What's the best initial AF mode?

[ajmcdo]

I've been using my 10D for a month now and I love it. My only lens at this stage is the 28-135 IS/USM. My question for the more advanced forum members relates to the "resident" AF mode.

At the moment when I shoot I usually use Program AE or Av depending on the situation and RAW files. I've used Photoshop for years and this produces outstanding shots. I have my 10D set to C.Fn-07=0 to give a center AF point but also set the manual AF point selection to "automatic selection". Have I shot myself in the foot by doing this? Further, what is the best AF setting for general functionality? Should I start with Automatic Selection or with Center Selection? Does a manual selection to say "Automatic Selection" cancel the C.Fn-07 setting?

I look forward with great interest to your opinions and I must say that this is without a doubt one of the best forums on the web.

Thanks,

Tony McDonogh

[CyberDyneSystems]

I can't tell you what's best,. but i can tell you what I do.

I "registered" the auto slection of all 7 AF points so that in an emergency I can hit one button with my thumb and go back to all seven AF points.

I do this because I shoot birds,. and I shoot 98% of my shots with the center point only.

"Then why not set the center point as the registered point?" you ask...

Because I never need to get to the center AF point in a hurry,.. I can do it plenty fast enough "the normal way"

I use the AI focus setting (sigle shot initially then it will swithch to AI servo if needed) and as I say shoot with the center focus point most of the time.

But If a bird decides to launch into flight where I will have trouble keeping the center AF ppoint alone on the bird,. I can mash my thumb into the "hot button" and instantly have full 7 point autofocus and use the camras ability to track a moving subject acrosss AF points.

As far as exposure mode,. I tend to leave the camera in Program AE most of the time,. as I can allways roll the dial to shift apertute and shutter speed,. and then if and when a specific need arises,.. then I will switch to Aperture or Shutter priority,. or even more likely go full manual.

[slejhamer]

Tony,

When you set the AF to "automatic" (all 7 AF points) it does indeed override your registered selection (center point) until you switch to that point. I set C.Fn.13 to 1, in which case I simply hit the assist button and it takes me to my registered point. (I also have mine set to center.)

As CDS points out, the best settings for general use depend on you and your subjects. I start with the center point but will switch around frequently. If you regularly shoot moving subjects like CDS, then registering all 7 points makes sense. If you frequently shoot portraits holding the camera vertically and want to quickly focus on someone's eyes 1/3 into the frame, you may want to register an AF point that is off-center. Play around with it and see what works best for you.

Enjoy,

[perfectpixel]

If you frequently shoot portraits holding the camera vertically and want to quickly focus on someone's eyes 1/3 into the frame, you may want to register an AF point that is off-center.




I'm a little confused here. Do you mean you can register the AF point to be "some where in between the normal focus point square boxes seen in the view finder?

[slejhamer]

unstuck wrote:
Do you mean you can register the AF point to be "some where in between the normal focus point square boxes seen in the view finder?


No, sorry Unstuck, I should have said "not the center point" rather than "off center." So, for example, if you regularly hold the camera vertically and want to focus on someone's eyes at roughly 1/3 of the way from the top, you might register the AF point that is above the center point. Hope that clears up the confusion. :)

[WSpruance]

Maybe I have it wrong? I thought in servo mode - only the center circle in the viewfinder would track the bird and estimate its focal point at shutter release? Any answers will be helpful.

[slejhamer]

WSpruance wrote:
Maybe I have it wrong? I thought in servo mode - only the center circle in the viewfinder would track the bird and estimate its focal point at shutter release? Any answers will be helpful.


If AF is set to automatic (all seven points active) and you use AI servo, the camera uses the center point to set the initial focus but will track the subject if it moves to another AF point. See p. 66 of the manual, the section called "predictive AF" for more info.

Cheers,

[perfectpixel]

slejhamer wrote:
unstuck wrote:
Do you mean you can register the AF point to be "some where in between the normal focus point square boxes seen in the view finder?


