- Load the film holders in the dark. (three wooden objects in back of the camera above) This could be done in a dark room or in a folding table top tent that you slid your arms into. The photographer had to make sure that the emulsion was facing outwards. A dark slide protected the plate from exposure when not being used.
- Set up the camera on a tripod and position in front of the subject.
- Open the lens to allow light to come through. Open the aperture blades all the way so the image will be visible.
- Drape a black cloth over your head and look at the ground glass on the back of the camera. The faint image will appear upside down and backwards.
- Adjust the focus. The front standard which the lens is mounted on moves forward and back on a geared track. The closer the camera is to the subject the more bellows will be extended.
- Determine the exposure. I am going to take some educated guesses at this. First the plates had an estimated light sensitive or ASA speed of 10. As a rule of thumb on a sunny day at an f stop of 16 the shutter speed would be the same as the ASA. Most of Kinney's plant pictures are inside with bright diffused natural light. Not as bright as a sunny day though. So as a start I would say f5.6 at 1/10. Next you have to determine how much extra time needs to be given for the long extension for close up work. Refering to a chart like the one below, I would estimate at least a 10x exposure factor depending on the lens used and how much bellows were extended. This now puts us at f5.6 at 1 sec.
Thursday, January 30, 2014
Side Tracked by Botany
First of all, I do not know what camera or cameras Kinney used. I do know that the images were primarily 5"x7" glass plates. I am guessing something like an Eastman wooden view camera.
This particular one is an 8"x10" but it shows the extension rail that Kinney would have needed for his close up plant work. To get an idea of what it was like to use a camera like this, especially for the close up roots shot, I'll go over some of the shooting process.
The aperture f5.6 is too open for good detail in a close up image with a large format camera. Kinney would have to stop down to a smaller opening such as f16. This would increase his exposure. f8 @ 2 seconds, f11 @ 4 seconds, and finally f16 at 8 seconds. Now reciprocity failure of film comes into play.
This chart gives you an idea of how the sensitivity of film falls off with longer exposure times. I would guess that Kinney would have to double the time giving a final exposure of f16 at 16 seconds.
8. These long exposure times needed great care while shooting. The slightest movement of the camera or subject for 16 seconds would result in a soft or blurry image. A truck driving by or a slamming of a door could result in a ruined image.
9. I am amazed that Kinney did not bracket his images very much. I do not see many over or under exposed plates. He may have only kept the good exposures.
10. Finally the lens was closed and stopped down to the correct aperture. The shutter speed was set and the lens was cocked. The film holder was placed in the back of the camera and the dark slide was pulled. A cable release was attached to the shutter and depressed to make the exposure.
The dark slide was then slid back in place indicating that the emulsion was exposed and the the holder was flipped to the other side to allow for another exposure.
Next it was off to the darkroom for processing. This process was done in complete darkness for any where from 10 - 20 minute developing times, depending on chemistry. The plates were probably hung on stainless steel carries and then submerged into the developing bath. Due to the consistency of Kinney's negatives, I think that he had a system down. One type of film with one type of developer, and not much experimentation.
Technical aspects aside Kinney's plant images have a simple quietness to them. Even before working on this project, I have always enjoyed taking a walk down to the Mount Holyoke Talcott Greenhouse. Especially in the dead of winter, the warm sunlit rooms seem to fill the frame with endless compositions. I can only imagine on top of that feeling, to know that the plant on the glass was something that you nurtured and grew.
Here are a few of my own images from the Talcott.