problem with 600mm f4 IS 2

[Colonel4446]

Hi all,

   I am new to the forum.

   I have run into a strange problem with my 600mm mark 2. My high speed burst using 2 differant Canon 7d mk 2's has dropped in burst rate by about 50%. It is roughly now about 5 frames per second on both cameras where normal rate is 10 fps. I am a wildlife photographer and use high speed burst all the time. The only lens I have that this happens with is the 600. All the other lenses the burst rate is right up to snuff.

   I cleaned the contacts, checked all the settings on the lens and the cameras. This did not help. This problem surfaced all of a sudden. Last week everything was fine. All other functions of the lens seem to be fine. I also put my 5d3 on it and the burst mode seems ok.

   Thanks in advance everyone,

   Colonel4446 

[TCampbell]

Can you give us more info....

Are you using "One Shot" focus mode vs. "AI Servo" mode (or possibly even "AI Focus" mode)?

Are you shooting RAW or JPEG (or both)?

[kvbarkley]

Are you using a better beamer or something with a flash?

[Colonel4446]

Hi guys,

   Both 7d mk2's are set up the same. Both cameras have 20-30k photographs through them. One is used primarily with the 600 and the other with a 300 f2.8  2. However both cameras react the same when installed on the 600, slower max burst speed.

   I shoot raw, AI servo, spot metering and center point focus. I also use 1.4-3 extenders most of the time on both cameras. However with or without the extenders the max. burst speed is now reduced on the 600.

   It does not matter what  other lens I put on these cameras including the 300 they both work fine and have maximum burst speed.

   The 600 has never been dropped or abused. It gets bumped sometime out in the bush but never has been bumped hard that would have alarmed me.

   My guess would be that someting in that lens is causing an electrical resistance and reducing the burst speed. That is only a guess though.

   I do have a better beamer but it has not been used in quite awhile. I go to single shot when using the beamer.

Thanks so much for your help with this. I really appreciate it.

Colonel4446

[RobertTheFat]

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@Colonel4446 wrote:

Hi guys,

   Both 7d mk2's are set up the same. Both cameras have 20-30k photographs through them. One is used primarily with the 600 and the other with a 300 f2.8  2. However both cameras react the same when installed on the 600, slower max burst speed.

   I shoot raw, AI servo, spot metering and center point focus. I also use 1.4-3 extenders most of the time on both cameras. However with or without the extenders the max. burst speed is now reduced on the 600.

   It does not matter what  other lens I put on these cameras including the 300 they both work fine and have maximum burst speed.

   The 600 has never been dropped or abused. It gets bumped sometime out in the bush but never has been bumped hard that would have alarmed me.

   My guess would be that someting in that lens is causing an electrical resistance and reducing the burst speed. That is only a guess though.

   I do have a better beamer but it has not been used in quite awhile. I go to single shot when using the beamer.

Thanks so much for your help with this. I really appreciate it.

Colonel4446

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Autofocusing a big lens could conceivably put a big enough load on the camera's electrical system to affect the burst rate. Have you tried adding a battery grip?

[diverhank]

The only thing I can think of is that distortion correction (and others) are turned on for this lens on your two 7D Mark II.  This may slow the burst rate significantly.  It's an easy check anyhow.  Other than that, I have no clue...haven't heard of this problem before.

[jrhoffman75]

Give Canon a call at 1-800-OK-CANON. 

[TCampbell]

Just as a test... have you tried switching to manual focus to see if that impacts the burst speed?  I'm just wondering if the delay has to do with any attempts to update the focus between frames -- which can be more difficult with a long lens.

Also, please check the settings for your AI Servo 1st vs. 2nd image priority on the camera.  (I think the 7D II has this setting).  In one mode the camera will put most prioirty on focus for the 1st frame of the burst sequence but wont be as fussy about focus for each success frame in the burst series.  If in the other mode, the camera will be fussier about re-aquiring focus between each frame and this will slow your burst speed (Canon documents this in their AF guide).

[ebiggs1]

Colonel,

I am probably the only one here to use the 600mil.  I must say I have never seen this with mine.  So, I really don't have the answer. You say if you use the lens on the 5D Mk III it is OK?  Just on either or both of the 7D Mk II's?

I think I would reset the 7D Mk II's back to factory and try it.

 I would have said it was something to do with AF but you are using AI-Servo so AF should not matter.  I believe a call to Canon is in order.  But you really need to talk with a rep that has actually used the big 600mil.  Not just one that read the book on it.

[Colonel4446]

Hi again,

   Thanks again for comments. 

   Yes I have a battery grip on the camera that resides with the 600. If you install the other camera without the grip the problem is still the same. 

   Early last week at a shoot everything was OK. At the end of the week I did another shoot and the first time I used high speed burst it had changed. No camera settings or lens settings were changed from the early shoot to the one later in the week. Lighting conditions were very similar. Keep in mind I can put any other lens I have on these cameras and they work fine. Only the 600 is the problem with or without teleconverters. 

   After thinking about it more this morning I believe it could be a physical problem with the lens itself. When I go out in the bush  of South Carolina I have the 600, camera with grip, and teleconverter on a RRS tripod with gimbal mount. I sling the rig over my shoulder and with my 300 setup on a black rapid strap head out. There is a lot of walking sometimes. Although I have never even bumped it hard there is some stress on the mounts. Possible deflection over time may be the culprit. Contact problem, broken wire, etc. I am totally guessing here but now it seems like the best scenario. The other equipment is working fine.

   Since the other lens features on the 600 seem to work I will primarily use  it temporarily anyway in single shot mode. I pretty much have been doing that anyway for static bird photos and my 300 I use for birds in flight. I will test the 600 this week in the other modes to make sure that it works well.

I will call Canon this week. Colonel4446