Basic Darkroom Procedures

Photographic Paper

Your photo kit includes a pack of 8 x 10 inch photo paper.  It comes in a resealable opaque plastic pouch.  NEVER OPEN YOUR PHOTO PAPER EXCEPT IN THE DARKROOM!!!

Why?  Because it’s photo-sensitive, meaning it reacts to light.  It contains silver salts such as silver nitrate, which darkens after exposure to light, when immersed in developer solution.  Click the link to learn more about silver chemistry.

There are many useful ways to expose photo paper to light:

  1. Usually you use an enlarger, which lets you shine a light through a film negative.  You focus this light on photo paper, and the dark areas of the negative let less light through.  When you develop the paper, the dark areas of the negative become the light areas on the paper, so you get a positive print.
  2. Sometimes you place a bunch of negatives directly on the paper, and when you expose it to light and develop it, you have a positive contact sheet.
  3. You can also expose the paper directly to light inside a pinhole camera, in which case you end up with a negative image on the paper.
  4. And you can just place objects on the paper and expose it, creating a photogram.

Using an Enlarger

An enlarger is used to focus light onto photo paper, usually through a negative, thereby exposing it.  Enlargers consist of a light source shining down through a condenser lens and a negative holder.  The projected light is focused on the base, where you place your photo paper in an easel for exposure to the light.  There’s usually a timer on the light, and an adjustable aperture so you can vary the exposure time and strength of the light.  You can also move the light up & down to change the size, and adjust the focus with a knob.

For a photogram, you simply place your paper in an easel on the base, arrange your objects, and then turn on the light for a predetermined period.

Developing Exposed Photographic Paper

This is the chemical process used to make the exposed image on the paper visible, and stop it from turning any darker.  The steps are:

  1. Immerse the paper in the developer bath, using tongs.  In our darkroom this should always be the leftmost tray.  Gently agitate the solution for about 60 seconds.  You should see your invisible latent image become visible in the dim safelight – magic!  Then pick it up with the tongs, and let it drip for a couple of seconds.

The developer is a chemical that makes the exposed parts of the paper dark (visible).  Unexposed areas stay white.

  1. Drop the paper in the stop bath, to the right of the developer tray, again using tongs.  Leave it there for another 60 seconds.

The stop bath stops the development process – otherwise your picture would gradually get darker.

  1. Take the paper to the Fixer bath for 3 to 5 minutes. This removes unexposed silver nitrate from the paper and freezes the image as you see it.
  2. Rinse the fixer off for 5 to10 minutes in the flowing water bath.
  3. Squeegee the excess water off (into the sink).  Hang to dry
  4. CLEAN UP any mess or spills you might have made!

Test Strips

How do you know how long to expose the paper in the enlarger for, and at what F-stop (how large an aperture)?  The answer is “you don’t”!  But you can find out by experimenting with test strips.  Here’s what I mean:

  1. In the darkroom, cut a full sheet of your photo paper into strips about 2” x 8” – you should get about 5 from a full sheet.  You can cut these in half if you need a smaller cheaper test strip.  Keep the unexposed ones sealed in your envelope.
  2. If you’re doing a photogram, adjust the aperture to its darkest setting.  Then expose one small strip, with an object on part of it, for 2 seconds.  Do the same with another for 4 seconds, and others at 8 and 16 seconds.  Keep track of what the exposure time and F-stop was.
  3. If you’re doing a normal negative, place the strip under a representative part of the image.  Set the timer for 40 seconds.  Cover ¾ of the strip with an opaque object.  Expose for 20 seconds.  Move the cover to expose half of the strip and expose for another 10 seconds.  Move to uncover ¾ and expose for another 5 seconds.  Remove the cover and expose for a final 5 seconds.

This gives you pieces of the strip exposed for various times:  5 seconds (the last area exposed), 5 + 5 = 10 seconds for the 2nd last area, and 20 and 40 seconds for the first 2 areas.  Feel free to vary these times to suit your purposes.

  1. Develop the strip(s) normally.
  2. Once they’re fixed, give them a quick rinse and take them out into the classroom light.  Decide what the ideal exposure time is based on what you see.  It might be a time in between one of the exposures you tried.