StereoZOOM immersion microscope for gemmological applications

Horizontal microscope for examination of coloured gemstones in immersion liquid.

SYNTEST mit Optik ZEISS 2000, trinokular
GEMMASTER mit Optik LEICA S6E, binokular
Binocular zoom range1 0.65x - 5x 0.63x - 4.0x 0.63x - 3.0x
Trinocular zoom range1 0.65x - 5x binocular only binocular only
Eyepieces 10x / 16x / 25x 10x / 16x / 20x 10x / 16x / 20x
Total magnification1 with:      
Eyepieces 10x 6.5x - 50x 6.3x - 40x 6.3x - 30x
Eyepieces 16x 10x - 80x 10x - 64x 10x - 48x
Field with 10x eyepieces (mm)2 23mm 23mm 23mm
Field with 16x eyepieces (mm)2 24mm 25mm 25mm
Eyepiece adjustment range (mm) 55-75mm 55-75mm 55-75mm
Eyepiece diopter adjustment both only one only one
Working distance (mm) 92mm 110mm 110mm
Optionale objectives 1.6x / 2.0x 1.6x / 2.0x 1.6x / 2.0x

1 Total magnification is the product of the eyepiece and the power of the zoom objective. Example: (16x eyepiece) * (0.63x - 4.0x objective) = 10x to 64x. In gemmology the figure 10x of the total microscope magnification is used for diamond grading. Therefore most microscopes are equipped with 16x eyepieces. It's a simple intention if starting with 10x total magnification to get a higher magnification at the end of typical 64x (instead of 6.3x - 40x with 10x eyepieces).

2 The field at 10x total magnification is the diameter in mm of the microscopes picture viewed by the observer. It's a quality feature of the eyepiece and the objectives. Typical range is 20-25mm at 10x depending on the manufacturer of the optical system. Of course at 6.3x the field is much wider (63mm) than at 64x (4mm).