Safelights

Lighting for the darkroom that doesn't fog prints.

Properly-employed, safelights provide a remarkable amount of illumination in a darkroom, enabling you to see objects, including photo-sensitive paper for making prints without fogging the paper. You will actually be able to see the image appear as it becomes formed on the paper during the development process.

(Please note: Film, most of which is panchromatic - that is, sensitive to all colors of light - is not meant to be viewed under a safelight. No light at all should be used in processing almost all films.)

SAFELIGHT PLACEMENT

Safelights are designed to be used on a countertop or wall-mounted, and some can be hung from the ceiling to provide direct or indirect (bounced off the ceiling or walls) illumination.

When placing a safelight in a darkroom, the objective is to obtain the highest level of safe, overall illumination (which can be surprisingly bright) without risk of fogging the paper.

This means:

• selecting the right color of safelight or safelight filter in accordance with the paper manufacturer's recommendation (usually printed on the package or the paper's data sheet);
• choosing the right strength of light bulb for it;
• placing it in the best location,
• aiming it so that its light shines where you wish it to, and
• maximizing the light-reflectiveness of darkroom surfaces (for example, using high gloss white paint for the walls and ceiling).

WHY DOES A SAFELIGHT NOT FOG THE PAPER USED TO MAKE PRINTS?

The key is in the paper itself, and in correctly matching the paper's photosensitivity range with the color of the light from the safelight. Most papers intended for making photographic prints are made so they are not panchromatic (i.e. not sensitive to all visible colors). They are generally orthochromatic - meaning they are mainly sensitive only to blue and green light, but not to red light. This is why safelights commonly transmit red, orange or brown light.

WHICH ONE SHOULD YOU USE? HOW DO YOU KNOW?

When you purchase paper for printing, the recommended safelight is specified right on the package or in the manufacturer's data sheet included with the package. If you use the manufacturer's specified safelight, ensuring that it is not too close to the paper, you should never have fogged paper and will always have a sufficient amount of illumination to work comfortably while making prints in your darkroom.

HOW CLOSE CAN THE SAFELIGHT BE?

To ensure the highest quality of black-and-white print, you must be confident that your darkroom's safelights are as "safe" as possible and do not cause even minimal fogging. Manufacturers of safelights usually recommend a minimum distance, often around four feet, that the safelight should be kept from photosensitive paper. However, the only way to know for sure what the minimum distance is, is to perform a test.

There are various safelight tests that you can perform, however the following is an easy-to-carry-out test that should reveal most fundamental problems.

Basic safelight testing is simple:

• Position the safelight in accordance with the manufacturer's recommended distance from the area where you will be handling the paper, or even further away if you find that it provides adequate illumination.
• Check that the bulb is of the recommended power.
• With all lights switched off, ensure that no light is leaking into the darkroom, which may take as much as fifteen minutes to allow your eyes to fully adjust to the darkness.

• Turn on your enlarger, and check that no white light is leaking from its sides or top. If there is leakage, be sure to correct the problem before going further.
• With no negative in the enlarger's negative carrier, expose a sheet of print paper as if you were making a normal print, but with the safelight turned off.
• Now, securely cover half the sheet with an opaque material, one that will keep all light from it, and expose the other half to the safelight's illumination at its normal working distance from the safelight, but for a little longer than you might leave the paper in normal processing.
• Develop, fix and rinse the paper as you normally would.
• Now, carefully examine the finished print.
• Check to see if one half is lighter, darker or in any way has more contrast than the other.
• If it does, then the difference had to have been caused by the safelight, telling you that the illumination from it is unsafe for that paper under the same conditions.
• If you are sure that you are using the proper (manufacturer-recommended) safelight for the paper, then you must increase its distance or cut down the lamp's power.
• Do one or the other, then run the same test again until the results are satisfactory - i.e. no noticeable difference between the halves.

SAFELIGHTS ARE NOT "SAFE" OVER AN EXTENDED TIME PERIOD

The light from any safelight will eventually affect photosensitive paper and cause a visible change if the paper is exposed to it for a long time. It is always wise to keep paper protected from a safelight (any light, in fact) until you are ready to use it to make a print.

SAFELIGHTS DETERIORATE WITH AGE AND EXTENDED USAGE

When a safelight is in use over long time periods, such as several hours a day on a regular basis, it will gradually fade and become less reliable. A good precautionary measure is to replace the safelight's filter annually, recording the date of the change so that you can do it again the following year.

CAN I USE MORE THAN ONE SAFELIGHT?

Certainly. One safelight may be all that is needed for a small darkroom, but two or more safelights can be used in larger darkrooms. Each should be matched to the paper employed in making prints and should be individually-tested to ensure it is properly located to prevent fogging.