Bokehddicted wrote:
I posted the theory below one year ago.
I am still certainly it is a Sony E-mount protocol tolerance problem:
The aperture value is not a discrete value: 1.4, 2.0, 2.8 but rather either an analog signal or digital continuous value in the spec of the protocol.
Anyone see some sense here?
I did some searching for info on the E-mount protocol. There are no analog signal lines, it is all done with serial communication with the lens. Manual chipped lenses regularly report aperture and focus position to the camera. It would appear if the camera has concluded the aperture changed it is because the lens digitally reported the aperture changed. I don't see why this would manifest on the newer cameras unless the newer cameras talk more often with the lens and it catches a change of state that would otherwise go unnoticed, but It would seem the frequency would just be less on older cameras not no problem at all.
I would think Sony could fix this by adding hysteresis to how much aperture change is required to cancel MF magnification. I would think this would be best as a configurable option as it would reduce correct functionality for well behaved lenses.
To me it makes more sense to fix this via a firmware update to the lens. The logic would be a bit tricky as the lens would need to track past aperture position and decide if a significant change actually happened to allow reporting a new value. This would essentially be asking the lens to not actually report the current measured aperture value in many cases. I don't see a big downside to an incorrect reported aperture as it is just for exif info and not used by the camera except to toggle out of MF magnification.
So assuming Zeiss or CV comes up with new firmware, how doe that get loaded into the lens? I assume there are no USB ports on these lenses. Sony can update firmware via the body, but I suspect this is not supported in these lenses. So maybe the lens needs to be disassembled to upgrade, or maybe it can be done via a dock for the lens. Anyone know about firmware upgrades for zeiss or CV?
Aug 23, 2023 at 04:13 PM
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