Posted: 9/24/2007 6:09:47 AM EDT
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Hey all, Have a couple question regarding getting the auto focus controls setup on the 40D. Neither going through the manual nor trial and error have gotten me the results I want. Here's my question: How to I set up the controls for auto focus lock? On my previous body (10D) I could use the shutter release button to focus, but then hold down the * button to lock the auto focus (such as when I'm shooting servo and need to move the auto focus point off the subject for better composition). What custom functions do I need to set on the 40D to operate in a similar fashion? And I'm going to be very disappointed if it's done through the AF On button as there's not one of those on the battery grip. Thanks. |
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Well, I can't imagine much has changed... I know the 10/20/30/5 D cameras all have the same cfunctions for this, so I have to ASSUME the 40D is the same, having never held one before. There is a cfn which lets you change how the shutter & * buttons work. You should consider changing the * button to focus, by changing one of the cfunctions (sorry, don't have my camera with me to tell you which one). I don't know why but cf13 seems to pop into my head, but I could be wrong about that. This means you use your finger to meter (half-press) and actually take the picture (full press), and then use your thumb to focus. This will let you keep your metering locked by pressing the shutter button halfway, then focus ::when you chose to:: by pressing the * button at will. So if you want to "lock" the AF, just stop pressing the * button. It actually seems backwards to what you were asking about, but it will do the same thing, and actually make other things easier, such as the ever-so-fun focus-recompose (or thuper advanced focus-meter-compose) maneuvers. I also have to assume that the 40D's grip is the same/similar to the other cameras, and that it has the * button on it. If not, YMMV. ::edit:: I just re-read your post and noticed you wanted to lock AF, not stop it from AF. If the 10D had this feature, I'd look at the cfns in your 10D and try to match them up to the 40D. I'm 99% sure our 10&20D have the same functions (except 20D added more) and assume the same is true of future models. I know the 5D and maybe the 30D added a few "invisible" af points, that only were used to pass off af to another point when shooting in AI servo mode. You can't manually select these points, but if you have ALL AF points active, there are an additional set of points inbetween the outer ring & middle point that will transition AF. So, if you're wanting to reframe, you can try to use all points AF, although I think that sucks, as it sometimes picks the wrong thing to focus on... although once you have the proper thing being tracked, it will pass off to the next AF point (even invisible ones) much more smoothly and reliably. |