Top quality AF accuracy tester for 35mm film cameras.  If you work on film cameras this is the tester you will use everyday.  Accurately checks focus at the film plane and you can instantly see the results on the testers monitor.  The unit features a video out so you may use a larger monitor. The 35mm CCD imager test head has somewhat of a gain adjustment by changing the shutter speed setting.  The tester unit itself has a trigger level setting which adjusts the imagers ability to capture the image at the film plane depending on the light level and shutter speed. Invaluable when checking AF compacts as there AE programmed shutters vary the aperture and shutter speed automatically. There is a A and B save setting so you can compare 2 different images as you would when you are comparing images during focus adjustments. Your intended test target image will capture the best if you can vary/control  the amount of light that illuminates it. You may email me at gray@uscamera.com if you have questions.  This tester originally cost $2500. Upgrades were available at one time so we paid an additional $1800 for upgrades which gave the unit a much easier image capture and better overall image resolution.  Operates on 110-120 VAC 60hz. Includes all cables required for use.