Camera, Lens & Film

This page is a collection of useful files, all concerned with the process of image capture, depth of field, sharpness, resolution and proper film exposure. A more in-depth description of most techniques can be found in the first and second edition of 'Way Beyond Monochrome'.
USAF/1951 Test Pattern  USAF/1951 Resolution Chart You can use the test pattern to check the performance of your photographic lenses. The results don't replace an MTF graph, but the test is simple to do and gives a good indication of lens performance.
Mount camera and lens onto a tripod, and use a fine-grain film to take a photograph of the test pattern from a distance equal to a known multiple of the focal length (25-100x). Consider the use of a cable release and flash photography to reduce camera-shake as much as possible. Inspect the negative with a loupe and find the group and element where you can still make out a line pattern. Identify the accompanying resolution of the test pattern in the resolution chart, and multiply that value by the focal-length multiplier, used above, to find the actual lens resolution in line pairs per millimeter (lp/mm).
Example: You photographed the test pattern with your 50mm lens from a distance of 2,5 m (50x). After developing the film and evaluating it with a loupe, you can just about separate the lines in the 2nd element of group '0'. Reading the resolution of that element from the resolution chart (1.12) and multiplying that number with the distance multiplier (50) used, you can conclude a lens resolution of approximately 56 lp/mm for this 50mm lens. Depth-of-Focus Ruler These depth-of-focus rulers (scale and gauges) are based on a standard circle of confusion appropriate for 4x5, 5x7, 8x10 and 11x14-inch view cameras. The rulers can be used with any lens, because they are independent of focal length. Print a copy of the scale, and the gauge fitting your camera format, for your personal use. Mount the scale to your camera, identify the standard's position of near and far focus, and use the gauge to translate the distance between the two into the required aperture. Then, move the focusing standard to the optimum focusing position, which is midway between the markings for near and far focus. This way, depth of field will be achieved between the near and far focal planes. Film Exposure This is a table of my favorite films and their speeds for subject brightness ranges from N-3 to N+3. The corresponding development times are listed in the file ‘Film Development’ in the ‘Darkroom Library’. Depending on your equipment and technique, these values may change. Consequently, they are only offered as a starting point for your own evaluations.
Zone Dial With only two disks required, the Zone Dial provides a visual reference to the way subject brightness will be represented in the final print. Zone III and VII are marked to place shadow and highlight details, and the tonality extremes of Zone I•5 and VIII•5 are identified as black and white points. All scales are in standard shutter speeds, f/stops and EVs. Meter the subject values in EVs, and correlate them to the intended Zones on the dial. This will give you an overview of the subject brightness range and several exposure recommendations.

Pentax Spotmeter Pentax Digital Spotmeter A customized zone dial for the older Pentax Spotmeter and the newer Pentax Digital Spotmeter serve as a visual reference and will simplify zone placement. Zone III and VII are marked to place shadow and highlight details. I suggest you print the appropriate scale onto a self-adhesive label, cover it with clear tape before cutting it to size, and then affix it to the Pentax Spotmeter by aligning the notch with the white arrow on the meter and tape it to the Pentax Digital Spotmeter by centering it just below the EV scale. Bellows Target & Ruler View camera owners, print the target and the ruler on your own printer. Laminate each piece with clear tape to make a more durable tool. For close-up photography, place the target into the scene, and measure the diameter of the circle on the view screen with the ruler. Determine subject magnification and f/stop correction to adjust exposure by opening lens aperture or extend shutter exposure.

Convert EV to Photometric Values Many lightmeters are not able to measure the photometric values for lumination [cd/m2] or illumination [lux] directly. However, many can measure both values in terms of EV, and of course, all can measure the aperture and shutter speed required for proper exposure. This little spreadsheet converts typical photographic measurements into photometric values, as long as the calibration constant for the lightmeter is known.
The calibration constant can be obtained from the manual or directly from the manufacturer. If the lightmeter is able to measure and display both, EV and photometric values, the spreadsheet can calculate them for you. If you are not able to determine your lightmeter’s calibration constant, assume the following constants for ‘reflective’ or luminance meters: Gossen (K=11.5), Canon, Nikon, Sekonic (K=12.5), Minolta, Pentax (K=14), and assume a calibration constant of C=250 for all incident meters with flat receptors.

Pinhole Dial With only two disks required, the Pinhole Dial provides a visual reference to the way subject brightness will be represented in the pinhole print. Zone III and VII are marked to place shadow and highlight details, and the tonality extremes of Zone I•5 and VIII•5 are identiﬁed as black and white points. All scales are in standard shutter speeds, f/stops and EVs. Meter the subject values in EVs, and correlate them to the intended Zones on the dial. This will give you an overview of the subject brightness range and several exposure recommendations.

Reciprocity Compensation This reciprocity compensation table provides exposure and development suggestions for tabular grain TMax films and conventional film types. The contrast changes are based on theoretical values and must be verified by individual tests. Make yourself a copy and keep it in the camera bag as a reference.