Yearning to give your videomaking a new look? Creative special-effect visuals are only a lens manipulation away.

If you’re a photographer turned videomaker, you’re probably already familiar with the tricks of the lens trade. If you’re new to the game, however, prepare to let your videomaking creativity soar.

Getting super close-up shots out of a lens that wasn’t designed for it is just one of the possibilities that await you in the world of camera lens manipulation.

You can create dazzling special effects and change color, contrast, or brightness of a shot. Dreamy scenes, multi-image effects, psychedelic experimentation-all possible, conveniently and usually inexpensively.

Is Lens Change In Your Range?

Removable lenses are currently a rarity on consumer-level “home” video cameras and camcorders. As the personal-video phenomenon continues to grow, however, manufacturers hopefully will recognize the market for video cameras/camcorders with removable lenses.

Most industrial and professional video cameras come with a standard C-mount lens, which simply screws off. You may even be able to trade lenses with a 16mm motion picture camera, since many of them also use standard C-mounts.

Because you’ll be able to swap lenses with other cameras or buy specialized lenses for yours, we can all look forward to the day when we’ll be able to buy a home video camera that uses a removable lens.

C-mounts are usually found on cameras which employ a standard 1-inch or two-thirds-inch wide Vidicon tube. Consequently, C-mount lenses have a rear opening that matches the Vidicon. Some home video cameras and a few cheaper industrial cameras may use ball-inch Vidicons and thus a half-inch lens. When removable, they’re called D-mounts.

There are even adapters which allow C-mount and D-mount cameras to be used with “P”-type, “T”-type, or “bayonet” lenses from 35mm still-photo cameras. With these adapters you can use your expensive still-photo camera lenses on your video camera.

There is a little complication called format which should be of interest to you if you should ever swap lenses between dissimilar cameras. Format refers to the size of the image the lens projects onto the sensitive face of the camera’s Vidicon tube.

Cameras with two-thirds-inch Vidicon tubes need lenses that make the same size picture; these are called two-thirds-inch format lenses. A two-thirds-inch Vidicon tube is just about the same size as those used with 16mm motion picture cameras, so lenses designed for 16mm models often work well with video cameras.

If you should ever use a 35mm lens on your video camera, you’ll notice something funny happening-your image will appear to be zoomed in some. This is because your camera tube is only looking at the middle part of the lens’ picture.

Compatibility Counts

To work properly, the lens format must match the tube size-but there is room to cheat a little. If you wanted to, you could use a larger-format lens on a smaller camera if the lens mount fit. Because the lens would make an image that was too big, the picture would appear zoomed in more than it should, though still satisfactory.

If, on the other hand, you tried a lens designed for an 8mm movie camera on your half-inch or two-thirds-inch video camera, the image would be too small. The tiny picture wouldn’t cover the entire face of the Vidicon tube, and would create a vignette effect.

In this case the vignetting would be obvious, but in cases where the lens and camera are almost matched, you may only see the vignetting when you zoom out all the way.

If your camera’s lens is not removable, all is not lost. Often this applies to cameras with through-the-lens view-finders or special features such as auto focus, auto iris, electric zoom, and fade-to-black.

You can always buy lens attachments which fit on the outside of the lens to teach it new tricks (covered later). However, videomakers who enjoy the luxury of removable lenses will appreciate greater flexibility

Removable Lens Options

Close-up shooting is only one of the many things you can do with a video camera. It has been my experience, however, that TV is a medium that begs for close-ups-the tighter the better Super-tight close-ups jump off the screen at you. Pictures, objects, and print all come alive as the camera scans them from inches away.

Unless you have a macro lens, capable of focusing very close, you may find yourself not being able to focus on anything closer than 3 or 4 feet with your camera’s regular zoom lens. You’ll find, however, that if the lens was positioned farther from the camera, it would become “nearsighted.”

Since the lens can’t float out there in mid-air, you need to use a lens extender; a little pipe that fits between your camera and your lens. You will no longer be able to stay in focus automatically while you zoom, but you will be able to focus on objects very close to the lens.

Another handy gadget is the tele-extender; or telephoto converter. Like the lens extender, it fits between your camera and your removable lens, but it contains glass elements of its own which can turn your ordinary lens into a telephoto lens.

A 2x telextender, for instance, will convert your 12.5mm to 75mm zoom lens into a 25mm to 150mm zoom lens. Furthermore, your lens should stay in focus throughout its zoom range.

Using a telextender is much cheaper than buying a new lens for your camera, It is somewhat cumbersome, however, because you must disconnect your lens, mount the telextender, and remount your lens whenever you wish to change from normal view to telephoto view.


The Attachment Route

If you’re not blessed with a macro lens and your video camera has a permanently mounted lens, there is still a way to get super close-ups: Go down to your local camera store and get fitted for close-up lens attachments. Simply unscrew your lens shade, screw on the lens attachment, and screw the lens shade onto the attachment.

Close-up lens attachments also have the advantage of allowing you to zoom the camera during close-up shooting (macro lenses don’t allow you to do this).

These attachments come in various powers: +1 diopter, +2 diopter, +3 diopter, etc. The higher the” + “number, the “stronger” the lens attachment. These attachments don’t necessarily magnify the picture per se; instead, they make your lens more nearsighted.

Where you could normally shoot from 4 feet to infinity, a 1 diopter close-up lens attachment lets you shoot from about 1.5 to 3 feet, and a +2 diopter lens attachment gets you from 1 to 1.5 feet. Up to +3 diopters, your image will stay sharp throughout its zoom range. Above that, it becomes increasingly necessary to refocus as you zoom in order to maintain a sharp picture.

