Subject coming towards you, how best to focus

Could I get some pointers on how to get good focus when the subject is moving towards you, like a bride & groom striding down the aisle at the end of the wedding ceremony, or a child running towards you, etc? I know that's a very wide open question with endless variable (how fast? how big is the subject?) but looking for the basic pointers. THanks!

Aside from a few technical details, put the camera in AI Servo mode, multiple shots. Set to center focus point. Target your subject and hold the focus button down for the entire time (ie entire duration of bride walking or kid running). Hit the shutter whenever you want a picture.

Next thing you know, you'll be a sports photographer

Dave

tracknut wrote in post #9721520
Aside from a few technical details, put the camera in AI Servo mode, multiple shots. Set to center focus point. Target your subject and hold the focus button down for the entire time (ie entire duration of bride walking or kid running). Hit the shutter whenever you want a picture.

Next thing you know, you'll be a sports photographer

Dave

Dave, if I'm using back button focus I need to hold that button in?

If there is a sporting event for eating chocolate, I'm there.

Michelle Brooks Photography wrote in post #9721622
Dave, if I'm using back button focus I need to hold that button in?

If there is a sporting event for eating chocolate, I'm there.

Yes, whether its the back button or the half-press of the shutter button, you hold it down continuously during the entire process. So thumb mashed down for 10 seconds (or whatever it might be), and then index finger pushing the shutter when you want a photo (probably not solid shooting for 10 seconds...)

Chocolate, ey? I may just join you to assist on that one!

Dave

Most definitely AI Servo mode. I don't have the 50D, but if there is a way to change the tracking sensitivity under a custom function, then make it a bit slower. I agree w/ center point focus, as well.

asysin2leads wrote in post #9722559
if there is a way to change the tracking sensitivity under a custom function, then make it a bit slower. I agree w/ center point focus, as well.

Is that because you actually need a slower shutter speed when the subject is coming towards you as opposed to crossing your vision from one side to the other, or does the tracking sensitivity have nothing to do with that? I read that (about the slower ss), but I haven't been able to find any info giving an idea of possible shutter speeds for certain situations (ie, bride and groom coming down aisle). The little voice in my head starts screeching "Are you nuts?!?! Slow the speed???"

Michelle Brooks Photography wrote in post #9722687
Is that because you actually need a slower shutter speed when the subject is coming towards you as opposed to crossing your vision from one side to the other, or does the tracking sensitivity have nothing to do with that? I read that (about the slower ss), but I haven't been able to find any info giving an idea of possible shutter speeds for certain situations (ie, bride and groom coming down aisle). The little voice in my head starts screeching "Are you nuts?!?! Slow the speed???"

no. Tracking sensitivity has to do with if something steps between the focus point and your intended subject. If there's a custom function to change this, you can control how long it takes before the camera shifts focus from the previous subject to the new, obstructing subject. This is available on the 1-series and 7D.

For moving subjects, you always want the fastest shutter speed possible. Experience or mathematical calculations will tell you how fast before the motion blur becomes unacceptable to you.

On the 50D, I would consider NOT using the high fps setting on objects coming towards you (or away). I do not believe there is enough time in between shots to refocus. I have tried several times and found that impossible. The lower fps setting works better.

Tracking sensitivity is limited to the 1 series and 7D AFAIK.

I would definately stick it in AI servo. And probably stick to 1/100 or shorter to freeze any motion, bearing in mind that they are only walking there is unlikely to be huge amounts.

Focus point - centre (if it suits what you want to capture). Centre point is nearly always a high precision focus point on anything higher than a 40D.

As for single shot, low FPS or high - i think it depends on your style of shooting.