This sheet outlines the procedures for developing film and prints in the ChEMS department darkroom. Before outlining the specific procedures, it is important to make a few general notes.

The darkroom is not a hallway!

The quality of your photographic work is directly related to cleanliness. Dust (especially from spilled fixer) on a negative will result in spots on a print. Because of this it is essential to keep the darkroom clean. It is especially important to clean up spills as they occur. Darkroom chemicals often appear harmless as small drops of moisture, but upon drying they become a white dusty powder. This dust, if left lying on darkroom surfaces will get into the air and redeposit on negatives and lenses. Thus it is important to make sure spills and chemical drops are cleaned up.

Paper towels are available from the department office.

All darkroom use must be noted on the darkroom sign-up sheet.

The TEM film developing chemicals are for TEM film only!. Do not use any of these chemicals for other types of film. The TEM fixer is not to be used for Polaroid film. Polaroid film contaminates the TEM fixer and makes it unusable for TEM plates.

The sodium vapor safelight is sensitive to restarting. Turn it on once per darkroom session. If others will be using the darkroom after you leave it on. This will increase lamp life.

**Individuals who do not adhere to these rules will lose their darkroom privileges!!!!

TEM plate developing

Please log, on the appropriate sheet, the number of TEM plates you are developing.

It is the responsibility of all of the TEM users to make sure the chemicals are in good shape and to replace them as needed.

Prerequisites:

Check the condition of all chemicals - replace evaporation losses with tap water.

Temperature Regulator: The temperature of the developer is a variable of paramount importance in achieving uniform (or even useful) results. Turn on the flow control (upper knob) only. It may take a minute or so for the delivery lines to come to temperature. The temperature and flow control knobs require no adjustment.

Developer: Should be relatively colorless ("tea" color or lighter) and clear. Change after 200 plates or 2 weeks. Made up of 1.5L D-19 stock + 3.0L tap water. Developer is oxygen labile; keep covered when not in use

Rapid fixer: Should be clear. Replace when developer is replaced. This solution comes in a 1 gallon kit. Follow enclosed instructions

Hypo clearing agent: Replace when developer is replaced. This solution is also premixed and on in the left side water jacket. Dilute the stock solution 1:4 with tap water.

Photoflo: Should be replaced about every 200 plates. Use two capful plus 3.5L tap water. Keep this covered when not in use.

Procedure:

Always use gloves when handling dry film, cassettes and holders!

1. Turn on developer tank cooling water and allow 10 minutes to equilibrate.
2. Plug in safe light 5 min. prior to further operations.
3. Turn room lights off and red safelight on.
4. Place film in racks - make sure plates do not touch.
5. Place rack of film in developer.
6. Raise and lower gently for 5 seconds to remove bubbles.
7. Repeat shaking 5 sec every 30 sec.
   -avoid side-to-side motion (this may dislodge film from carrier)
   -develop for 4 minutes.
8. Place films in 68^o F running water (next to developer) for 90 seconds.
9. Fix films in rapid fixer for 4 minutes.
10. Rinse film in running water for 60 sec.
11. Clear films for 4 minutes in hypo clearing agent.
12. Wash films in flowing water for 8 minutes.
13. Dip plates in Photoflo solution.
14. Place plate rack in dryer (cover top with unfolded paper towel).
15. Clean up darkroom.

Be sure to collect your plates as soon as possible as we have a limited number of film racks. Do not trust the next user to treat your plates as well as you would. Conversely, if you must remove someone else's negatives from a rack, treat them better than you would your own.

The department can only supply a limited number of glassine envelopes i.e. one envelope fora large number of plates. You should arrange your own system for storing plates.

Photographic Printing

The printing of photographs is done using wet chemicals in trays. You must set up the chemicals at the beginning of your session and clean them up when you are done.

The same processing procedure is followed for both contact printing and enlarging. The most common mistake made when printing is to turn on the lights while the photographic paper is open, resulting in a ruined batch of paper. Please be careful. Have only a small number of papers out at any given time.

The sodium vapor safelight is sensitive to restarting. Turn it on once per darkroom session. If others will be using the darkroom after you leave it on. This will increase lamp life.

Keep all wet processing on the west side of the darkroom (that would be the side with the sink)

Prerequisites:

Developer: 1 part Dektol stock, 2 parts tap water. Note this mixture may be used for 24 hours after dilution. Put your Dektol back in a bottle labeled used/diluted Dektol when your session is finished if others will be printing. Don't confuse stock and working solution bottles.

 

Stop bath: premixed in gallon jug under sink. Use 1 part indicator stop bath, 64 parts tap water. Save this until it turns purple (dark, under safelight illumination)

 

Fixer: premixed in a gallon jug under sink. Test before and after use with one drop of KI solution. If a precipitate persists, fixer is spent. Only use as much fixer as necessary.

Procedure:

1. Expose your print using either the contact printer or enlarger. Contrast can be varied by using the contrast filters in the enlarger (for both contact prints and enlargements) or by using different grades of photographic paper. For TEM work remember to orient your negative such that the resulting print is oriented the same as your diffraction patterns.
2. Develop the print for 1 minute. If the print is under or over exposed, adjust the print time in the enlarger or contact printer, do not adjust the developing time.
3. Stop the print for 5 seconds in the indicator stop bath.
4. Fix the print for 2 minutes in the fixer. The prints are light safe once they are in the fixer, but remember to put away any unexposed paper before turning on the lights.
5. Wash for 4 minutes in the siphon tray. Note: washing too long can result in a breakdown of the print paper and significant curling. If you add subsequent prints from the fixer while prints are washing, start timing the wash anew!
6. Remove the prints and dry them. Note: For resin coated papers (RC), dry them emulsion side (image) up in the paper dryer. Do not attempt to ferrotype or drum-dry resin coated papers.
7. Clean up your chemicals and the darkroom. Remember the Dektol may be reused.