50X objective, part # OKHSL50: The 0.7X zoom setting with 511X magniification offered a way to compare zoom and compound versions since both share the same focus block and can be used with the same viewing head. Objective used: M Plan APO 50x NA=0.42 WD=20.5 mm Metallurgical objective.
Field of view through eyepieces versus actual size of acquired camera image:
We used 10X eyepieces (FN 20) and eyepiece micrometer (5 mm in 100 units, 0.05 mm per unit) plus reflective stage micrometer (1mm divided in 100 parts, 0.01 mm between line centers) to determine magnification.
Field of view through eyepieces versus actual size of acquired camera image:
By comparing feature size seen through the eyepieces with the captured image we did estimate the image size to be approximately 7.4 mm wide by 5 mm high.That is significantly smaller than the 20 mm dia view through the eyepieces. | 
