Originally posted by stevebrot CIF only works with the center point, regardless of how you get there and AF must be enabled on the bpdy. This was a thread on this topic some time back and I confirmed with my Sigma 17-70/2.8-4 (C) at that time how it works (AF turned off at lens...AF turned on at body).
Steve
I'm aware of CIF only being utilised when the camera body is in AF mode, I just have no lens to test that has a AF/MF switch. I wondered because when I use my DFA100 and FA50 in MF mode, you can have the focus point detection anywhere you like, you're not stuck with it being centre point like I am with the A 50/1.7. This got me thinking... if I owned a AF lens therefore that had a AF/MF switch, if I then put the body in AF mode, and the lens in MF mode, would the directional pad select focus points work normally (like they can be in MF mode) and therefore I could actually also CIF from a point off centre?
But if as you say you've tested it with the Sigma 17-70 and did as I ask (AF on body, AF off on lens) and confirm that when CIF is enabled in the menu, that you are still only given a single centre point for the focus point then that answers my question.
Originally posted by stevebrot Both of those lenses are KA mount and will act the same as your A 50/1.7 and other manual focus lenses. Your D FA 100/2.8 has screw-drive AF and lacks in-body focus motor and cannot be used with CIF. Some might suggest masking the "data" contact on the mount, but turning the focus ring with the AF pawl engaged risks damage to both camera and body.
What is your use case for CIF?
Steve
Yeh i didn't want to go messing with contacts, I think (once) I managed to get CIF working on a AF lens by not turning the lens all the way around and getting that satisfying 'click', it kinda worked but exposure was way off, so yeh not fussed about that. I'm fine with not having CIF working on certain lenses and only on others. I have just simply noticed that the when using MF on the FA50 and DFA100, it's real nice to be able to have a SEL mode and single focus point off centre somewhere to help you nail that focus. I wondered if the Samyangs would give that also but I thought I would be clutching at straws.
CIF I could use for a heap of things really. Thus far my month without using AF is going rather well and I'm enjoying the process. I could see me ditching AF for all those things that stand still, where I need AF would be moving stuff, and in AF.C mode likely. CIF would possibly be the next best thing in MF world to being able to do that, it would be neat if the capture could fire from a point that wasn't just the centre however... ce la vie.