Improving AI-Servo accuracy for street shots?

I agree with shadowblade. It's not neurosurgery to keep an AF point on a target. If the image is OOF and the AF point is on the subject, then the lens/camera are at fault.

Never mind proper handholding technique or maybe trying to optimize in-camera settings for better results? Yeah, no. New, more expensive gear still isn't the answer; especially with no more info from the OP.

The fact that moving to auto AF point selection was chosen as a possible remedy to the problem points to probably just not being as familiar with the camera as they could be. And getting a new camera will never fix that. Asking questions, getting tips and experimenting with the current gear will go much further to the goal of higher success rates.

Your average photographer with any degree of competence will already be using an optimal shutter speed and adequate handholding technique - it's not like we're dealing with long telephotos with no IS here.

Anyway, 'proper handholding' technique does nothing for focus. If camera shake is the issue, the whole image will be motion blurred. The problem isn't that the whole image is blurry - it's that the object the AF point is aimed at isn't in sharp focus, but another part of the image is. That's an AF problem.

A lot of the time, with non-1D Canon bodies, you can be tracking the subject perfectly with a peripheral AF point, only to find that the subject remains out-of-focus, as if the AF system just can't keep up.

Shadowblade wrote in post #13995472
Can't anyone keep an AF point on target? It's not the most difficult thing in the world.............

There speaks a man that hasn't tried shooting birds in flight

Shadowblade wrote in post #13995610
Your average photographer with any degree of competence will already be using an optimal shutter speed and adequate handholding technique - it's not like we're dealing with long telephotos with no IS here.

Anyway, 'proper handholding' technique does nothing for focus. If camera shake is the issue, the whole image will be motion blurred. The problem isn't that the whole image is blurry - it's that the object the AF point is aimed at isn't in sharp focus, but another part of the image is. That's an AF problem.

A lot of the time, with non-1D Canon bodies, you can be tracking the subject perfectly with a peripheral AF point, only to find that the subject remains out-of-focus, as if the AF system just can't keep up.

As has been stated.. it's not like this is a BIF shot, hockey game, race car, etc. In those cases.. better bodies' AI Servo pay big dividends; these don't look like those type of "action" shots.

artyman wrote in post #13995679
There speaks a man that hasn't tried shooting birds in flight

Really?

ouch.

Put the AF on the back button so the shutter does only exposure metereing, there's a custom function to do that. Set the shutter release priority to Focus versus release, there's a custom function for that too. Now set the camer into AI servo mode, and track the subject with the back button AF and focus point on their face for a few second before you press the shutter to capture the image. Don't use AF point expansion for what you are doing, it will make things worse. AF point expansion works great when the background is uncluttered and a consistent tone like birds against a blue sky. But it will confuse the AF system even more in street photography. Do these things and you should easily get 90% or better in focus. It takes some practice to train the thumb if you are not used to focusing that way.

135mm F2 wasn't a upgrade to my 70-200mm F4, it is for low light purposes and I happened to be using it on the street.

Anyhow, the reason I switched to auto AF is if they move off the center point, they other points will pick it up. 60D also has no AF point expansion, I believe that is 7D only. Anyhow, thanks for the tips so far guys.

Shadowblade wrote in post #13995610
Y
Anyway, 'proper handholding' technique does nothing for focus. If camera shake is the issue, the whole image will be motion blurred. The problem isn't that the whole image is blurry - it's that the object the AF point is aimed at isn't in sharp focus, but another part of the image is. That's an AF problem.
.

I will disagree. AF consists of multiple mini-sensors, and is subject to the same issues as the main camera sensor: e.g., hands shake blur. If there is too much shaking with not enough light (necessitating relatively long exposures for the AF sensors), AF errors should increase, so one will often have wrongly focused (front or back focused) shots.

For street shots, even if just once, try using your Sigma 30mm (to extend depth of field) and set on manual. Then use zone focusing, whereby you preset the focus to say 12 feet, with DoF giving you sufficiently sharp photos between, for example, 8 feet and 16 feet, depending on f-stop, of course.

