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The distance your camera should be positioned from the SpyderLENSCAL is 25-50 times
the focal length of the lens. For instance, if you need to calibrate a 50mm lens you
should place your camera 1250-2500 millimeters from the SpyderLENSCAL. 1250-
2500mm is 125-250 centimeters or about 49-98 inches. Below is a table of common
focal lengths and suggested distances.
Turn on your camera and set the exposure mode to Manual or Aperture Priority. Select
the lowest native ISO, turn off the lens stabilizing function (if the lens has it) and set the
lens to its widest aperture. If you are calibrating a zoom lens, set it to its longest focal
length. Some cameras will allow you to adjust a lens at multiple points in the focal
range. If your camera has this functionality, adjust at each of the suggested focal lengths
for the lens you are using.
You can also use a flash on camera or off camera to illuminate the side with the ruler
guide.
