Macro zoom objective has been studied to be applied to 1/2" and 1/3" CCD, with the possibility of variable focal at continuous scale for magnification between 0.8X (= scale 1:1.25) and 4X (= 4:1), with a working distance of about 98 mm ± 4 mm.
   To enlarge the range of magnifications, four converters are available: 0.7, 0.5, 0.4 and 0.3. These converters allow to have: 0.56X ... 2.8X, 0.4X ... 2X, 0.32X ... 1.2X, 0.24X ... 1.2X.
   This lens can be mounted on a practical stand; the illumination can be of two types: ring and axial illumination with cold light, with optic fiber.
   To inspect narrow cavity, it is advisable to use axial illumination or incident light with reflecting substage mirror for the projection, parallel to the axis, of the light; this eliminate completely eventual shadows and allows a perfect inspection.

Magnification (reproduction scale) on CCD	0.8X (1:1.25)	1X (1:1)	2X (2:1)	4X (4:1)
Max. diaphragm aperture	6.6	6	5.2	6
Resolution with reference to the monitor	500 TV lines	500 TV lines	500 TV lines	500 TV lines
Resolution with reference to the subject	22 µm	17 µm	8 µm	4 µm

	Magn. 0.8X	c.v. mm	Magn. 1X	c.v. mm	Magn. 2X	c.v. mm	Magn. 4X	c.v. mm
Magnification on 14" monitor with 1/2" CCD	about 36X	8.2x6.1	about 45X	6.4x4.8	about 90X	3.2x2.4	about 180X	1.6x1.2
Magnification on 14" monitor with 1/3" CCD	about 48X	6.2x4.6	about 60X	4.8x3.6	about 120X	2.4x1.8	about 240X	1.2x0.9
Magnification on 14" monitor with 1/3" CCD but with 0.7X converter	about 34X	8x5.9	about 42X	3.3x2.5	about 84X	1.7x1.2	about 168X	0.8x0.6
Magnification on 14" monitor with 1/3" CCD but with 0.5X converter	about 24X	9.3x6.9	about 30X	2.4x1.8	about 60X	1.2x0.9	about 120X	0.6x0.4
Magnification on 14" monitor with 1/3" CCD but with 0.4X converter	about 19X	9.9x7.3	about 24X	1.9x1.4	about 48X	0.9x0.7	about 96X	0.5x0.3
Magnification on 14" monitor with 1/3" CCD but with 0.3X converter	about 14X	10.5x7.8	about 18X	1.4x1.0	about 36X	0.7x0.5	about 72X	0.3x0.27