What’s new Cameras, film & technique A Non-Silver Manual: Instructions for Copy Cameras

A Non-Silver Manual: Instructions for Copy Cameras

Writers / Sarah van Keuren, Sandra C. Davis & Stuart Goldstein

The chapter called “Instructions for Copy Cameras” of Sarah Van Keuren’s book “A Non-Silver Manual: Cyanotype, Vandyke Brown, Palladium & Gum Bichromate with instructions for making light-resists including pinhole photography”, written by Sarah van Keuren, Sandra C. Davis & Stuart Goldstein.

Read the previous section of this book.

A copy camera is essentially a large view camera in a fixed horizontal or vertical position. Historically it has been used to produce negatives to contact print onto offset lithography plates. Continuous-tone images were broken down into dot patterns with halftone screens to satisfy the full ink/no ink requirement of that means of printing. Those of us who work in non-silver who play with such a dinosaur use it as view camera, enlarger and scanner. In our new facility at UArts we inherited a horizontal Brown copy camera that is about 16 feet long with the film end in a small silver darkroom. No charts or manual came with the camera so we are feeling our way regarding f/stops and exposure times for lith film in various enlargements or reductions. So far we’ve had wonderful results, especially with life-size portraits that have a strong presence.

Chemicals to Process Your Film

Before you expose your film, check the sink in the little silver darkroom to make sure that the chemicals you need to process it have been mixed.

If the chemicals aren’t mixed during class time, you can either ask the T.A. or teacher to do this for you or you could mix the chemicals yourself. (Directions are taped to the shelf on which the chemical containers rest). If you mix fresh chemicals, note the time and date that you mixed them on the sheet that’s to the left of the chemical trays.

If the chemicals are already mixed and in the trays, check the sheet on the wall to see when they were mixed. If it was over 3 hours ago, test the chemicals as described below.

Testing to See if the Chemicals Are Still Good

Testing the Developer and Stop Bath

Turn on the exhaust fan and remove tray lids. If the developer is brown, you should discard it and mix a fresh tray of developer. If it is yellowish-tan it is worth testing. If Sprint stop bath has turned purple it is expired and should be discarded. Other stop baths may not have such an indicator.

Under the red safelights, take a scrap of film from the batch you are using, close the film box, and expose the scrap for a few seconds to white light. Agitate it in the paper developer for 1-2 minutes wearing sheer disposable gloves. Then agitate the film in the stop bath for 30 seconds and, through the gloves, feel if it is as slippery as it felt when you removed it from the developer, or if it now feels squeaky-clean. Skip the fixer (since there is no unexposed silver to remove) and rinse the scrap in the wash tray. Holding it over a drip tray, take the film out of the wash and position it between yourself and a white light source. The film should be fairly opaque. If looking through it is like looking through sunglasses, the developer is old and it needs to be replenished or replaced. You can replenish it with two to four ounces of print developer concentrate. If the film felt slippery after its immersion in the stop bath, the stop bath may need replenishment also.

Testing the Fixer

If the fixer smells sulfurous or looks murky, recycle the fixer by pouring it into a white silver recovery unit at the right end of the sink and mix a fresh batch. Otherwise, under the red safelights, again take a scrap of unexposed film from your film source. Make sure the film box is closed, and then turn on the white light. Slip the film directly into the fixer. You have fogged the scrap of film but, because you have not developed it, the silver salts have not turned into metallic silver and can still be dissolved out in fixer. Leave the film in the fixer for a minute. If the film has not completely cleared in that time period, the fixer may need to be replenished with 3 or 4 ounces of fixer concentrate.

Reproduction Percentages

If you wish to have a negative the same size as your original copy material, you will be copying it at 100% and will set both the copy stand and the length of the bellows at 100%. If you wish to reduce or enlarge the negative, the percentage of reduction or enlargement must be determined. To do this, you measure the longer side of the material you want to copy and decide how long you want to make it on the negative. For instance, if the longer side of the image is 5″ and you want the longer side of the negative to be 7″, you’ll need to know at what percentage to set copy and lens to accomplish this enlargement. A pair of rotating disks that should be tacked to the wall in the silver darkroom, called a proportional scale, will conveniently calculate the percentage. You will notice that there’s an inner circle of inches and an outer circle of inches. The inner circle indicates the length of the original (5 inches) and the outer circle the length of the negative (7 inches). Align the inner and outer numbers so that the original’s length is directly under the length intended for the negative. Your reproduction percentage (140%) appears in a window on the scale with an arrow pointing at it.

Preparing the Copy Camera

Glass

Dust and streaks and scratches on the plate glass that covers the copy will show up on your negative. With the room lights on, clean the glass—on both sides if necessary—with glass spray applied to paper towels. Doing this in the beginning will save time, film and aggravation.
Now place your dust free-image under the glass in the center of the copy area. If you want to use a paper grayscale, place it under the glass as well.

Lights

Take a look at the quartz lights on the copy camera before turning on ‘power’. For flat copy work, the 4 lamps should be at 45º angles to the copy. Use the protractor-like angle measurements to confirm the angles, carefully loosening and tightening the controls. By eye evenly space the 4 lamps above and below the copy, again loosening and tightening controls, never forcing.

