Problem with AF confirm chip adapters on analog EOS cameras

[stan_1]

I have now several lens adapters from various lenses to the Canon EF mount with autofocus confirmed chips and I noticed that it is difficult to find an adapter where the chip works with analog EOS cameras. Most of the times the camera does show the chip parameters correctly and the focus confirm works. However when you press the shutter button you get an error. So I imagine some specifications might have changed since the same adapters sometimes work fine on digital cameras like on an EOS R with an EF-to-R adapter. Is there may be some simple trick with respect to the pins or something similar that can make these adapters work also on the analog EOS cameras.