No, sorry Unstuck, I should have said "not the center point" rather than "off center."

yep that's what I thought you meant.
I've heard the center AF point does a "better job" of focussing than the other peripheral ones.
I'm doing some soccer shots and was told to keep it on the center AF and set to "one shot" mode.
comments?

[CyberDyneSystems]

slejhamer wrote:
WSpruance wrote:
Maybe I have it wrong? I thought in servo mode - only the center circle in the viewfinder would track the bird and estimate its focal point at shutter release? Any answers will be helpful.


If AF is set to automatic (all seven points active) and you use AI servo, the camera uses the center point to set the initial focus but will track the subject if it moves to another AF point. See p. 66 of the manual, the section called "predictive AF" for more info.

Cheers,


Indeed! This is precisely why I have set the full auto/all seven focus points as my "preset" so I can get to this set up as quickly as possible. The full auto predictive autofocus does not allways work (particualarly of you are tracking a moving subject against a busy background,. BUT it DOES WORK. Sometimes it is quite remarkable. It seems to work better with particular lenses too.

[slejhamer]

unstuck wrote:
I'm doing some soccer shots and was told to keep it on the center AF and set to "one shot" mode.
comments?


You'll have to experiment and see what works best for you, but if I were shooting a soccer player in action I would probably set my camera up the way CDS does, using servo mode to track the subject. You might have good luck just snapping quickly in one-shot mode though.

[WSpruance]

CyberDyneSystems wrote:
slejhamer wrote:
WSpruance wrote:
Maybe I have it wrong? I thought in servo mode - only the center circle in the viewfinder would track the bird and estimate its focal point at shutter release? Any answers will be helpful.


If AF is set to automatic (all seven points active) and you use AI servo, the camera uses the center point to set the initial focus but will track the subject if it moves to another AF point. See p. 66 of the manual, the section called "predictive AF" for more info.

Cheers,


Indeed! This is precisely why I have set the full auto/all seven focus points as my "preset" so I can get to this set up as quickly as possible. The full auto predictive autofocus does not allways work (particualarly of you are tracking a moving subject against a busy background,. BUT it DOES WORK. Sometimes it is quite remarkable. It seems to work better with particular lenses too.


Thanks for the answer. Which of my lenses below would you say works best for the moving (action) shots?

[mjordan]

I've not had much luck with AI mode taking pictures of fast moving dogs (coming at me, going away and going across) nor with wind surfers and other fast moving subjects. It gets close but it seems too many of them are just a bit out of focus when I blow the images up to 8x10 or bigger.

When I was doing my testing I was mostly using a 70-200 4.0L lens. I now have a 24-70 2.8L and should get tomorrow a 70-200 2.8L IS lens. Would these work better with AI than the 4.0 lens?

I would love for it to work better because I do a lot of dog agility and herding (getting ready to go to a week long dog show in less than a week) as well as when I do the boat races, wind surfers and other things like this. Right now I use one shot and try to remember to release the shutter as much as possible during a sequence of shots so it will re-aquire focus as the subject moves.

Out of curiosity, does the EOS 3 work better than the 10D in AI mode? I have an EOS 3 but only had it about a month when I got a D30 and haven't used it much since then or now that I have the 10D. But I plan to test it a bit at the upcoming dog show... if I can get myself to put down the 10D.

Mike

[PPi-]

Mike, please drop us a line when you know if you will notice any difference. I'm being curious as I will be photographing lots of sled dogs during the winter again. Of course you people out there can point good advices for such photographing if you have some (least you have more experience than me).

[mjordan]

I'll be glad to post my experiences. I also am looking forward to cooler weather as we cart and mush our dogs as well. We don't do sleds but have a 4 wheel sleddog training cart. It looks like a wide go-cart without the engine. We've been 2 wheel carting for years and I decided to get into t he 4 wheel carts last Feb. Although our dogs are not sled dogs (Bouvier des Flandres) they were bred to pull as well as herd, so they have done real well with the four wheel but didn't do so well with the large scooter we got. I'm probably going to replace the 4 wheel cart with a 3 wheeled one so it's a little lighter (for me not the dogs) when we haul it out to run.

I hope to get a bunch more pictures this fall when it's cool enough to get back out.

Mike