Focus hunting – on Canon 17-55 F2,8 IS


On this lens I have never seen this before – but the symptom was absolutely the same like on the 17-85 lenses, so I decided to “refurbish” the USM motor.

At first, You have to take it out from the lens, and to disassemble from it the lower part, which covers the optical encoder.


After this I always make some signs on one end, to know on which position to mount it back. After taking it out from the holder, You can see that the transparent acrylic glass or polycarbonate is full of oil – which make o optical short circuit in the encoder. I usually wash it out with a kind of white spirit (or brake-cleaner from the car-industry), after which the encoder goes back to it’s place.

DPP_0003 DPP_0005

Here You can see the oil.

After assembling the focus worked perfect!


About canonrepair

Ruzsa János. Amatőr fotós, Canon DSLR váz. Amateur photographer. Canon DSLR user.
This entry was posted in 17-55 F2.8 IS, Canon lens, USM. Bookmark the permalink.

2 Responses to Focus hunting – on Canon 17-55 F2,8 IS

  1. Thien says:

    I had problem like this a lot on Canon 17-85mm!

Opinion, question?

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s