Using A7RV with Techart adapter. I noticed that the metering with manual-focus lenses(Leica M) on Sony cameras is based on the apertures set on the camera, not on the actual aperture opening on the lens.
Is this normal behavior on the camera?
I also notice the aperture only opens up to F2 when the manual lens is mounted. Is this a limitation of the camera?
There is no such thing as "aperture set on the camera" when an adapted lens is mounted. The aperture control wheel gets disabled and doesn't do anything. Maybe it's some kind of a glitch with this particular adapter? I only used the Voigtlander M-to-E adapter.
old-gregg wrote:
There is no such thing as "aperture set on the camera" when an adapted lens is mounted. The aperture control wheel gets disabled and doesn't do anything. Maybe it's some kind of a glitch with this particular adapter? I only used the Voigtlander M-to-E adapter.
I have the Techart LM-EA9 adapter, both camera and adapter’s firmware is up to date. I don’t think it’s a glitch. I’ve changed lenses, took the battery out trying to “reset” it. I asked the mighty ChatGPT, here’s what I got:
You're noticing that changing the aperture value on the camera body (even though the lens aperture is manually fixed) affects metering.
This happens because:
The Sony camera is "spoofed" into thinking it’s using a native electronic lens due to the adapter.
When you change the aperture setting on the camera body, it digitally adjusts exposure metering based on that value, even though the physical aperture hasn’t changed.
This is a metadata-only setting—the lens isn’t stopping down, but the camera is falsely adjusting metering as if it were.
I guess the issue is specifically to the Techart LM-EA9 adapter. I’ll get another adapter to try.
hasenbein wrote:
Isn't the metering simply dependent on the light falling onto the sensor? So that it's totally irrelevant which kind of lens is mounted??
