Most of benefits to separating the AF and Shutter function have been discussed. This makes shooting sports or BIF so much easier. I use it for everything. If it sounds like I am proselytizing for this method I am. Once you get the hang of this you will not go back.
What this allows is the ability to bump AF or re-engage AF without dealing with the half depress. It becomes a lot more dynamic. It is either on or off. If you are tracking fast moving action you are constantly keeping the rear AF button depressed. When AF is lost it is a lot easier to bump the rear button again to obtain AF lock again. The reason you do not want the AF button in the rear and Shutter button AF at the same time is it creates conflicts and is too complex. This allows you to separate the AF function from the composition decision with the shutter release. Meaning you try to keep AF lock with your thumb and when you see the shot you want release with the shutter. If this sounds complex it is not. As mentioned above after shooting a few games you get the hang of it.
You also have the benefit of separating the AF function from exposure with the shutter button.
Where to aim the center AF point was mentioned. I keep the center point on the upper chest. The face is too small a target, at least for me. The BIF guys could probably hold focus on the eye. Just kidding.
I usually set up my cameras with three custom function groups.
1) Separate rear AF and Shutter and all applicable action photo settings.
2) Same as above with mirror lock up. For tripod use.
3) Civilian mode with normal AF and shutter function in case I have to hand the camera to a civilian.
All of this type of shooting is a lot easier if you have a lot of light. Practice with outdoor day games. Indoor can be done. You run into ISO 3200 and still using shutter speeds below 1000. Even 400-500. You can still get some good shots with good technique, timing and good support "monopod". A 2.8 or faster lens is a real help for indoor too. Almost a neccessity.
Mike Tuomey has it. That is exactly it. I also mostly leave point expansion off too. Once you have the rythym you will be suprised how many usable photos you will get.
Great info here. Untill now I have never understood the benefits of the MKII rear focus * and my low keeper rate proves it. I have went through most of the precanned recommended lists of the OP. I understand the rhythm thing but have tapped or bumped the rear focus * button when I knew I lost tracking. Should I keep the rear focus * button depressed even while physically realigning the tracking or does a bump reininitialize AF till I either loose focus or take the shot? The real question to me is how do you know where you have acquired focus or if you even have?
Are there settings I can confirm to insure I do not have rear button * AF and shutter button AF happening at the same time?
UgashikBob wrote:
Should I keep the rear focus * button depressed even while physically realigning the tracking or does a bump reininitialize AF till I either loose focus or take the shot?
I've never used a MK II and this answer is probably photographer-specific, but I tend to work the * button depending on the nature of the action.
If I'm trying to track a small object and busy background (think bird flying past brush), I'll tap the * only when I've aligned the focus point over the subject, hold it down to maintain tracking, and fire off a few shots.
Sometimes I'll lose the target, so I let up off the *, realign the lens and get the subject back on the point, then engage * again.
For larger objects, I'll hold * and everything tends to go rather peachy. Sure there are times when something will fool AF (nearer passing object and your AF picks it up, or a specular reflection or other source of bright light fooling the AF, etc), but most of the time I can keep * depressed and most any camera can track a large subject just fine.
If I'm sensing the camera is having trouble tracking, I'll sometimes "prime" the focus by pumping the * for a second or so at a time to get the camera and lens racking focus, then fire off the shots. "Cold fire" shots (where you just immediately press * then start taking the shots, even if the image looked in focus) usually result in poor results for me.
The real question to me is how do you know where you have acquired focus or if you even have? Magnified LCD reviewing for some cameras...I tend to just wait until I get them offloaded to my computer.
Also, look through the viewfinder You can tell, generally, when you've hit the mark or not, though since we're dealing with mirror blackouts, etc, it's impossible to know for SURE you got it at the moment of exposure.
Are there settings I can confirm to insure I do not have rear button * AF and shutter button AF happening at the same time?
That's easy - just manually defocus the lens on an easy subject and attempt to focus using only the shutter button - if the camera doesn't do anything, you're half way there Ensure * then focuses and presto.
UgashikBob wrote:
The real question to me is how do you know where you have acquired focus or if you even have?
Practically, when you're out on the field you really don't have time to think about it. The action in most sports is fast. So, your camera settings and operation must be correspondingly simple and smooth to capture the action. In the OP's situation I would:
1. Make the back button actuate AF
2. Make the shutter button actuate exposure only
3. Set exposure, iso, aperture, and WB manually
4. Use center point focus exclusively
5. Operate the camera in a defined, repeatable way
The way I do #5 is to put the focus pip on a central, contrasty point of the subject's body, allow the camera's AF a split second to lock on, keep the pip on target, keep the back button down, fire a burst, release the back button. I do my best to repeat this very rhythmic sequence several hundred times per match/game/event.
Welcome to the website for the photography department of Sports Illustrated Magazine
For some reason the site never updated to 1DMKIII or MKIV. The settings for the MKIII were significantly different from setting up a MKII. When the focus problems came up with the MKIII Canon claimed we just did not understand the new settings.
When I first started using the 1DMKIII the settings were different enough from the MKII that I purchased the Arthur Morris Guide. The BIF guys really wring all they can from an AF system.
