I have a 'Microsight' grain focuser, inside of which is a thin wire strecthed across the field of view. The eye piece is 'screw focus' adjusted to the wire sharply in order to 'calibrate' the focuser before use.
Well, the little wire has come out, and I'm not positive where in the inner assembly it's proper positioning in order to re-install.
Working without the wire, my intent was to 'calibrate' the grain focuser empirically using a pre-focused negative with from the enlarger onto the baseboard, and then viewing this prefocused image through the grain focuser while 'focusing' the eyepiece of the grain focuser until that image was sharp.
To my suprise, I noticed ithat adjusting the eyepiece 'focus' on the grain focuser did not seem to affect the sharpness of the pre-focused image when viewed through the focuser's eyepiece.
Is this correct?
Is the adjustable eyepiece on the grain focuser, therefore, more like a diopter correction rather than a true focus calibrator?
Thanks in advance for any input.
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