, and hopefully more will soon follow.

Until more manufacturers embrace the VL mount standard, lens accessories are the videomaker's only option.

Lens Basics
Before we go on, let's get some basic terms and concepts out of the way. We'll start with the lens itself. It's one of two essential components of a camera's image-gathering system--the other part is the light sensitive CCD (charge-coupled device).

Because lenses play an indispensable role in the quality of the images a camcorder captures, the quality of your lens has a profound effect on the quality of your work. If the glass isn't ground to precise tolerances, or the setting of the individual elements within the lens is off even slightly, the image becomes fuzzy and distorted. The same goes for lens accessories. If the materials or construction of an accessory lens aren't up to snuff, your image will suffer.

Typically measured in millimeters, focal length is the distance from where the light rays converge in the lens to the surface of the camera's CCD. This distance determines the width of the field of view. Short focal lengths provide a broad field of view (wide angle), while long focal lengths offer a narrow field of view (telephoto). It's focal length that most lens adapters modify.

Creative Control
There are aesthetic considerations to ponder when you vary the focal length of your lens. A longer focal length (telephoto setting) allows you to bring a subject into sharp focus while throwing the background into a blur. This comes in handy when shooting people against confusing backdrops.

The telephoto lens also compresses distant objects by making them appear closer together. A telephoto shot down a busy street makes the cars and people look even more crowded. When making a shot like this, you'd better use a tripod--a telephoto lens accentuates camera unsteadiness. A telephoto lens adapter will make the compression--and the unsteadiness--even more dramatic.

A wide angle shot gives the videomaker a reprieve from worrying about holding the camera still. Small wobbles and bumps shot through a wide angle lens are barely noticeable. Also, focus is less critical when shooting wide angle, especially when compared to telephoto shooting.

The only time a wide angle lens imparts a noticeable "look" to your video is when it's really wide. Called barrel or fisheye distortion, this effect makes straight lines on the edges of the image appear curved. It also dramatically enhances the apparent distance between objects, making anything close to the lens look comically huge. Attaching a wide angle or fisheye lens accessory your camcorder will net you these types of effects.

No Free Lunch
There's an optical price to pay when using lens adapters and accessories. An additional lens presents the possibility of distorting the image and reducing light intensity. Unwanted side effects include skewed colors, fuzzy images and problems shooting in low-light situations.

Look for accessories that use fewer lens elements---they'll have less chance of producing unwanted effects (though there are exceptions to this rule). Remember, you get what you pay for. An inexpensive converter will most likely take more of a toll on your images than a costlier model.

Some autofocus systems get fooled by lens adapters. This is more likely to happen on older camcorders without inner focus lenses. You may have to resort to manual focus.

Make sure the lens attachment you purchase will fit your particular camcorder's lens. Not all camcorders have threads the same size. (See accompanying sidebar for a listing of the thread sizes for common camcorders.)

Common lens thread sizes are 34mm, 37mm, 43mm, 46mm, 49mm, 52mm, 55mm and 72mm. Palm-sized camcorders typically have smaller lens thread sizes, and full-sized camcorders have larger ones. Check for the thread size marked on the front of the lens. If you can't find it there, check the specifications page of your owner's manual--typically listed under "lens diameter."

Ideally, you should use lens accessories that directly fit your camcorder's lens. But when that's not possible, a myriad of threaded adapters are available to solve the problem.

If you must adapt, start with lens accessories that are bigger than your lens. A smaller accessory might cause undesirable darkening at the corners of the image, called vignetting. This effect is most noticeable when you zoom to a wide angle setting. (Vignetting can also be a purposeful, artistic effect.)

Telephoto Converters
Now that we have the preliminaries out of the way, let's take a look at some lens accessories, starting with the telephoto converter.

The telephoto converter enhances the focal power of your camcorder by boosting its ability to capture distant objects. It does this by extending your lens's focal length and narrowing its field of view.

Kenko's KVC-20 ($85) 2x telephoto converter lens is one example. The adapter lens effectively doubles the focal length of your camcorder's lens--hence the "2x" designation. With the KVC-20 attached, a 10:1 zoom lens becomes a 20:1 zoom lens. The converter lens is just a bit over two inches long and will fit 49, 52 and 55mm camcorder lenses.

Other converter lenses typically range from 1.4x through a whopping 12x or more. Typically, the more powerful the converter, the longer and heavier the lens.

Sigma offers a variable focal length telephoto converter. The VZ-2 ($467) zoom converter provides 1.8x to 4x enhancement through a 16 element zoom lens design.

