Posted by Moose on June 12, 2003 at 03:16:12:
In Reply to: Focus posted by Frank Covey on June 11, 2003 at 13:55:46:
: I have a Nikon F3 and a 1000mm f11 Nikon Reflex lens' If I set the focusing ring at infinity and look at the Moon it is not sharp. Do I need to have this lens re calibrated ? ( This applies to any other objects at Infinity, or any other selected distance ) I also have other Nikon lenses that focus OK, so its not in the Camera.
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You CANNOT use a mirror lens at infinity and expect everything to be in focus--the depth of field on these lenses is extremely narrow. The mirror lens is a strange beast, that requires fine tuned focusing sometimes beyond infinity, unlike conventional lenses. You just have to work with it until the subject is in focus, regardless of what the lense's distance scale says. But, of course, if it will not focus no matter how much you try, you may have a problem lens or need to get your eyes checked. :)
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