Photography Lab

Lab 11: Photography (I) Taking a Picture – Proper Exposure Film Sensitivity – ISO F-Number (F-Stop) Shutter and Exposure Time Light Meters Choice of Exposure Time vs. F-Number Take a Picture and Develop the Film

Lab 12: Photography (II) Making an Enlargement The Enlarger Photographic Paper Exposing a Test Strip Developing the Test Strips Making the Enlargement

Lab 11 & 12: Precautions Lighting units are equipped with unprotected halogen lamps Do NOT touch the bulbs at all times Avoid prolonged skin contact with the developer chemicals Use tongs to minimize the exposure Wash your hands after you are done with developing films and prints

Processes and Timeline Take pictures with proper exposure on film 20 ~ 30 min (lab) Develop and fix negative image on film 20 ~ 30 min (dark room) Dry film / Write up Make enlargements of negative images 20 ~ 30 min (dark rooms with enlargers)

What do we look for? Good picture (for us) planes of focus on right objects proper exposure of film & photographic paper right amount of light illuminates film or photographic paper for right amount of time

Proper Exposure Film needs proper illumination, I amount of light on film = I amount of light controlled by f-stop, f/ exposure time, T L: amount of light reflected by the object being photographed and transmitted by the camera lens.

Film Speed f/ Exposure Time Basic Concepts Film Speed f/ Exposure Time

Camera Iris aperture Shutter Film Lens f/ Exposure Time

Film Sensitivity (ISO) 50 100 200 400 800 1600 3200 2  more sensitive 22 = 4  more sensitive 222 = 8  more sensitive Slower Film Needs Lots of Light Higher Resolution smaller ISO Faster Film Needs Less Light Lower Resolution larger ISO

Films 4"  5" Orthochromatic films Insensitive to red light ISO 40 ~ 80 (Tungsten ~ daylight) 4"  5"

F-Number (F-Stop) D = 2 cm D = 1 cm Diameter A =  cm2 A = /4 cm2 A/4 f: focal length of lens D: diameter of aperture D = 2 cm D = 1 cm Diameter A =  cm2 A = /4 cm2 A/4 4  less light f/8 f/4 Example: 2  f/

F-Number (F-Stop) 1 1.4 2 2.8 4 5.6 8 11 16 22 32 smaller f/ larger f/ 2  less light 4  less light 8  less light smaller f/ Larger Aperture More Light Smaller Depth of Field Smaller Aperture Less Light Larger Depth of Field larger f/

2  less light on film for the same aperture size Exposure Time 1 sec 2  shorter 1/2 sec 2  less light on film for the same aperture size

Exposure Time Numbers on camera 2  less light 4  less light Units: second Numbers on camera 2  less light 4  less light 8  less light Longer Exposure Time Slower Shutter Speed Slower or Stationary Object Passes More Light Faster Shutter Speed Captures Action Passes Less Light Shorter Exposure Time

Taking Picture

Take Picture – Proper Exposure Important parameters Film Sensitivity (in our case: ISO 40) f/ (Depth of Field) Exposure Time (Object Motion) Light meter determines the proper combination of f/ and exposure time

Inverse of "Exposure Time" Using Light Meter Inverse of "Exposure Time" f-number ISO button Diffuser Set ISO and exposure time Measure ambient light near object Slide the diffuser over until the photodetector is covered Control illumination using the lighting units Measure direct light from object With the exposed photodetector surface normal toward object At close distance from the object Near the camera lens If both are similar, use the settings read near the camera lens If not, good luck... or add more lighting as needed Read f/ Change to desired f/ or exposure time

Film Cassette Load 4"  5" sheet film Double sided Load in total darkness or under indirect KODAK 1A filtered safelight Emulsion side facing “dark slide” Double sided Load up to two films on one cassette Emulsion Side flip open Use reverse side of dark slide to indicate the film is exposed to light Black Strip for exposed film dark slide White strip for unexposed film 45 Film Holder by Fidelity manufacturing company, Sun Valley Ca.

Using Camera Arrange object Use light meter Setup camera Load cassette Open shutter Set the smallest f/ Focus better on subject Focus image on ground-glass plate Set f/ & exposure time Arrange perfect picture Close shutter Load cassette Insert cassette Remove dark slide on the object side Take picture Unload cassette Flip and replace dark slide cover Lock dark slides Image retrieved on April 23, 2005 from http://perso.wanadoo.fr/jacques.labarre/appphots/graflex.jpg.

Developing Negatives

Develop Negatives Developer Stop bath Fixer Wash 1 Wash 2 (aide) Chemical reaction precipitates silver on film – creates contrast Removes emulsion Stop bath Stops chemical reaction on developing film Fixer Makes the developed image permanent Wash 1 Rinses off most of excess chemicals (running water) Wash 2 (aide) Accelerates removal of residual Fixer solution (Permawash) Wash 3 (aide) Rinses off any excess chemicals (running water), or Promotes faster drying (Photo-Flo, standing water)

Film Developing Trays film goes through all trays in the order Developer ~ 5 min Stop Bath ~ 30 sec Fixer ~ 4 min Wash 1 Wash 2 Wash 3 ~ 1 min share with print development

Making Enlargements

Enlarger Beseler 45 MXT Two interchangeable lenses Light Source Condenser Negative Enlarging Lens & Aperture Photographic Paper o i Beseler 45 MXT Two interchangeable lenses ƒ/5.6 to 32 ( for ƒ = 135mm) ƒ/4 to 22 (for ƒ = 80mm) Three independent controls for i, o and focus (both i, o) To change magnification, M=i/o o + i = 80 cm max. Image taken from Beseler web site.

Making an Enlargement Make test strips Expose paper Develop print Measure proper exposure time for your film-paper combination Expose paper Use full exposure time Develop print Go through print developing trays

Make Test Strips Measure proper exposure time for particular film & paper combination e.g. 2~4 sec with f/5.6 Focus using the smallest f/ (largest aperture diameter) This gives the brightest light and the smallest depth of focus If possible, expose with the largest f/ (smallest aperture diameter) The exposure time must be long enough for the light bulb to reach the maximum temperature for the full intensity 8"  10" 4~6 test strips 4.5 s 4.0 s 3.5 s 3.0 s 2.5 s 2.0 s 1.5 s

Develop Prints Developer Stop bath Fixer Wash 1 Wash 2 (aide) stops chemical reaction on developing paper Fixer makes the developed print permanent Wash 1 rinses off most of excess chemicals (running water) Wash 2 (aide) accelerates removal of residual Fixer solution (Permawash) Wash 3 (aide) rinses off any excess chemicals (running water), or promotes faster drying (Phot-Flo, standing water)

Print Developing Trays paper goes through all trays in the order Developer ~ 1 min Stop Bath ~ 10 sec Fixer ~ 2 min Wash 1 ~ 30 sec Wash 2 Wash 3 share with film development

Lab 11 & 12: Notes Demonstrate Using Camera (slide) part to students Use the demo cartridge loaded with exposed film on two sides Apply the basic concepts – illumination, focal plane, ISO number, exposure time and ƒ/ – introduced in lecture