GP-E1 Compass calibration errors with Superteles only

Canon GP-E1 manual suggests calibrating the compass without lens attached. I have discovered that with my 300/f2.8IS or 600 f/4 MkII attached the compass headings only show SE, S or SW headings even with the camera pointed north.

Further testing show that this error does not occur with the 70-200 MkII or any of my other lenses. The error with the Superteles occurs just by touching the camera mount and lens mount. Removing the 1Dx only an inch from the Tele and the compass heading is correct, so it's not a lens metal mass issue that is causing the problem.

Has anyone else noted this problem or not? I'm using the latest 1Dx firmware. What firmware are you using?

Blake

<embed id="application/x-exifeverywhere" type="application/x-exifeverywhere" width="0" height="0">Further testing shows the wrong compass heading only occurs on the superteles. The GPS headings are correct with all my other lenses including the 70-200 MkII.All I need to do is touch the lens mount (not contacts) and the compass headings show only southern headings even when the camera is pointed north. Remove the lens only an inch and the headings are correct, so it's not a metal mass issue.
Has anyone else noted this phenomenon. Either way, what iDx firmware are you using?




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the superteles have huge ultra-sonic servos for AF and actuators that operate the IS element, the all contain solenoids. my guess is those magnets are messing up with the compass but I may be wrong... send an email to Canon and ask.

I use my iphone for GPS BTW.

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Originally Posted by arash_hazeghi

the superteles have huge ultra-sonic servos for AF and actuators that operate the IS element, the all contain solenoids. my guess is those magnets are messing up with the compass but I may be wrong... send an email to Canon and ask.

I use my iphone for GPS BTW.

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<embed id="application/x-exifeverywhere" type="application/x-exifeverywhere" width="0" height="0">Arash,

If it were the magnets, the compass heading would still be affected when I remove the body from the lens less than an inch from the mount. Since the phenomenon occurs at the slightest touch of the mounting plates it may be related to a grounding wire within the lens that is acting as an antenna. But that does not explain why there are only Southern headings no matter which direction the camera faces or the 70-200 is not affected in the slightest.

Only Canon can help you with this problem...good luck!

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Originally Posted by arash_hazeghi

Only Canon can help you with this problem...good luck!

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True. I sent in a description of the problems to CPS Canada last night. They responded this morning and will try to duplicate the issue on their equipment.


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Canon suggested hot swapping after calibration was the issue and that turned out to be true in part. I calibrated the compass and turned the camera off before mounting it on my 300 f/2.8 IS. and turned tha camera on. The compass now read close to the correct heading and recognized northern headings. The error was about 15 degrees. Then I calibrated the compass with the 300mm lens in place and the heading was correct. So page 16 of the manual where it recommends calibrating the compass without a lens in place for safety reasons produces compass errors, at least for longer lenses.

I'm not sure I want to try compass calibration with my 600mm attached. That would look like some kind of exotic Tai Chi :)