Re: 1DX - Ai Servo Issue - Low light focus failure! UPDATE 31/07
Thank You! this is the first hint that it may be isolated!
Sh1n1ng Forc3 said:Sycotek said:Thanks to all that have attempted to re-create this:
It's a given that the unit will not focus on -2ev low light via Ai-servo, that's only where the investigation started, if anythig the servo has issues around 1ev.
The real issue initial target lock (first frame) failing under low light - low light as in a normal light in a normal room trying to lock on a face.
7D has Ai-focus which I never use - I was comparing Ai-servo against the 1dx Ai servo. With that said the 7D af points are 4 times as large so target acquisition should be faster by default in low light.
I digress: try working in a normal room with an over head light and try locking on a persons face at 3fps and at 12fps with all points on and first point priority and attempt to lock on the targets face (say 180-200mm from 2m away). Now try an notice just how much faster 3fps is in terms of the af points "dancing" on the targets face.
At 12 fps majority of the time it drives my lens and locks up - if I rack the lens to 0 and attempt to focus the lens won't even rack... At 3-10fps the lens racks (actually tries to focus and gets a lock)
Standard 60w light in a 4x4 room isn't exactly low light ESP considering my gf is white skinned with dark hair and eyes.
The 7D regardless of frame rate gives me the initial lock immediately under the same conditions.
I here what you are saying but my 1DX doesn't have problems locking on target at -1ev like yours while in Ai Servo. It only has issues at extremely low light coupled with low contrast with a static object. 12FPS works just fine for me in Ai Servo as I cannot reproduce your specific issue. This leads me to believe there is something else going on here. Perhaps a bad batch from Canon, but I cannot say. All I know is what I have posted above.
Thank You! this is the first hint that it may be isolated!
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