I has a question, am really really interested in the FL 55 1.2 adapter now, but i'm not quite clear on how the autofocus confirmation chip will work -
Basically, manual focus, when the part I want in focus gets into focus, the AF point will light up?
Or what am I missing here...
I can field that, I haven't got my FL55 or adapter yet, but i've glued one of the exact-same chips onto my Samyang 35/1.4.
Basically, the EOS AF system workd as follows:
- Light goes through the lens, hits the mirror, enters the AF-sensor in the camera.
- AF sensor can tell whether the lens is front-, back-, or in-focus.
- Camera tells lens "focus so much distance further or back"
- Lens moves its AF motor until the camera says 'stop'.
- Lens says "ok, i'm stopped"
- Then camera lights up the red box in the viewfinder to tell user that it's in focus.
Now, it's silly, in a way, how this works. If the lens doesn't say "i'm stopped", the camera won't light up the AF box (even though it's the AF-sensor in the camera that decides whether it's in focus or not). So without that AF chip in the lens, the viewfinder won't light up the AF-box, even though it knows perfectly well that it's in focus.
So the AF chip that Ed uses (and lots of others use it too), basically emulate the "OK, I'm stopped" command. Your hand turning the focus ring is the motor. It works basically the same as with a real EF-lens set to Manual Focus, hold down the shutter halfway, turn the focus ring and when it's in focus the red dot in the viewfinder lights up (keep turning and it'll go off because you're out of focus the other way).
The adapter can (and Ed will have to answer what the default is set to), work even better than an EF lens, you can set it to 'Focus Trap' mode. As in, you hold the shutter button down fully and it's won't take a picture if it's out of focus. Keep the button pressed, and either turn the focus ring, move yourself, or move the subject, and when it's in focus it'll fire a shot. I've turned off that mode on the chip on my Samyang because I didn't find it too accurate, if I was turning the focus ring fastish, by the time the camera reacted and fired the shot, the subject was OOF in the other direction.
But the best thing about the AF chip is the EXIF data, you can set the focal length and aperture, say "LensModel: 35-35mm" and "FNumber: 1.4", some programs I use like LuminanceHDR refuse to work (easily) if those two aren't set in the EXIF...