Close-up lens attachments are usually threaded so that after one is screwed onto your regular lens, another close-up lens attachment can be screwed on-sort of piggyback.

In such cases, the diopters are additive. For example, a +2 lens added to a +3 lens is equal to +5 diopters in power When stacking lenses, the higher diopter lens should be nearest to the camera and the curved part of the glass on both attachments should always face out.

Adding Lenses, Subtracting Frustration

Adding lenses tends to decrease sharpness and brightness, especially in the corners of the picture. To combat the blurriness caused by using several lenses at once, flood the subject with light and stop your iris down to f16, if possible.

You will probably not find exactly the right size attachment to fit your camera’s lens, but don’t despair. Stepping rings let you adapt from one size to another. All you need is one that matches the size of your camera’s lens and your lens attachments. Always buy attachments that are at least as big as your camera lens to avoid vignetting.

Incidentally, when using any lens attachments, be sure to screw them on gently. When screwed on too tight, they tend to seize up and become nearly impossible to remove. If you do get into such a predicament, try the following trick for removing a filter or lens attachment.

Screw a lens shade onto the attachment; if you have a lens cap that goes over the lens shade, put that on too. Now try twisting the three off together. Here’s another trick while we’re at it: If a lens shade is hard to remove, place the lens cap on it first, then try unscrewing it. The cap holds the shade perfectly round so it doesn’t bind while unscrewing.

Filters: Fun and Functional

Every camera lens should have a skylight (1A) or haze (UV) filter attached at all times. This nearly clear lens absorbs ultraviolet light and removes excessive blues from open shade. It never hurts The picture, and sometimes even helps it a little.

Its purpose, however, is not to improve the picture but to protect your regular camera lens from damage. It will block out water, fingerprints, scratches, and blowing sand. When it gets dirty, you can unscrew it and wash it; if it gets damaged, simply throw it away and buy another (Try that with your $100 video camera lens!)

Also popular is the polarizing lens. Just like your Polaroid sunglasses, the polarizing lens reduces outdoor reflections in glass, pavement, chrome, and water. It deepens blue sky and whitens clouds. By reducing bright reflections, it may even protect your sensitive Vidicon tube from burn-ins.

In order to work properly, your polarizing lens must be oriented the right way. Try rotating it while looking through your camera and you’ll see reflections and highlights disappear and reappear as it rotates. The object is to rotate the polarizing filter until most of the reflections disappear.

The task can be difficult if the filter is screwed tightly onto a camera lens which rotates as it focuses. You may need to unscrew the filter a little so you can focus the camera lens and re-orient the filter without affecting the focusing.


Set for the Scene

Neutral density filters are handy if you do a lot of shooting in very bright sunlight, on beaches, or in the snow. Your scene may be so bright that your camera is always stopped down to f16, giving you tremendous depth of field.

Great depth of field makes focusing easy but certain situations call for poor depth of field, such as when you want to center attention on a foreground object while the background remains blurry.

In this case, light must be eliminated another way so that the camera’s iris can be open to fl.2 or so, lowering its depth of field. This is where the neutral density filter comes in: a dark piece of glass which cuts out light. These filters come graded by darkness (ND-X1, X2, X3, etc.). The higher the “X” number, the darker the filter.

Low-contrast filters, as the name implies, reduce contrast. Sometimes you get into a situation where something very bright and something very dark exist in the same picture, and you need to tone one of them down.

Professional video cameras have a pedestal or setup control, which allows the dark parts to be brightened without affecting the rest of the picture, thus reproducing both extremes of the contrast range.

If your home camera doesn’t have these controls, you might try a low-contrast filter, made of a slightly foggy glass which diffuses the light, making a picture’s dark parts lighter. Filters with a small degree of diffusion won’t harm your picture, but will create a smoother film look.

While soffening the picture, low-contrast filters reduce some detail. This function is advantageous if you’re taking portraits and wish to make the subjects’ blemishes or wrinkles disappear. Filters with more diffusion can create dreamier, foggier effects.

If you don’t wish to buy a professional diffusion filter, you can try making one yourself by placing gauze or nylon hose over the lens, adding layers to increase the effect.

More Filters to Fit Your Fancy

Star pattern filters accentuate highlights by extending white streamers in four, six, or eight directions from every bright point on the picture.

A shoestring version of this effect can be created by either placing a wire window screen over your lens or by smudging a little baby oil in one or two directions across a piece of glass in front of the lens.

Center sharp lens attachments create interesting effects by leaving the center of the image sharp while defocusing, fogging, or streaking the outside edges of the image.

You can fake this effect for yourself, too. Simply rub a little Vaseline in a circle on a piece of glass, leaving the center clear The direction in which you streak the grease will affect the direction of the highlights, and the amount of oil used will affect the amount of distortion you’ll get at the edges of the image.

A multi-image lens attachment is made of faceted glass which turns one picture into five or six images. A “greenish-yellow” (GYS) filter removes blue from the scene-useful for landscape or aerial shooting because it corrects for the bluish haze in the air.

Graduated filters are a lot like those sunglasses you see which are dark at the top and clear at the bottom. A blue graduated filter could, for instance, turn a white sky into a blue sky while not affecting the foreground.

A neutral density graduated filter will darken the sky while leaving the foreground lighter. A red tint at the top of the filter could darken a blue sky to black, creating “pseudo-night” effects.

As you can see, there are many ways to spend money on lenses affer you’ve spent your last cent on your video hobby. But lens accessories, adding dimension and flexibility to your existing video camera lens, deserve more attention than they usually get.

The lens, after all, is the eye of your camera.

Peter Utz, a college media department director and videomaking instructor; is the author of Video User’s Handbook, The Complete Home Video Book, and Do-lt-Yourself Video (Prentice-Hall)

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