Introduction

Explain to the students that for the first few minutes of the film processing procedure they are going to be working in complete darkness. Explain that the best negatives result from handling film carefully and following processing procedures exactly.

Instruction

Discuss in detail good film processing practice: how to open film rolls, cassettes and cartridges; how to handle film without scratching it or leaving fingerprints (handle film by its edges only); how to load processing tanks; and how to work the timers (see timer instruction manual). Show students how to pour solutions into and out of processing tanks and how to agitate a full tank.

Allow students to practice loading their processing tanks with practice film in normal room lighting. (You can use some fogged or outdated film for this purpose.) Repeat this step with the room lights turned off.

Then have each student load and process the roll of film exposed for Assignment No. 3. When the processing and drying are done, explain and demonstrate how to judge negative quality. Have your students put their negatives into envelopes.

Things That Can Go Wrong

Streaky Negatives -- Due to uneven development. Probably not all of the film was in contact with the developer throughout development time or there simply wasn't enough solution.

Rows of Regularly Spaced Marks -- If they occur inside the picture area of the negative, it's because the film wasn't properly seated in the apron or because you used the wrong apron.

Black Streaks -- A sign that light reached the film while you were loading or unloading your camera. If all the streaks are on the same side, it might be because the top of your developing tank was loosened during processing.

Overall Grayness -- Often caused by light sneaking into your darkroom during the time you were loading your developing tank.

Thin, Very Transparent Negatives -- If there are no really dark black areas in the entire negative, it usually means that your developer was too cold, the developing time was too short, or the negative was underexposed.

Dense, Heavy Negatives -- This indicates that the developer was too warm, the film was developed too long, or the negative was overexposed.

Assignment

Have the students start a negative file.