The Raynox "Insta-Tele" ($46) is a unique snap-on telephoto adapter that works with any lens from 34mm to 46mm. This dual-element adapter offers 1.8x enhancement and high-quality optical glass.

Wide Angle World
The opposite of the telephoto converter is the wide angle converter. This lens shortens the focal length and broadens the field of view of your camcorder's lens. One example is Raynox's XL505 ($44) 0.5x wide angle adapter, which reduces the focal length by a factor of 0.5. Like the Insta-Tele, Raynox's Insta-Wide XL attaches instantly to your camcorder's lens and fits any lens with a thread diameter between 43mm and 52mm.

Want the best of both worlds? Vivitar's model 058035 ($71.95) offers 0.6x and 1.5x conversion--it's both a wide angle and a telephoto adapter. The two-inch, 5 element lens fits 46, 49, and 52mm lenses. To switch between the two focal lengths, you simply remove the lens and turn it around. Ambico's V-0361 ($69.95) is a similar two-in-one design with 0.6x and 1.35x capability.

A "fisheye" lens goes a step beyond a basic wide angle lens by offering an ultra wide angle view. Here the lens playfully distorts reality, giving the fun house mirror look described earlier.

Conversion lenses with a rating of less than about 0.5x will give a fisheye effect. One example is Kenko's KUW-045 ($110), offering 0.45x focal length.

Up Close and Personal
If you want to get closer than your stock lens allows, try using a close-up lens, or diopter. They are available in varying degrees of magnifying power--the higher the figure, the greater the magnification. With two diopters attached together, the magnification factors are additive; attaching a +2 to a +3 is equivalent to using a single lens rated at +5. A +2 will render a wristwatch the size of a TV screen, while a +4 diopter will do the same to a dime. Using the two together makes a monster of an ant.

Vivitar offers a wide range of lens diopters, with ratings of +1 to +4. You can buy these individually, but it is more common to buy them in a set of 3 (+1, +2 and +4). Prices for these sets vary according to the size of the lens, from $31 for 49mm to $64 for 72mm.

Want to attach a diopter to your zoom lens? With most diopters, you can't do this without increasing the chromatic aberration (fuzziness or loss of resolution--remember?). Fortunately, a high-quality achromatic diopter can cure this problem. Century Precision Optics offers a full line of these diopters, from power +1 to +7. At $250 each, they will fit 58mm and smaller camcorder lenses.

You can achieve amazing--even awe-inspiring--effects with the intimate perspective that macro shots offer. A macro shot magnifies something very small to fill the screen. This makes the skin of an orange look like a lunar landscape, or a common pencil look like the trunk of a towering redwood tree.

There are many applications for ultra close-up work. You could single out one tiny person in a huge university graduating class photograph, or pan across the signatures of the framers of the United States Constitution a few letters at a time. In the science classroom, a few close-up shots of flora and fauna could come in handy. Or you could just have fun with it--the possibilities are endless.

To obtain crisp images and the greatest depth of field, macro shots require a large amount of light. Be careful not to block the light source with your camcorder. This is not always easy since the camcorder is so close to the subject. Also, you'll need to hold the camcorder steady, so use a tripod for best results.

Other Accessories
There are many other nifty gadgets that you can attach to your camcorder lens, including filters, periscopes, microscopes and miniature fiber optic lenses. The key to shopping for these is the same as with those mentioned above: find the right tool for the job you want to do, then try before you buy.

This means taking your camcorder along when you shop for lens accessories. Attach the accessory lens to your camcorder, right there in the store. Be sure it allows your auto focus to function properly and provides full zoom range without distorting the image. If you can, view the resulting image on a monitor.

And remember: just because you don't have a detachable lens on your camcorder doesn't mean you have to suffer. There are quite enough lens accessories available for you to exercise your optical options.

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Glossary of Terms

Diopter A lens attachment that enhances the close up (macro) capabilities of a lens.

Field of view The extent of a scene--or vista--that is visible through a particular lens. Sometimes called angle of view. Most lens adapters affect field of view.

Flare Bright flashes caused by excessive light striking the camera lens and reflecting off internal glass elements. Poorly-designed lens adapters can accentuate flare.

Focal length The distance from where the light converges in the lens to the surface of the camera's CCD. Determines how wide or narrow a vista a particular lens can "see." Most lens adapters affect focal length and field of view.

Macro A lens capable of extreme close-ups. Useful for intimate views of small subjects.

