AHHH...Custom Function 4 Hurts!

Cason

Did you hear that big boom? That was my head exploding after attempting to learn about focusing. I so want to understand Custom Function 4!!

Right now, I have my 30D Custom Function 4 at 1, and AF at AI Servo. Having my camera set this way will allow me to use the back (*) button to lock focus and shutter to lock exposure. If I want to track a dog, I can contine to hold * and press the shutter button to capture. If I want to focus on a person's eye, I can simply tap (*) to lock focus, press the shutter half way to lock exposure, recompose and shoot.

Is this method better than holding the shutter button half, recompose and shoot? I know that the angle will change and make the eye OOF if the DOF is shallow and I am close to the subject.

Did I understand CF4 @ 1 correctly?

wxwax

You can't recompose and shoot with the shutter button in AI Servo, the bugger keeps on refocusing as long as you have the shutter button depressed. That's where the * custom function comes in handy.

In any other focus mode, you can use the shutter button to recompose and shoot.

SloYerRoll

wxwax wrote:

You can't recompose and shoot with the shutter button in AI Servo, the bugger keeps on refocusing as long as you have the shutter button depressed. That's where the * custom function comes in handy.

In any other focus mode, you can use the shutter button to recompose and shoot.

Is that the same thing as AF-C on Nikons?
I'm trying to be bi-lingual as to not sound like a toolshed around Canon users.

wxwax

SloYerRoll wrote:

Is that the same thing as AF-C on Nikons?
I'm trying to be bi-lingual as to not sound like a toolshed around Canon users.

I'm afraid I don't know Nikons. Maybe Harry can answer?

Harryb

SloYerRoll wrote:

Is that the same thing as AF-C on Nikons?
I'm trying to be bi-lingual as to not sound like a toolshed around Canon users.

With Nikons you can set the back AE-L/AF-L so that it will lock focus instead of half pressing the shutter release. So you lock focus by pressing the AE-L/AF-L and then you can recompose and take the shot. It takes a bit of getting used to but it is quite effective once you get used to it.

ian408

When you use the custom function, you effectively move focus from the
shutter button to the '*' button. It can be hard to get used to but once you
do, it's pretty nice.

Cason

This is something I'm going to have to try for a couple of weeks to see if I like it.

I've read that when it comes to recomposing, those that use the * button with One Shot (CF4-1) have more keepers as opposed to using the shutter button when recomposing (CF4-0). I don't know what the difference would be. I will have to see for myself.

Avants

ian408 wrote:

When you use the custom function, you effectively move focus from the
shutter button to the '*' button. It can be hard to get used to but once you
do, it's pretty nice.

I agree. I used to go back and forth between this function as needed, but now use it full time. It took some getting used to in the beginning but glad I tried it.

Scott_Quier

I tried it once, about 5 months ago, and couldn't make my fingers/mind (if I have one) make the connection.

Then, after having issues with loosing focus during a wedding procession, I got really upset and tried it again. This time, it all seemed to gel and I've been a CF-4/1 user ever since.

I also find that my percentage of keepers has greatly improved since the transition.

LiquidAir

After shooting a series of portraits at f/2 where I had to reaquire focus for each shot, reframe and fire, I decided the the * button focus had to be better. I shifted over then and have never looked back. Now I often focus just once for a whole series of shots.

SloYerRoll

Harryb wrote:

With Nikons you can set the back AE-L/AF-L so that it will lock focus instead of half pressing the shutter release. So you lock focus by pressing the AE-L/AF-L and then you can recompose and take the shot. It takes a bit of getting used to but it is quite effective once you get used to it.

Thanks Harry,

I understand all the AE/AF functionality on the Nikon half. I haven't played w/ it enough since it seems a bit ackward though. I'm going to go out and try it again though now that I remember it's even there! Now it makes sense in Canon talk now too!

Cheers,
-Jon

rwells

I posted this info in another thread, but I'll repost here because I believe it will answer your questions.


< I'm not sure what body your shooting, but if it's a Canon 20D or 30D, you can set your C.Fn #4, to option 3. That sets the camera to use the back * button for focus, and the option 3 does not lock exposure. That's how mine is set up and works well for me. This allows for a shot like your coach, in AI Servo mode, to focus on his face, release the * button, then recompose the shot. Wallah, where you want to be in focus is, and you can still recompose the shot.

C.Fn #4 has other options that may or may not work for you. You can choose to also have, not only the focus, but also have the exposure locked when you initially hold down the * button. That sounds a little confusing even to me... So, what that mode would do is: pushing the focus button and holding it in AI Servo mode, would now allow tracking of your subject, but the exposure would have locked at what was metered at the time when you FIRST pushed the focus button. (Clear as mud?)

I don't like that. I want to be able to focus where I want, then recompose and still have the camera meter correctly for how I've recomposed the scene. Also, while tracking a subject, you DO want the camera to be actively metering the scene. (This mode would be option 3)

All the people that I know that have given the back * button a decent try, won't go back to the shutter/focus setup.

Give it a try and see if it helps you out.

Oh, also a little tip: On a 20D & 30D when in AI Servo, when you hit the focus button, the focus "square" only lights up long enough to get your initial focus, it then goes out and stays out while tracking. In darker situations, like Friday Night Football games where it's hard to see anything, I'll often focus, track some, then let off the * button and reapply focus so that "I" can see where the heck the center focus square is!!!

