Focus with Shutter or * [AF ON] button? -READ ME-

grinchy wrote in post #4254126
how many people are using this with their 40D?

and how do you know if its like the old 4-1 or 4-3?

On 40D, C.Fn IV 1-2 is equivalent with C.Fn 4-3 on xxxD cameras.
AF-ON button will lock focus, exposure will be metered and locked for every shutter actuation.
Half pressed shutter button will do nothing.

C.Fn. IV 1-3 will acts the same as C.Fn 4-1.
AF-ON button will lock focus, exposure will be locked with half pressed shutter button.

C.Fn VI 2-1 will switch the use of AF-ON and * button.
If enabled, * button lock AF, AF-ON button locks AE, exposure.

I don’t know how many 40D users go with C.Fn IV, I know that I do..

Hermeto wrote in post #4254436
On 40D, C.Fn IV 1-2 is equivalent with C.Fn 4-3 on xxxD cameras.
AF-ON button will lock focus, exposure will be metered and locked for every shutter actuation.

If it works the same as any other Eos (except the 10D), AE will be locked while depressing the * button when using Evaluative metering / one shot AF...

Is this still the case on a 40D / 1d3?

IMHO it's a bug Canon left in on purpose.

René Damkot wrote in post #4254789
If it works the same as any other Eos (except the 10D), AE will be locked while depressing the * button when using Evaluative metering / one shot AF...

Is this still the case on a 40D / 1d3?

IMHO it's a bug Canon left in on purpose.

Yes, you are right for 40D part at least, I don’t know about 1D3.
Even with C.Fn IV 1-2, AE will be locked with * button in Evaluative.

What I don’t know is what does camera meters off when there is no focus lock in Evaluative.
Metering is linked to the active focusing point alright, but what happens when there is NO active focusing point and you try to lock AE?

After reading this thread, I decided to give this a shot - been running the following on my 40D:

C.Fn IV-1 Shutter button/AF-ON button
3: AE lock/Metering + AF+start
(Manual: Convenient when you want to focus and meter at different parts of the picture. Press the <AF-ON> button to meter and autofocus, and press the shutter button halfway to attain AE lock.)

AND (because I have the BG-E2N grip, which does NOT have an AF-ON button)

C.Fn IV-2 AF-ON/AE lock button switch
1: Enable
(Manual: The functions of the <AF-ON> and <*/zoom-out> buttons will be switched with each other's function)

I've found that I can still focus fairly quickly, but AI Servo mode is sometimes slow to kick in... I have it set to AI Focus.

Hermeto wrote in post #4254853
What I don’t know is what does camera meters off when there is no focus lock in Evaluative.
Metering is linked to the active focusing point alright, but what happens when there is NO active focusing point and you try to lock AE?

If you manually chose an AF point, metering is weighted around that AFAIK. EVen if you don't keep the * pressed.
If you use AAFPS, or set the lens to MF, metering is weighted around the center AF point.

At least on my 1D2...

I switched to the * for focus less than a week ago and I am a firm believer now after shooting about 300 shots that way.

My only question is with burst shooting and one-shot AF. If I keep the * button pressed while I hold down the shutter for a burst sequence will it refocus for every successive shot? Should I switch to AI servo in that case?

In one shot AF is locked after it's achieved.
Use Ai servo (and keep pressing *) if you want to track your subject.

one of the things we lost with these CF4 settings on the 30D was FEL. Now that the 40D has an extra button (AF-ON), can you get FEL back and still have the other advantages?

door wrote in post #4262919
one of the things we lost with these CF4 settings on the 30D was FEL. Now that the 40D has an extra button (AF-ON), can you get FEL back and still have the other advantages?

Yes.
Regardless of C.Fn IV 2 setting AE lock and FE lock are preserved.

Well, just finished wading through this thread. Set my 1D to CFn4-1. Liking it alot. Not sure I'll do so with the other bodies, but if it gets inbedded, I will. Fun to see something like this hang around for three years? as a thread and still be timely.

Thanks!

Stew

René Damkot wrote in post #4256936
If you manually chose an AF point, metering is weighted around that AFAIK. EVen if you don't keep the * pressed.
If you use AAFPS, or set the lens to MF, metering is weighted around the center AF point.

At least on my 1D2...

Great, thanks!
I’ll try to check how it works on 40D..

squiress wrote in post #4263529
Well, just finished wading through this thread. Set my 1D to CFn4-1. Liking it alot. Not sure I'll do so with the other bodies, but if it gets inbedded, I will. Fun to see something like this hang around for three years? as a thread and still be timely.

Thanks!

Stew

Good call, now with a 1D in hand is the perfect time to force yourself to get used to this, as you get used to the new controls on a new camera, it just becomes part of the "upgrade"

ScottE wrote in post #2368086
Exactly. That is why I will not buy any Tamron or Tokina lenses. I will only buy Canon USM and Sigma HSM lenses that have full time manual override. If you manually focus lenses that do not have full time manual override you risk damaging the AF motor or its gearing. I demonstrated that with my Sigma 105 macro lens. (I needed a macro lens and bought the Sigma before Canon released the USM version of their 100 mm macro. I would get the Canon now.)

The distinction between CF 4-1 and 4-3 is important. With 4-1 you can point the camera at a subject you want in sharp focus, point it again at a neutral toned subject and press the shutter half way to take an exposure reading and finally recompose and press the shutter all the way to take the shot. This is useful for bright landscapes where you want to focus at a specific point and take your exposure reading from something other than the bright sky or snow.

With CF 4-3 you can keep the * button depressed and subject as it moves through areas of sunlight and shade and the exposure reading will be taken when you press the shutter to take the shot. This is useful where you are shooting in the woods where the subject is moving through areas of bright and shade such as wildlife, mountain bike racing or cross country ski racing.

Ok....a dumb question ...
If you fire off a "burst" of shots of the moving object. And you just "hold" that button down with CF4-3 set....does the camera's brain interpret that action as just you "fast" clicking that shutter button up/down so that exposure is read each time the shutter fires? And thus the moving object going in/out of light/dark areas is accounted for automagically???

-rang

rang wrote in post #4266678
Ok....a dumb question ...
If you fire off a "burst" of shots of the moving object. And you just "hold" that button down with CF4-3 set....does the camera's brain interpret that action as just you "fast" clicking that shutter button up/down so that exposure is read each time the shutter fires? And thus the moving object going in/out of light/dark areas is accounted for automagically???

-rang

Yes, with C.Fn. 4-3 that’s exactly what it does!
With C.Fn 4-1 however, exposure is locked the first time you press the shutter button half way and stays the same until you completely release it.

I prefer the default setting for C.Fn. 4 when shooting action. I do motorsports so I always shoot outside in predictable light.The camera continuously focuses while you are holding the shutter button when you are in AI Servo.

The camera sets exposure at full press of the shutter button and then locks again prior to each shutter actuation when in Continuous drive mode. When in M mode, the exposure doesn't matter anyway.

Adding another button doesn't buy me anything that I can think of.