Telephoto A lens with a long focal length and narrow field of view. It captures magnified images from considerable physical distance. Opposite of wide-angle.

Vignetting Undesirable darkening at the corners of a picture due to improper matching of accessory lens to camcorder lens. Occurs most frequently when shooting at a wide angle setting through a telephoto lens adapters. Sometimes used purposefully for artistic effect.

Wide Angle Lens A camera lens with a short focal length and broad field of view; it offers a wide vista of a scene. Opposite of telephoto.

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Lens Thread Size by Camcorder Model

Manufacturer  Model       Lens Thread Size
Canon		UCS3		37mm
Canon		UCS5		46mm
Hitachi		2600A		37mm
Hitachi		VM-H57A		34mm
Hitachi		VM-H71A		46mm
JVC		GR-AX35		43mm
JVC		GR-AX55		43mm
JVC		GR-M7		52mm
JVC		GR-S505		52mm
JVC		GR-SX90		43mm
JVC		GR-SZ1		46mm
JVC		GY-X1TCU	72mm
JVC		GY-X2U		72mm
Minolta		8-912		46mm
Nikon		VN-720		37mm
Nikon		VN-760		52mm
Panasonic	AG-186U		49mm
Panasonic	AG-195U		49mm
Panasonic	AG-3		37mm
Panasonic	AG-455U		49mm
Panasonic	AG-460U		55mm
Panasonic	PV-810		49mm
Panasonic	PV-S372		49mm
Panasonic	PV-S64		49mm
Panasonic	PV-S770		49mm
RCA		Pro833HB	34mm
Ricoh		R-87H		37mm
Sharp		VL-HL400U	37mm
Sharp		VL-L63U		43mm
Sony		CCD-FX710	37mm
Sony		CCD-TR500	37mm
Sony		CCD-TR700	52mm
Sony		CCD-VX3		52mm

Can't find your model listed? Check the specifications page of your manual for more information.

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Accessory Lens Manufacturers

Not meant to be a comprehensive list.

Allegro
1900 N. Austin Ave.
Chicago, IL 60610
(312) 745-5140

Ambico
2950 Lake Emma Road
Lake Mary, FL 32746
(800) 621-1106

Azden
147 New Hyde Park Rd.
Franklyn Square, NY 11010
(516) 328-7500

Brandess Kalt
5441 N. Kadzi Ave.
Chicago, IL 60625
(312) 588-8601

Carter-Craft
2240 15th St.
Rockford, IL 61104
(815) 229-7773

Century Precision Optics
10713 Burbank Blvd.
N. Hollywood, CA 91601
(818) 766-3715

Eurotech Electronics
2 Industrial Park Road
Plattsburgh, NY 12901
(516) 566-9778

Innovision Optics
1318 Second St. Ste 27
Santa Monica, CA 90401
(213) 394-5510

Jasco
311 NW 122nd
P.O. Box 466
Oklahoma City, OK 73114
(405) 752-0710

Kalimar
622 Goddard Ave.
Chesterfield, MO 63005
(314) 532-4511

Kenko
17801 Skypark Circle Ste B
Irvine, CA 92714
(714) 251-9646

LPL
3-8-6 Nishiochiai Shinjuku-ku
Tokyo, Japan 161
810395342214

Philips Accessories
401 E. Old Andrew Johnson Hwy
Jefferson City, TN 37760
(615) 475-0471

RCA Accessories
2000 Clements Bridge Rd.
Deptford, NJ 08096
(201) 853-2583

Rosco
36 Bush Ave.
Port Chester, NY 10573
(914) 937-1300

Satter
4100 Dahlia St.
P.O. Box 7234
Denver, CO 80207
(303) 831-7481

Sigma Corporation
15 Fleetwood Court
Ronkonoma, NY 11779
(516) 585-1144

Tokina Optical
1512 Kona Drive
Compton, CA 90220
(213) 537-9380

Uniphot
P.O. Box 429
Woodside, NY 11377
(718) 779-5700

Vanguard USA
7202 W. Huron River Drive
Dexter, MI 48130
(313) 426-3470

VDO-Pak
413 Oak Place #3-M
Port Orange, FL 32127
(904) 756-9770

Vid-Cam-Optics
160 Hunts Lane
Chappaqua, NY 10514
(914) 238-3998

Vivitar
9350 DeSoto Ave.
Chatsworth, CA 91311
(818) 700-2890

Yoshida Industry Co.
Raynox brand
P.O. Box 194
Tokyo, Japan
03-987-4725

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