Showing results for 
Show  only  | Search instead for 
Did you mean: 

100-400 mk1 - focusing


I have recently purchased a  7d mk2, the problem I am having when using the 100-400 mk1 is that Iam finding it difficult to focus manual or auto even in perfect lighting conditions, have tried various settings..does the lens need to be calibrated, Obtained some  crystal clear shots with the aware the lens is rather slow to focus.


Any advice would be appreciated.



I used a ef 100-400mm on a 7D for years and it performed flawlessly.  It should do so on your 7D Mk II.

Do you have the diopter in the viewfinder set wrong.  Set it to 0, or netural, and try.


The ef 100-400mm is a very good lens it is not a great lens, IMHO of course.  It served me well.  You need to seperate the two, canera and lens.  Get another body and try.  Get another lens and try.  Maybe you have another lens. Does the 7D Mk II work well with it?  If it does it is probably OK.  Does the 100-400 work well on a different 7D?

EOS 1DX and 1D Mk IV and several lenses!
08/18/2023: Canon EOS R5 C training series is released.

07/31/2023: New firmware updates are available.

CR-N700 - Version 1.2.0

CR-N500 - Version 1.3.0

CR-N300 - Version 1.3.0

CR-X300 - Version 1.1.0

06/30/2023: New firmware version is available for EOS-R5 C

05/31/2023: New firmware updates are available.

EOS R6 Mark II - Version 1.1.2

EOS R6 - Version 1.8.2

EOS R7 - Version 1.3.1

05/18/2023: New firmware updates are available.

EOS Rebel T100 - Version 1.1.0

EOS Rebel T7 - Version 1.2.0

EOS 5D Mark IV - Version 1.4.0

EOS 6D Mark II - Version 1.2.0

PowerShot Elph 360HS - Version

PowerShot SX420 IS - Version

PowerShot 620 HS - Version

PowerShot SX720 HS - Version

PowerShot G1X Mark III - Version

PowerShot G7X Mark II - Version

PowerShot G9X Mark II - Version


04/20/2023: New firmware version 1.4.1 is available for EOS R3

03/30/2023: New firmware updates are available.

EOS R5 - Version 1.8.1

EOS 1DX Mark III- Version 1.7.1

Speedlite EL-1 - Version 1.0.2

03/30/2023: Product Advisory for EF50 F1.2 L USM

03/30/2023: Product Advisory for EOS R10

02/24/2023: We've updated Share Your Photos

2/07/2023: New product announcements!

EOS R8 EOS R50RF-S55-210mm F5-7.1 IS STMRF24-50mm F4.5-6.3 IS STMRF15-30mm F4.5-6.3 IS STM
01/09/2023: Help ensure your autofocus is properly aligned with a Canon Precision Alignment
01/03/2023: Welcome to CES 2023!
12/08/2022: New firmware version is available for EOS C70
12/07/2022: New firmware version 1.7.0 is available for EOS R5