Mr Magic Carpet Ride's Blog

Digital Cinema/HD Video/Commercial Video Production

A Solution to Back-Focusing Problems With the Sony PMW-EX3 February 14, 2011

Filed under: HD Video — mrmagiccarpetride @ 12:08 am

Hello shooters!  I recently was heartbroken after reviewing footage from a recent concert I shot with my EX3 where I realized that my footage was soft when I zoomed out for wide shots.  This was particularly confusing because I was using full manual focus with no auto assist focus on and the subject was very sharp when zoomed in all the way.  I had never had a problem like this before with any camera and had never heard of back focusing.  After doing some research I found out that it is not necessary to do any updates to the firmware to resolve the problem as many forums were saying.  Steps to correct the problem are below…

1.  Set your camera to 1080i60 even if you don’t normally shoot this way, it will make the adjustments more accurate.

2.  Print out the located below “Back Focusing Chart” and resize so that it fits on an 8.5″ x 11″ piece of white paper.

3.  Tape the paper to a well lit wall as level as possible.

4.  Set up a tripod about ten feet (three meters) from the chart with the camera at the same height as the chart.

5.  Make sure your zoom is set to servo and not manual.  (Located on the bottom of the camera)  Zoom all the way into the chart so that it takes up the entire frame on the viewfinder.

6.  Set the camera to full auto focus using the focusing ring and the switch on the side of the lens.

7.  Go to the “Lens” menu in the main menu when your camera is in camera mode.

8.  Select “Auto FB Adjust” and the camera should begin automatically calibrating itself.

9.  If the test fails you might need to double check that you are shooting in a well-lit environment.

10.  Your camera’s back focusing problems are now history!

This helped me and I hope it helps you too.  You can also find several other back focusing charts by searching in Google, I just included this one here to save you folks some time.  Please feel free to comment or contact me with any questions.

Happy shooting!

Back Focus Calibration Chart

Mr. Magic Carpet Ride Productions Back Focusing Chart


20 Responses to “A Solution to Back-Focusing Problems With the Sony PMW-EX3”

  1. Frank Says:

    I am having a problem with my center focus point. When zoomed out pic is fine. Between Z14 and Z38 the subject is out of focus in middle of screen…ouside areas are focused. I have noticed this especially when Brides are coming down the isle…I am a videographer. I tried doing what you said above, but it did not resolve the issue. Any help would be appreciated.

    • Hi Frank,
      I have to say that is a new one to me. I also have had good luck on occasion with taking the lens completely off and then putting it back on. It sounds like that could be something with the way the lens is sitting on the body. If all else fails you should surely contact Sony to see what they have to say.

      Thanks for the comment. Best of luck!

  2. haridas Says:

    hi i have beckfocus problim in my camera but my opiction is closed auto fb adj …. so what can i do i have ex3 sony camera

    • Hi, thanks for your question. I’m sorry, but I’m not sure if I understand your question. Do you mean that the menu does not give you the option to perform the test?

      Let me know how I can help. Thanks.

  3. Royce Says:

    It doesn’t work. Focus is still soft.

    • Hi Royce,
      bummer. Try taking off the lens and putting it back on; sometimes it can fix the issue. Unfortunately if the back-focus adjustment doesn’t fix the issue the only option might be to call Sony. I had some pretty bad luck with mine in that it seemed to be sharp sometimes and soft at other times. The test would fix my problem but so would taking the lens on and off.

      Sorry for the troubles you’ve had. Let us know if you find a solution.

      Good luck.

  4. tom Says:

    This is not news. These instructions are in the PMW-EX3 operating instructions under “Adjusting the Lens” “Adjusting the Flange Focal Length” On page 34 of my manual. When you change lenses and switch back, this adjustment is saved in memory.

    Adjusting the Lens
    The supplied VCL-614B2X and the optional
    XS8X4AS-XB8 (see page 35) specially designed
    for the PMW-EX3 are called “exclusive lenses”
    in this manual.

    Adjusting the Flange Focal Length
    It is necessary to adjust the flange focal length
    (the distance from the lens flange to the plane of
    the image along the optical axis) if the focus does
    not match properly from telephoto to wide angle
    during zoom operations.
    Repeated adjustment is not necessary as long as
    the same lens is used.

    •If a subject of insufficient contrast is used, or if
    the camcorder or subject moves during the
    adjustment, adjustment cannot be made
    properly. Once the adjustment begins, do not
    touch the camcorder body or lens until it ends.
    • When the Shutter is in SLS mode, be sure to set
    the SLS setting to OFF before starting the
    • Be careful that no light source, such as a lamp,
    the sun, or a bright window, is in field of view
    during flange focal length adjustment.

    1 Start the camcorder in Camera mode
    by setting the power switch to
    2 Set the IRIS switch to AUTO.
    3 Place a high-contrast subject, such as a
    flange focal length adjustment chart,
    about 3 m (10 ft.) away from the
    camcorder, and light it well enough to
    provide a sufficient video output level.
    4 Set the ZOOM switch to SERVO
    (Power Zoom mode).
    5 Press the MENU button to set the
    camcorder to Menu mode, and select
    (the LENS menu) then “Auto FB
    ADJ” from the menu.
    6 Move the cursor to “Execute” then
    press the joystick or the jog dial.
    The adjustment begins.
    During adjustment
    The in-progress message is displayed.
    When the adjustment finished
    The completion message is displayed.
    If the adjustment fails
    Check the conditions of the subject and lighting
    then perform the adjustment again.

    When a lens other than the exclusive lenses is
    used, adjust the flange focal length manually.

  5. Steve Says:

    Anyone had any problems with “Pumping” video? from an EX3?… a couple of shots from my last doci. are “Pulsing/Pumping”… This has only happened, so far, on a wide shot… I have sent the camera back to Sony with a sample video of the fault, but all I got back was… “We have upgraded the software and cannot repeat the fault in house!” It happened again today! The only thing that I saw when reviewing the clip (in the viewfinder) was a “black” clip, with “Cannot Proceed” when I wanted to play it. Only after transfer and viewing I saw the pulsing effect again… Any ideas as to what it could be…
    thanks… Steve.

  6. Joshymon KM Says:

    After I adjusting AutoFB in EX-1 camera through maintenance menu, it showing :NG Time out”. anybody have solution??

  7. Anonymous Says:

    Frightfully bad article. Waiting for some interesting material.

  8. Thanks for this. Also works on the PMW-200. We were having all sorts of focussing issues. Printed off your chart, followed the instructions and now everything is much crisper.
    I know there are instructions elsewhere, but these are clear and easy to follow, and the chart is perfect. Thanks again.

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  10. Mark Hamburg Says:

    Thank you so much Mr Magic.
    That worked like a charm.
    What a relief!!!

  11. tamil Says:

    ng time out issue what can i do?

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  13. E Says:

    Any thoughts on if you need to back focus when switching btw a .75 wide angle adapter and the stock lens with the pmw-300?

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