1D MARK III USER’S GUIDE
I just purchased this MARK III USER’S GUIDE from Arthur Morris.
It costs $20 dollars but if you plan on shooting BIF, probably no better source. http://www.birdsasart.com/MARK%20III%20USER%20GUIDE.htm
Also, do a search on YouTube “1D III settings”.
There are a couple of GREAT videos on there where they walk you through each and every custom setting, and tell you why they did it.
JGRJR wrote:
Mike Tuomey has it. That is exactly it. I also mostly leave point expansion off too. Once you have the rythym you will be suprised how many usable photos you will get.
+1
Also take note of cputeq's comments on maintaining focus. It definitely requires some practice.
To me it looks like the only way to seperate AF from the front focus button is by using Fn!V 1-2 which has metering only on the front button and meter +AF or the rear button AF/*. If this means only the * button will initiate and hold AF it will require some discipline to remember no * button no AF.
Mikes 5 point plan looks like the way to go for me.
UgashikBob wrote:
To me it looks like the only way to seperate AF from the front focus button is by using Fn!V 1-2 which has metering only on the front button and meter +AF or the rear button AF/*. If this means only the * button will initiate and hold AF it will require some discipline to remember no * button no AF.
Mikes 5 point plan looks like the way to go for me.
After a short time the vast majority of users prefer back button focus. Try it for a week...
UgashikBob wrote:
To me it looks like the only way to seperate AF from the front focus button is by using Fn!V 1-2 which has metering only on the front button and meter +AF or the rear button AF/*. If this means only the * button will initiate and hold AF it will require some discipline to remember no * button no AF.
Mikes 5 point plan looks like the way to go for me.
To use the * back button:
Fn IV 1 - Selection 2 (Metering start/Meter + AF Start)
Fn IV 2 - Selection 1 (Enable)
C.Fn IV-1 (option 2 or 3)
2 changes exposure with every click while holding back button down, 3 keeps exposure on first click for all subsequent clicks while holding back button down.
I had focus problems like this too and I discovered the culprit was having the expanded focus points turned on. Also check you focus tracking settings and see how you've got those set.
In AI Servo be sure to aim the chosen AF sensor at the right target *before* activating the AF or else the camera will try to track the wrong thing, whether that be the wrong subject or the wrong part of the right subject.
Once it has achieved focus give it a little time tracking the moving subject before you begin shooting - this allows the camera to gather more info for the predictive AF feature to work with.
Know that the AF sensors are really thin crosses (or lines) that extend beyond the red box shown in the viewfinder. It does not cover everything within the box and can latch onto something outside it - especially if that something offers a higher contrast edge than the intended subject.
If you suspect that the camera has missed the intended subject or is not tracking correctly then release the AF for a moment, re-aim and start the AF again. Even the briefest moment is enough to trash the old predictive AF data and target info. Time will be needed again to gather new data about the subject motion.
Jon_Doh wrote:
I had focus problems like this too and I discovered the culprit was having the expanded focus points turned on. Also check you focus tracking settings and see how you've got those set.
AF expansion should not be a problem unless you did not have the chosen AF sensor on target when you started the AF or else the target was not clear enough for the camera to see it and so it chose another instead. If it couldn't see it then using a single AF sensor would not help.
The chosen AF sensor is the one you picked or, if you have full 45-point AF, the centre AF sensor.
It is neither uncommon nor unnatural when using AF expansion for us to point the camera at a subject, see that any one of the AF sensors is on target and then begin shooting, but the AF always starts with the chosen AF sensor and so we must pay attention to what that particular AF sensor is aimed at when we begin the AF. This is something we have to do when we are using only one sensor but it takes a little more discipline when using more than one.
Off the top of my head i would suggest...you are at 200MM on a 1.3x sensor so first is
1 - Shutter Speed and IS
Turn off IS and make sure shutter speed is around (200 x 1.3 x 2) = around 1/520 sec
lets say around 1/400 for kids. You can under expose if needed to obtain proper speed and then push
in post processing.
2 - AF Setup
since this is erratic movement the AF speed should be faster
(a fast shutter speed would also help but we took care of that in step 1)
Center point is fine, soccer is lots of side to side movement so
C.Fn III-8-1: with assist points to the left and right of the user-selected AF point
C.Fn III-3-1 — sharp focus is priority for first shot in a sequence;
full shooting speed given priority for all subsequent shots in a burst
C.Fn III-4-1 — When tracking a moving subject with more than one AF point active,
any closer objects will be initially ignored
C.Fn III-5-1 — “hunting” is restricted; if a new subject is totally out-of-focus,
the camera won’t try to search to focus on it
3 - Burst Frame rate
like 5 frames per second is fine, (slow) enough to get lots of images in focus.
4 - That focus button
Unless you are real good at back focus button don't mess with it, leave the main
shutter button function just as is.
You can tell, generally, when you've hit the mark or not, though since we're dealing with mirror blackouts, etc, it's impossible to know for SURE you got it at the moment of exposure.
Ensure * then focuses and presto.