Outstanding color slides can be made by photographing a Macintosh Color Monitor display. One of the major problems, until now, has been determining exposure settings. The application,"Neutral Test Window", simplifies this task by using a technique long known to photographers engaged in traditional copy work. Related issues such as the type of slide film needed, lenses, etc. are discussed below under, "HOW TO TAKE A PICTURE FROM THE MONITOR" .
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HOW IT WORKS
Photographic exposure meter readings are based upon the assumption that everything reflects, on average, 18% of the light that strikes it, i.e. everything averages out to a medium dark shade of gray. As a result, when you take a light meter reading from something that is predominantly black or white, the resulting exposure will be incorrect. For example, if you try to copy a white sheet of paper with a small bit of writing on it by taking an exposure reading from its surface, the resulting picture will be gray, not white, since the meter assumed that it was 18% gray and sets the exposure to produce a gray picture.
To avoid this problem, camera stores sell a "Neutral Test Card" (Kodak CAT 152 7795) which is a piece of cardboard with a gray surface that reflects exactly 18% of the light striking it. To copy an object, such as our white sheet of paper with writing on it, one first focuses on the white sheet. A "Neutral Test Card" is then set on top of the white sheet and an exposure reading is taken from the card. The card is removed and the picture is taken based on the "Neutral Test Card" exposure reading. When done this way, whites will come out properly white and blacks, black.
"Neutral Test Window" is the Macintosh computer equivalent of a "Neutral Test Card". It will fill the screen with a random pattern in which 18% of the pixels are white and the rest black. The pattern is intentionally rough so that you have something to focus on. Take your meter reading from the "Neutral Test Window" and use that exposure reading to photograph anything you wish from the monitor screen. This works equally well for black & white (B&W) and color.
This is the heart of "Neutral Test Window" - BUT - there is more involved than good exposure settings when one wishes to create truly wonderful slides &/or pictures from a Macintosh monitor. If you read and use the advice given below life will be good and you will prosper, or at least you will have a better shot at a good picture.
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HOW TO TAKE A PICTURE FROM THE MONITOR
• Select high contrast color or black & white film when possible. Transparency materials that I have tried and like are Kodak Ektachrome 100HC daylight color slide film and Poloroid Polachrome High Contrast Instant Slide film.
Poloroid instant slide film requires the purchase of a special processing box and does not render as sharp an image as Ektachrome.
Remember that color slide film can be used to make black & white slides from a black & white monitor. Color slides have more visual impact and should be used when possible.
• Turn the monitor brightness up to maximum. If you are working with a color monitor turn the contrast up to maximum. You want all you can get.
• Work in a darkened room, or at least have dim lights which do not shine on the monitor. Reflections spoil results and light hitting the monitor will reduce the brilliance of the screen.
• Plan images that use as much of the screen as possible to avoid seeing big pixels, i.e. jagged edges, in the resulting photographic image. The larger the image & monitor, the smoother the resulting photograph will be.
• Remember that your photograph or slide will have a different top to bottom - side to side ratio than the screen has. Plan your images accordingly.
• Use LARGE fat or bold style fonts for text. Bigger is better. Eighteen (18) point should be the smallest used. To avoid scaling distortions and jaggies, only use font sizes that are installed in the system file.
• The camera lens should be on axis with the center of the screen; the screen and camera should be at exact right angles.
• Use a "Macro" lens if possible as this is really close up photography and you want a flat field of focus. The next best choice is a telephoto lens.
• Use a tripod and cable release to prevent blurred images resulting from camera movement during the necessarily long exposures.
• Automatic exposure will not work. You will have to set exposure time and f. stop manually based on the exposure meter reading and considerations listed below.
• If possible close the lens aperture (f. stop) down at least 2 to 3 stops from maximum to achieve an adequate depth of field. For example, if the maximum lens opening is f4.0, use at least f8 or f11. The monitor screen is slightly curved and you want to get it all in focus.
• Exposure length should be 1/30 of a second or slower to avoid seeing a line across the screen as the monitor redraws its image.
• Long exposures (over 1/2 or 1 second) based on meter readings often need to be even longer to be correct. These extra long exposures are refered to as "COMPENSATION FOR RECIPROCITY FAILURE". Read and follow the instructions that come with the film regarding "compensation for reciprocity failure" when a long exposure is used. Recommendations regarding filtration for color can usually be ignored as you are only going to get approximate color fidelity in any case.
• Open (double click) "Neutral Test Window". Focus and frame with the camera positioned to take the actual pictures. Read the exposure time and f. stop from the meter. Remember to use a slow shutter speed and adjust as recommended in "Compensation for reciprocity failure." Quit "Neutral Test Window" but use this exposure setting to take your photographs.
• IMPORTANT: Clean the monitor screen and camera lens.
• Last but not least there are always special conditions which require modification of the exposure recommended by "Neutral Test Window". Experience is your best guide here. For very important images “BRACKET” the exposure by taking extra shots with both increased and decreased exposure.