If you want to backlight translucent copy, remove the black foam ‘target’ from the copy camera’s board and replace it with translucent copy and a film grayscale if desired. Loosen and swing the 4 lights so they are behind the copy at 45% angles above and below the copy.

Positioning Copy and Lens

Copy and Lens Percentages Agree

Set both the copy board and the lens positions to the percentage that you calculated. Unfortunately it is no longer possible to do this from within the silver darkroom. Instead you will need to do it manually by releasing the lock on the bellows, moving it so that a marker is aligned below with the desired enlargement, 140% in this case, and locking it in place. Do the same for the copy, setting it for 140% also. Never force movement with the camera. Always search for ways to unloosen and tighten controls.

When making copy camera negatives of people or other 3D matter, compensate for the depth of the subject by moving back the copy board so that the part of the subject you desire to have in focus is where the copy board was. Have your subject lean her head against the board for stability. A cloth can be draped over the board as a backdrop. To gain more depth of field shut down the lens, doubling exposure time for every f/stop.

Fine Tune Focus with Loupe

To fine tune your focus, open the vacuum back away from the camera in the silver darkroom, gently lower the frosted focusing glass and place a loupe or some other magnifier on the glass. Turn on the quartz lights and see if the subject is in focus. If not move the copy board or the 3-D subject forward or backward until it is in focus, remembering to lock and unlock the bellows or copy board.

If you want to move the subject’s image slightly up and down or side-to-side you can push the red buttons like channel or volume controls on a remote. You can note where the image falls on the ground glass and place white artist tape on the corresponding measurements on the vacuum back so you know where to place your film.

Making Your Exposure

Now that you’ve focused your image, you have to close down the lens for the proper exposure. For flat copy f/11 is a good choice. For 3D copy a smaller f/stop would be better. Recommended exposure times for various f/stops are in the process of being determined but are in a range from maybe 15 seconds to 2 minutes. Results of experimentation will be posted as they are arrived at.

With the door to the silver darkroom closed and only the red safelights on, take out a test strip of the film you will be using and make a test exposure by turning on the vacuum motor and placing the film with the dark glossy side against the vacuum and the dull light emulsion side positioned to receive the exposure when you raise the frosted glass and close the vacuum door.

Make sure you have put away any film that you’re not using for this exposure (otherwise it will be ruined). Now you’re ready.

Shout ‘LIGHTS!’ and press the start button. The exposure lights will go on and the copy camera should automatically turn off the lights at the end of the time you set, but count seconds to make sure it is cutting off when it should. Grab an edge of the film and step on the vacuum pedal to turn off the vacuum.

Processing Your Film

Set the darkroom clock for 2 minutes and quickly slip your film, emulsion side up, into the developer. Rock the tray to cover the surface of the film with developer immediately. If only part of the film is covered in the first few seconds there will be a pronounced ‘lap mark’ around the area that didn’t get covered.

Properly exposed lith film should take between 1 and 2 minutes to develop in diluted paper developer. After the first minute watch the film carefully and be poised to take it out The film can go too dark very quickly and will continue to darken while draining. It is important to drain this film by two corners so that the developer curtains evenly and doesn’t leave streaks, especially in gray areas. Use lith developer for the highest contrast. Print developer in its normal dilution gives high contrast with a bit more gradation between clear and opaque. To approximate continuous tone, dilute paper developer (1:27 or so, instead of 1:9).

Agitate film in the stop bath for 30 seconds and fix for 2 minutes (or for twice the time it takes the film to clear).

Wash the film briefly while you clean the.wet light table by the copy camera. Place a drip tray under the negative and on the light table check the negative for any problems.

Once you’ve checked your negative, no matter how bad it is, put it back in the wash (make sure the tray siphon is operating) for about 5 minutes with the temperature between 70 and 80 degrees Fahrenheit. The closer to 80˚ the water is, the faster fixer washes off the film but the tenderer the emulsion becomes. Don’t let it get scratched by the corners of other negatives or by your fingernails. It is a good idea to finish washing the negative by spraying it with water at a 45 degree angle to remove any gritty sediment from the Philadelphia water. Hang your negative to drip on the line above the sink. Never throw away film. You or somebody else might intensify or reduce it, and scratch or paint or collage it to create a new unimagined work of art. Also, it helps your teacher understand what is causing a problem to see the failed negative instead of hearing that you threw it in the trash…

If you are in a hurry you can dry your film in the film drying locker. Please be sure to turn it off immediately after use since it could overheat (and consumes a lot of power). Don’t lay lith film on drying racks since it may pick up contamination and the imprint of the screening. Don’t let sheets of film dry touching each other. The emulsion is sticky and will rip off if it dries against another sheet of film.

Consider yourself lucky to be able to use the copy camera and the orthochromatic silver darkroom — with the safelights off it is also the only remaining panchromatic darkroom at UArts for tray processing. With the I-lab and a computer lab on the same floor we have the old and the new, the analog and the digital in fertile proximity so that students can experience both modalities and compare results.

Read the next section of the book.

Leave a Reply

WordPress SEO fine-tune by Meta SEO Pack from Poradnik Webmastera