Originally posted by Anvh But look at the contacts that are on your lenses, my DA lenses have different contact formation some have 5 others have 6 but they are all missing the contact next to the 7th contact but thats a contact the MZ-60 has and that contact is used on A mount for the aperture.
The contact is also missing on the DFA macro which works on A mount bodies so things are very confusing.
I googled up images of the mounts for the DA18-55, DA16-15, DA35/2.4, DA55-300, DA*55/1.4, F50/1.7 and FA35/2. They all have all the contacts the MZ-60 has (are you counting from the wrong end perhaps?), and the DA*55 has one more, probably because of SDM.
Here's a thread with several such images Originally posted by Anvh Look at the MZ-60 mount and look at the contacts that are missing.
It are the two M contacts that are use to indicate the minimum aperture, most likely it doesn't use them since it's crippled.
Beside that you run in the problem if what you say is true, that those 4 contacts are needed for digital information, since 3 of these contacts are certainly used to indicate the maximum aperture on older bodies it means you cant use F, FA, FAJ and DFA lenses on bodies with A mount and we know that isnt true.
So what do you think is the work around for that?
I already explained this, when unpowered the lens leaves them floating or grounded as appropriate. But I'll explain it again with different words, this time with concrete examples of exactly how it could work. (Note however that I'm not saying it does work exactly this way, I don't care enough to test it.)
Let's first make the numbering system clear, I've been counting counter clockwise on the camera mount, or clockwise on the lens mount. Pins 1, 2, 4, 5, 6 are used to indicate aperture range on A lenses. Pin 3 is used to indicate A mode. Pin 7 is only present on AF lenses. Pins 2 and 4 are missing on the MZ-60.
Now how A lenses work. The camera uses the mount as ground, and has pull-ups on all the pins. The pins that have insulators on the lens get pulled up, the others are pulled down (grounded). All these go to some circuitry that calculates the aperture range.
And now AF lenses. The camera applies a pull-up to pin 7. If this gets pulled down, the lens is an A lens, and the old system is used. If it doesn't get pulled down, the new system is used. I'll assume pin 7 is power, and the camera now feeds power to it. Pins 1, 5 and 6 can be used for serial data.
And finally, the actual question, how an AF lens can still work with the old A system. Well, there's no power to pin 7 (since there is no pin 7 on the A cameras). If pin n was supposed to be insulated, the unpowered circuit must have high impedance on this input. If it was supposed to be grounded, it must sink current through it. You might want to google "tri-state logic".