How to hold a camera steady at slow shutter speeds and in time or bulb exposures when you don't have a tripod handy is a constant challenge to photographers.

Of course, purists may say, "don't be lazy -- take along a tripod, you never know when you'll need one." But the fact is that we're all a bit lazy. Who wants to lug around a cumbersome piece of euquipment on the chance he might need it?

Out of this need have come the mini-or table-top tripods, monopods and other gadgets to circumvent the big tripod requirement.

The latest of these tripod substitutes is called Foto Pheet, a plastic clip-on with adjustable legs. I've tried it on my Nikon FM and it seems to give a steady enough base for time exposures. (If you're an interested gadgeteer, they come in two sizes for the slimmer and fatter 35s and can be ordered from Robert Frankel Foto Pheet, 11905 Woodbridge Street No, Studio City, California 91604 at $9.95 each).

Robert Frankel writes that the idea for his gadget came while he was traveling and needed to take time exposures of night scenes and building interiors. I've had the same problems myself.

The ideal way to make long exposures is by putting your camera on a sturdy tripod. Unfortunately, sturdy usually means heavy. A full-size tripod is a nuisance on a trip unless you are a real afcionado, or you are taking pictures for money. On the other hand, just because you are using a small camera, you should not make the mistake of using a flimsy, lightweight tripod.

The next best bet to a full-size tripod is a tabletop tripod that you can carry in your gadget bag. Even these have to be sturdy, which means that when the camera is mounted on it, it shouldn't wiggle at all. This calls for legs that are wide-spread enough for balance, with a ball-and-socket joint that locks rigid.

Tripod-less exposures of longer than 1/30th of a second are possible, but they take great care. You must hold the camera with its base pressed firmly against a sturdy support such as a wall, a door frame, a street-light pole or even a tree-trunk. And for added steadiness, don't push the shutter-release button down with the job of a finger but with the soft release action of a cable release or the self-timer will work on most models down to one second. For longer B (bulb) exposures, use a cable release.

The ideal compromise is to take a tabletop tripod on trips and use it on top tripod on trips and use it on top of ledges and tables and hold it against the sides of doorways and trees. The table-top tripod can also be converted to a chest pod by resting the opened-up legs against your chest to steady hand-held long exposures.

On occasion even as a pro I have been caught without a tripod. Once, in a Pakistani bazaar where I didn't want to attract attention by lugging around a tripod, I improvised for picturing a fire-light scene by holding my Leica pressed against the wheel of a bullock cart and squeezing off up to one-second exposures -- and they were publication quality.

My final observation on whether to tripod or not to tripod is that no matter how careful your planning, you'll find yourself once in a while up the photographic creek without a tripod -- in which case improvise and use one of the methods described.