Canon EOS-1 VI. EQUIPMENT CALIBRATION ISSUES

VI. EQUIPMENT CALIBRATION ISSUES 33
AFSystem Calibration
LensCalibration
Testing Your Own Cameras
& Lenses
Ifthe camera and lens are being operated correctly, but images remain consistentlyout
offocus, there is always the possibility that the camera or lens is not performing
according to factoryspecifications. EOS cameras and EF lenses are precision
instruments, and assuch they require precision adjustments to perform at peak
efficiency. Although Canon makesevery effort to calibrate the AF systems of EOS
camerasin the manufacturing process, a small percentage of cameras require
calibration adjustmentsat the Factory Service Center (FSC) after sale.
AFsystem calibration at the FSC involves a series of tests to determine the positioning
accuracyof mechanical components such as the image sensor and reflex mirror
assemblies. Once these potentialproblem issues have been eliminated, test images are
taken using a “toollens” with known performance characteristics. The testing method
enablestechnicians to ensure that the camera is performing well within tolerancesfor
AFaccuracy. Once this has been done with the tool lens, it becomes possible to check
the performance ofother lenses the customer may have.
Because each autofocuslens contains its own microcomputer and many other internal
devicessuch as focusing motors and diaphragm actuators, lenses occasionallyrequire
calibration. Ifa focusing error is detected, the circuitry of the lens itself can be adjusted
to ensure thatit is operating according to design specs. Calibrating a lens does not
compromise itsperformance with other camera bodies because the calibration
standardsfor the lens are independent from the calibration standards for the body.
Please keep in mind thatwe do not recommend sending equipment to the Factory
Service Center unlessyou are sure that the source of your image quality problemsis not
one ofthe issues we have already discussed in this document.
Although photographersin the field cannot duplicate the testing capabilities of a Canon
FactoryService Center, it is certainly possible to test camerasand lenses at home or in a
studio to checktheir performance. The following procedure may help you determine
whether your camera equipmentis in need of calibration.
1. Perform your focusing testat a reasonable light level (office lighting or brighter) to
ensure optimum results.
2. Place the camera on a sturdytripod and use a remote switch when firing the shutter.
For maximum quality, consider the use ofmirror lock. (C.Fn 12 on EOS-1 class Digital
VI. EQUIPMENT CALIBRATION
ISSUES