Stereo Realist Depth of Field Scale (DOF)
Offered for sale here is a Depth of Field scale for your Stereo Realist. Pictured below are the scale for a 2.8 Realist (left, in silver color) or for a 3.5 Realist (right, in black color)
Please specify when ordering
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Installation:
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Set focusing near infinity and remove the focusing indicator/camera strap holder by removing three screws (two are shown, one is at the top, you will have to remove the film advance knob to reach it) Make sure not to lose the strap lug.
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Install DOF scale. Make sure not to move the focusing dial and lose track of which round the focusing is in. Replace screws.
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Note: The focusing indicator might be in a slightly different position in the DOF scale (this is the case in the two Realists shown above). In this case, it is recommended that the focusing is checked and possibly recalibrated, for optimum focusing accuracy. This is not an easy thing to do, but I do it routinely in my Stereo Realist repairs.
Uses of the DOF scale
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For a given focusing distance and f-stop, you can read the depth of field as follows: Find the two f-stop markings in the scale (if the lens aperture is set at f8, look for the two 8 marks in the DOF scale). These mark the depth of field (DOF). DOF is the distance range from the camera that it is in acceptably good focus. This depends on the f-stop. The smaller the f-stop (high numerical values), the larger the DOF.
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For a given f-stop you can find the hyperfocal distance. Again find the two f-stop markings in the DOF scale. Set one at infinity (INF). The focusing pointer points to the hyperfocal distance. By definition, hyperfocal distance is the distance at which infinity is in acceptably good focus. The near DOF distance is equal to half the hyperfocal distance (you can verify this by looking at the distance pointed by the other DOF marking)
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You can use this DOF scale to replace a damaged DOF scale or lug holder. A tip: You can use the right hand lug strap holder on the left side and install the DOF scale on the right side.
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A trick I learned from Charles Piper: You can use the DOF scale to figure out the acceptable depth range for a given focusing distance. For this purpose just use the f8 (liberal) or f5.6 marks of the DOF scale. For example, if the near object is at 5 feet, the f5.6 marks of the DOF scale point to 10 feet. You should restrict the depth range in the scene between 5 and 10 feet (this is the conservative estimate; the liberal estimate obtained at f8 is 18 feet). Note: This depth range recommendation is independent of the f-stop used in the camera. More explanations and details are found in my Stereo Realist book
Also, please check my stereo store or my ebay auctions for price and payment information
Updated: November 2007