Your compatible camera serves as a Test Body for your Lens Professional Software!

• You only need one Test Body to calibrate all your Canon lenses.
• The only requirement is that the Test Body has accurate and reliable autofocus.
• Lens adjustments made using the Test Body applies to all camera bodies.
• The software also lets you specify the autofocus (AF) system used by each lens.

Comparable Camera List

• EOS  1DX
• EOS  1DX Mark II
• EOS  5D Mark III
• EOS  6D
• EOS  6D Mark II
• EOS  7D Mark II
• EOS  70D
• EOS  77D, 9000D
• EOS  80D
• EOS  100D, Rebel SL1, Kiss X7
• EOS  200D, Rebel SL2, Kiss X9
• EOS  650D, Rebel T4i, Kiss X6i
• EOS  700D, Rebel T5i, Kiss X8i
• EOS  760D, Rebel T6s, 8000D
• EOS  800D, Rebel T7i, Kiss X9i

Frequency Counters for USM Motor Adjustment

Very Affordable Frequency Counter Solutions

To adjust the USM motor frequency in Canon lenses, you’ll need a Frequency Counter. These tools were once expensive, but are now readily available at affordable prices.

The model shown below was purchased from Component Tester on eBay for just $14.00, and similar units can be found from other online retailers.

Inspecting Focus Compensation helps Troubleshoot AF Problems

⚠️ Viewing Focus Commpensation is NOT a test of Focus Compensation accuracy!

This menu helps you check if the Focus Compensation in the lens is working properly without Disassembly. 

• Focus Compensation allows the camera to adjust focus more accurately based on the specific lens you're using.

As you slowly turn the focus and zoom rings, the display should show smooth changes in values. If the values don’t change, or if they jump suddenly, there might be a problem—like a damaged internal part (called a wiper) or a corrupted memory chip in the lens.

This tool is useful when you're having Auto Focus (AF) issues.

Problems Caused by Faulty Focus Compensation

• Front or Back Focus
• Inconsistent AF Accuracy
• Focus Shift While Zooming (Zoom Lenses)
• Erratic Autofocus Behavior
• Poor Low-Light Focus Performance
• AF Micro Adjustment Has No Effect
• Focus Errors After Main Board Replacement

Zoom Encoder problems can affect Flash, Image Stabilization and Auto Focus

This menu lets you test if the Zoom Encoder in your lens is working correctly without Disassembly. 

• Problems with the Zoom Encoder can cause issues with Flash, Image Stabilization, and Auto Focus.

It works by showing you a signal as you slowly move the zoom ring. If the display matches the lens zoom and all boxes light up smoothly, the encoder is working. If not, the encoder might be damaged—usually from bent or broken parts inside.

This signal also helps control the flash power when using ETTL flash.

Possible Problems from a Faulty Zoom Encoder Brush

• Inconsistent or incorrect ETTL flash exposure
• Poor or unreliable image stabilization (IS) performance
• Autofocus hesitation or inaccuracy, especially at longer focal lengths
• Incorrect or stuck focal length in EXIF data
• Possible lens communication errors or camera error messages
• Flickering or image shift during zoom in live view or video mode

Having an Auto Focus Problem … start by checking the Focus Encoder

This menu helps you check if the Focus Encoder in your lens is working properly, without disassembly. 

• If you're having Auto Focus problems, this is a good place to start.

It shows you a signal as you slowly turn the focus ring by hand. If the signal moves smoothly and all the boxes on the screen light up during the test, the encoder is working. If not, there may be a problem; often caused by bent or broken parts inside the lens.

Also, this same signal is important in setting the power level for ETTL flash.

⚠️  The most common cause of encoder failure is bent or broken wiper blades on the focus brush.

Troubleshoot Subassembly Errors / Reset the use Count if you replace a Subassembly

Clear the Error Codes after Repair

Newer L-Series Lenses Record: Actuation Counts and Errors

These lenses track usage and errors from key internal components:

• Diaphragm Unit
• AF (Autofocus) Unit
• IS (Image Stabilization) Unit

Error Window

• This window identifies errors in malfunctioning units, helping you pinpoint the source of the issue.
• Example:  IS Unit – Gyro Sensor: Anomalous

This data provides a clear picture of the lens’s overall condition and can help identify malfunctioning sub-assemblies.

Reset

• Use Reset to zero the actuation count after replacing a sub-assembly.

Clear

• Use Clear to erase error codes after performing repairs.

Change the Electronic Serial Number in the Lens

Lens ID Number

• This is an internal factory-assigned serial number. This normally will not match the serial number printed on the lens. There is no reason to change this number, it's used primarily for factory reference.

Lens Body Number

• This is the electronic serial number of the lens and should match the number printed on the lens body.

⚠️ Not all lenses include an electronic serial number. If your lens does not have one, the 'Lens Body Number' field will not appear in this Menu window.

Change

• Click ‘Change’ to update the electronic serial number so it matches the number printed on the lens body, if needed.

Save and Restore Lens Calibration Data

⚠️ Always Backup the Calibration Data from the Original Main Board before making any changes.

Backup … is used for replacing Main Boards or before making Adjustments.

Restore … is used when you replace a Main Board AND you were able to save the Calibration Data from the Original Main Board

Initialize …. is used when you replace a Main Board WITHOUT the original Calibration Data

If you were not able to download the Calibration Data from the original Main Board:

1. Install the new Main Board.
2. Use this software to Initialize it.
3. Then calibrate the lens using this software.

Save Yourself Trouble Later — Use the Calibration Tab in Essential First

Before doing anything else, we recommend backing up your camera’s Calibration Data using the Calibration Data Tab in Essential. It’s the simplest and most direct way to save your data—and it gives you an easy-to-access backup for the future.

While the Main Board Replacement Plugin also saves Calibration Data, it’s part of a larger, more complex process, and the camera data backup file it creates is stored in a hidden folder. That makes it harder to find or use later if you need it.

Bottom line:
Start with the Calibration Tab in Essential. It’s quicker, easier, and gives you a clean backup you can rely on if something goes wrong down the road.