As your subject falls into the 'zone,' you can quickly put camera to eye, compose, and click, all within a second or less, while not having to worry about where the AF point falls.

Significa wrote in post #13996618
135mm F2 wasn't a upgrade to my 70-200mm F4, it is for low light purposes and I happened to be using it on the street.

Anyhow, the reason I switched to auto AF is if they move off the center point, they other points will pick it up. 60D also has no AF point expansion, I believe that is 7D only. Anyhow, thanks for the tips so far guys.

Are you certain you're initially acquiring focus at all? I'd recommend going with center point or a single selected non-center point, getting that solidly on your subject, starting the focus routine at that point, then start shooting. If that doesn't improve your keeper rate then there may be something else going on.

EDIT: One other thought. You can "bump" the focus with AI Servo by releasing the shutter button or rear AF button (whichever you're using) then pressing again to re-acquire focus. It's a "bird in flight" shooting technique, but you might want to try it and see if it helps. For more on bumping AF, see here (post by a POTN member on another forum):
http://forums.dpreview​.com …rum=1032&messag​e=38105503

Using "all points" or "Auto AF" is exactly the wrong thing to do... That leaves it up to the camera to decide where to focus and it's going to choose differently than you would a lot of the time.

Why are you using AI Servo? It doesn't appear the subjects are moving?

With manual focus lenses, for street shooting we used to preset focus using the distance scale on the lens, before even bringing the camera up to our eye. Today with One Shot and reasonably fast lenses you can snap AF in so darned fast, that technique is hardly needed any longer.

I do agree that using a single point would be best... If using One Shot and not wanting the subject centered, you can still use the more sensitive center point alone, just once the camera locks focus and gives you focus confirmation (the green LED and/or the "beep", if you have it enabled), quickly recompose and take your shot. Focus will remain where it locked, unless you lift pressure off the button and cause the camera to refocus.

Using AI Servo, you need to keep the AF point right on the point where you want the camera to focus, unless you switch to using Back Button Focusingwhere you can start and stop the continuous focus with your thumb. AI Servo never locks... it constantly updates and even tries to predict subject movement. Stopping and starting AF with a back button is really the only practical way to do a focus and recompose technique in AI Servo mode.... The alternative if you want an off center composition is to pre-select an AF point other than the center one and keep that right on the subject. Yet another alternative is to frame your images rather loosely, shoot them all with center point only and subject centered, then crop the image later in post-processing to get the composition you want. Your 18MP 60D gives plenty of resolution to allow for some cropping.

But I still can't help but wonder if you even need AI Servo for those shots.

Oh, and your 60D is plenty capable. It's center point has some added sensitivity with f2.8 and faster lenses, but all nine of its AF points are good, "cross-type" that will work just fine (by comparison, 5D series and the Rebel series only have one cross type point at the center, so those models' outer AF points are less responsive). All xxD series cameras from 40D on and 7D have all cross type AF points. (Note: 7D has 19 points instead of 9 in the xxD models. The 45 point AF system in many 1D series have 19 cross type points, while the newer 1DX with 61 AF points will have 41 cross type.)

i don't understand why everyone is saying auto af is bad. i understand for street photography the subjects aren't moving too fast so center point may work well enough. however, when i was trying to shoot sports i had MUCH better luck keeping it on auto AF.

OP, i think you just need faster SS and more practice. it's definitely not due to your gear.

Shadowblade wrote in post #13995713
Really?

nice shot...but that eagle was really flying? 200mm on a 5dii...i'm surprised the wing tips didn't hit the lens

nikesupremedunk wrote in post #13999817
i don't understand why everyone is saying auto af is bad. i understand for street photography the subjects aren't moving too fast so center point may work well enough. however, when i was trying to shoot sports i had MUCH better luck keeping it on auto AF.

OP, i think you just need faster SS and more practice. it's definitely not due to your gear.

i think what everyone is referring to is the All-focus points...there's not a camera out there that's psychic and knows what you want in focus...so with so much in the scene it doesn't work...

op i think for the first shot you could've easily gotten away with just one shot...