How to adjust AF on Canon 5D?

[nathan appel]

Hi, I will be converting my 5D to infrared, and I would like to know how to adjust the AF for infrared use.  I have not found any information online.  Thanks,
Nathan

[Jonathan Wienke]

You can't. The focus offset between visible light and infrared will vary from lens to lens anyway. What you'll need to do is some experimentation to figure out how much the lens needs to be adjusted from visible light focus to IR focus, and then make a mark to the side of the visible light focus indicator on the lens' focus distance scale.

[nathan appel]

You can't. The focus offset between visible light and infrared will vary from lens to lens anyway. What you'll need to do is some experimentation to figure out how much the lens needs to be adjusted from visible light focus to IR focus, and then make a mark to the side of the visible light focus indicator on the lens' focus distance scale.
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Thanks, I was under the impression that the bodies themselves can be calibrated for AF, as well as the lenses.  The major IR conversion companies (HuTech, Lifepixel, MaxMax) state that they calibrate the bodies to adjust for the IR conversion.  For the style of shooting that I will be doing, I will rely heavily on AF, so manual focus adjustments aren't an option for me.

[Jonathan Wienke]

The major IR conversion companies (HuTech, Lifepixel, MaxMax) state that they calibrate the bodies to adjust for the IR conversion.

Then they have access to the technical data for adjusting the body's focus calibration. That requires special tools to adjust the AF circuitry, and isn't something you can do at home.

[nathan appel]

Then they have access to the technical data for adjusting the body's focus calibration. That requires special tools to adjust the AF circuitry, and isn't something you can do at home.
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Never say never

[Jonathan Wienke]

It's not a screwdriver adjustment, it involves updating calibration values in a flash memory chip in the camera. Do you have the tech data describing how to disassemble the camera properly, talk to the AF circuitry, and the connectors needed?

[fnagy]

Never say never
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This really dates me, but only a while back (not too many moons ago) you could tune up your car with some basic equipment and the brains to do it right. I would not even attempt to change the plugs on my car of today which functions a hell of a lot better and more reliably.  You need the right tools( techie stuff) and be a trained techie to work on them.

Yes, you could probably hack into the architecture, I have seen people do it with cameras and other gear, it works OK most times, but not OK sometimes.  I do not want anything to go south on me in the middle of a shoot, whether I am shooting for coin or personal work.  That's why I let only well trained (I hope) people to adjust or service them to keep my gear working.

Have fun with it if you can afford it because chances are good that your 5D will become a decorative  ornament.

[kaelaria]

JW is right it's done via software, that is not publicaly available.

I did it myself too, and I found it to be a non issue unless the subject is very close or my apertures very large, which is not at all what I made an IR camera for in the first place.  At F5.6+ just point and shoot.