2 x 5D III with same lens and FW: AFMicroAdj stored only in one *weird*

[niels123]

I was manually tuning a Tamron 85 SP f/1.8 because I got a really weird curve from FoCal and wasn't trusting it. So I was taking pictures of the Spyder LensCal at different MicroAdjustmentValues and than later, on my PC checking the values with ExifToolGUI.

To my big surprise: the body where the camera serialnumber starts with 18 stores these values perfectly fine. it has firmware 1.2.3. The other body (serial starts with 05) had firmware 1.3.3 and stored only 0 in this field, no matter what I entered. Obviously with the exact same lens. I then downgraded back to 1.2.3 and tried again, but without sucess.

Same body, same lens, same firmware, yet only one stores its MicroAdjustmentValues in the raw file :-X

Any comments?

 

[neuroanatomist]

Not sure if this applies here, but the AFMA value is not written to the EXIF if the camera isn't 'actively' focusing – if you're using back button AF and not holding down AF-ON when you press the shutter, for example. The adjustment was applied when focusing, but it's not recorded.

 

[niels123]

Not sure if this applies here, but the AFMA value is not written to the EXIF if the camera isn't 'actively' focusing – if you're using back button AF and not holding down AF-ON when you press the shutter, for example. The adjustment was applied when focusing, but it's not recorded.

Canon, why?

I checked, and indeed it is the case. I sold a lens (24-105L I) yesterday and the buyer wanted to play a bit with it before puchasing. He didn't had a body with him, so I took one of my 5D's and for sake of simplicity I temporarily changed shutter button function back to AF. I hadn't switched it off yet and was uterly comfused with the difference in AFMA values between the two 5D's.

Canon, you made me flabbergasted about some weird behaviour only to be discovered in a camera that I have owned for four years ;D

 

[kaihp]

Not sure if this applies here, but the AFMA value is not written to the EXIF if the camera isn't 'actively' focusing – if you're using back button AF and not holding down AF-ON when you press the shutter, for example. The adjustment was applied when focusing, but it's not recorded.

Canon, why?

I checked, and indeed it is the case.

Niels, you're definitely not alone in hitting this one. Good news: once I realized this, I always make sure to hold the BBF to record the AMFA value. Would have been nice if Canon had a way to mark 'not recorded' in the EXIF instead of the misleading zero.

 

[neuroanatomist]

Why? I suppose because you're not actually focusing when the image is captured. Similarly, the selected AF point isn't recorded in EXIF if AF isn't active at the shutter press.

Of course, the only time you need the AFMA recorded is if you're actually determining the adjustment value manually.