The 1DMK** series lights up the focus square as long as your holding the focus button down. This helps your ability to track a subject A LOT, and is something I wish Canon would incorporate in all of their cameras. >

LiquidAir

One thing I have noticed with my 5D is that evaluative metering still pays attention to the metering value at the focus point with C.Fn 4 set. You'll notice that the metering value locks in when you hit the * button. I think the theory behind evaulative metering is that it wieghts the metering value at the focus point heavily against the rest of the scene. My guess is that When you set C.Fn 4, the metering system spot meters on the focus point and weighs it with a average value when you press the shutter. When using spot, partial, or CWA the exposure value is set when you press the shutter. I always shoot in manual mode so I haven't bothered to spend much time working out the details but if you use any of the metered exposure modes this is worth looking into.

rwells

LiquidAir wrote:

One thing I have noticed with my 5D is that evaluative metering still pays attention to the metering value at the focus point with C.Fn 4 set. You'll notice that the metering value locks in when you hit the * button. I think the theory behind evaulative metering is that it wieghts the metering value at the focus point heavily against the rest of the scene. My guess is that When you set C.Fn 4, the metering system spot meters on the focus point and weighs it with a average value when you press the shutter. When using spot, partial, or CWA the exposure value is set when you press the shutter. I always shoot in manual mode so I haven't bothered to spend much time working out the details but if you use any of the metered exposure modes this is worth looking into.

The C.Fn4 does not change nor affect the metering type that you have selected, it simply (better put: CONFUSINGLY) addresses things like: using the back * button for focus, etc. --- there are options to C.Fn4 --- you can choose among them:

• Option 0: AF/AE lock --> pressing the * button locks the exposure, shutter button still used for focus
• Option 1:AE lock/AF --> pressing the * button locks the focus, but not the exposure, the exposure is locked by holding down half-way on the shutter button (strange)
• Option 2:AF/AF lock, no AE lock --> the shutter button half-down is as normal - when you hold the * button, the focus is locked, but not the exposure
• Option 3: AE/AF, no AE lock --> using the * button acquires focus but does not lock it (if you want it locked, simply let off the * button), also activates the meter (of your choice). The shutter button is only used to release the shutter.

Please keep in mind that the shooting mode (single shot - AI Servo also changes how some of the options work)

In Option 3 (that I use), in single shot mode, pressing the * button will acquire focus and exposure. In this single shot mode, it will effectively lock the focus, but not the exposure. -- In AI Servo mode, pressing the * button will acquire focus, but also maintain focus while tracking your subject. It also uses the meter (of your choice) actively changing as needed.

So, you can see that for sports in particular, Option #3 is a clear winner.

I also like Option #3 for all other shooting. It allows you to focus on a subject, let off the * button, and re-compose the shot with the meter (of your choice) actively doing its job.

Hope that helps clear things up...

KED

RTP wrote:

This is something I'm going to have to try for a couple of weeks to see if I like it.

I've read that when it comes to recomposing, those that use the * button with One Shot (CF4-1) have more keepers as opposed to using the shutter button when recomposing (CF4-0). I don't know what the difference would be. I will have to see for myself.

I was drawn to your thread for a somewhat different reason -- I have had my 1D for about four months, and shoot a lot of sports using C. Fn 4-3, which has me holding * down more or less continuously over the two hour duration of a game. It literally HURTS -- some ordinarily-unused muscle in my forearm starts to get really sore by the end!

CookieS

I have small hands, and on my 1D2N It hurts my thumb and foream also, Im never sure I completely trust the camera to KEEp focusing. but the eye hand thumb coordination seems too much for my little brain to work on, and with the weight of the 1D its painful. Now my 30D for back up i may try it again, But in the post above it says that in AI servo you can press the * button to start the tracking , so does that mean you dont have to HOLD the* button the whole time> and its still keeping the focus???

Cason

CookieS wrote:

I have small hands, and on my 1D2N It hurts my thumb and foream also, Im never sure I completely trust the camera to KEEp focusing. but the eye hand thumb coordination seems too much for my little brain to work on, and with the weight of the 1D its painful. Now my 30D for back up i may try it again, But in the post above it says that in AI servo you can press the * button to start the tracking , so does that mean you dont have to HOLD the* button the whole time> and its still keeping the focus???

When in AI servo, you still have to keep pressing the * to track.

By the way, I'm loving it so far. I have more keepers. The real test will be tomorrow night for a 3 hour event. I will see how the thumb does.

ian408

Glad to hear this is making a difference for you.

KED

CookieS wrote:

I have small hands, and on my 1D2N It hurts my thumb and foream also, Im never sure I completely trust the camera to KEEp focusing. but the eye hand thumb coordination seems too much for my little brain to work on, and with the weight of the 1D its painful. Now my 30D for back up i may try it again, But in the post above it says that in AI servo you can press the * button to start the tracking , so does that mean you dont have to HOLD the* button the whole time> and its still keeping the focus???

In AI Servo, as long as you hold * the camera will continually refocus as you track your subject. Once you let off the *, it will lock focus temporarily at the distance at which is was focused when you let off, hence RWells' references to recomposing, above.

rosselliot

I'm guessing that when using customer function 4 in mode 1, then you have the exposure on spot metering? (when only the little dot is illuminated, not the little parenthesis things around it?) I've been using this, and it works great, until I'm trying to get a shot like this, and I have to keep redoing it to get the right exposure:




this was my first time shooting in this function....so I was pretty happy with most of the results, since I didn't do much to them in lightroom/photoshop:



- Ross

LiquidAir

rosselliot wrote:

I've been using this, and it works great, until I'm trying to get a shot like this, and I have to keep redoing it to get the right exposure:

I find shots with difficult light like this to be easier with manual exposure. I'd start at ISO 200, 1/200s and f/5.6, take a shot and tweak the shutter speed to get it right.