Black and White Photography

Hot lights are useful, in large part because of their constant illumination.
Once you turn them on, what you see is pretty much what you get. However,
their high heat makes them dangerous to handle and also potentially uncomfortable
for the subject and the photographer.
To avoid such problems, professional photographers often use strobe lights.
Another name for electronic flash, strobes provide all the light necessary to illuminate
a scene in a fraction of a second. You probably are familiar with oncamera
strobes, which are lightweight, portable, and offer a high degree of
automation. Studio strobes are much more powerful and often have a separate
battery pack unit to help provide that power. One disadvantage of strobes is
that their brief burst of light means you can’t see their effect when they go off.
Good studio strobes, however, have a built-in modeling light, a relatively lowpowered
lamp for previewing the lighting.
The most commonly used type of artificial lighting is electronic flash. Most of
the time, flash is used in low-light situations when you otherwise don’t have
enough light to get a good exposure. Other uses of flash include freezing the
motion of a subject and lowering contrast, such as might occur on a bright,
sunny day, by lightening dark shadow areas.
Electronic flash is linked to your camera’s shutter. When you press the shutter
button, a gas-filled tube inside the flash emits a powerful burst of light for a
very short time, often 1/5000 or even shorter. A reflector behind the tube helps
direct the light forward toward the subject.
Many cameras have an electronic flash built in, but most cameras need a
separate unit. Called on-camera flash, these units slide into a bracket, called a
shoe, located on top of the camera. A shoe often provides an electrical connection
to the shutter and is thus called a hot shoe. But if your shoe is not hot, or
if you use the flash off-camera, you need to use a cable, sometimes called a pc
or synch (for synchronization) cord to connect flash and shutter.
Flash types. There are many flash models available, but almost all can be generally
classified as follows: TTL autoflash, non-TTL autoflash, and manual.
TTL (through-the-lens) autoflash units are part of a dedicated camera system
and measure light as it’s about to strike the film. They are designed to work
seamlessly with a camera’s meter to provide a high degree of automation,
precise exposure, and a variety of advanced options.
Non-TTL autoflash units offer some automated features, but their lightmeasuring
sensor is on the flash unit, rather than inside the camera. This means
non-TTL autoflash is not fully integrated with the camera’s exposure system, so
its operation is not as seamless or precise as TTL flash units.

Manual flash models are available, and there is a manual mode option on

most TTL and non-TTL autoflashes. With these units you have to calculate

exposure and settings yourself.

Flash synch. When a flash burst goes off, the shutter must open to completely

expose the film; in other words, it must synchronize (“synch”) with the flash. If

it doesn’t synch, the shutter may only be partially open when the flash fires,

resulting in a negative that is only partly exposed.

Cameras with a leaf shutter, which includes most non-SLR (single-lensreflex)

models, synch with flash at any shutter speed. But because they use a

focal-plane shutter, SLR cameras are more limited. With most SLRs, the maximum

synch speed is 1/60 or 1/125, though some models synch at other shutter

speeds, such as 1/250. You can set a slower shutter speed, such as 1/15 or 1/30,

for flash synch, but you cannot set a faster speed, such as 1/1000.

In many camera models the maximum synch speed is highlighted in color or

indicated by a flash symbol on the shutter dial or in the camera’s LCD display.

You don’t really have to worry about the synch speed if you are using a TTL

flash on an automatic setting, because the camera sets the shutter speed for

you. But with a non-TTL autoflash or when using a manual flash or manual

mode, double-check to make sure your shutter speed is set correctly before

photographing.

Exposing with Flash

Exposing film with flash is somewhat different than exposing without flash.

With flash, you must consider the following factors: flash output, flash-tosubject

distance, lens aperture, and film speed.

Flash output includes the power of the flash (the strength of the light it

provides), as well as the duration of the flash (how long the burst of light lasts).

TTL and non-TTL autoflash units vary their flash output to accommodate

different lighting and exposure situations, whereas manual flash provides a

constant burst of light every time it goes off.

Flash-to-subject distance has to do with how far that flash is from the

subject. When it’s close to your subject, it will have a stronger effect than when

it’s farther away. This is because flash light diminishes in strength as it travels

over distance, just like any light source.

A lens aperture set at a large f-stop provides more film exposure than a lens

aperture set at a small f-stop. So, if the flash output is strong or the flash is close

to the subject, you will need a smaller f-stop than when the output is weak

and/or the flash is farther away.

The faster the film speed, the less flash output you need for good exposure,

because fast films need less light than slow films. Faster films also allow you to