9 Point Focus Woes

[christiehw]

Hello,
I am very very new to digital photography and am having an issue using the 9 point focus with my Canon XTi. I am typically taking photos of my very active toddler in our home. The lighting is low so I am almost always in AV mode with an 24-70mm lens set to f-stop 2.8 and ISO at 1600 to let in as much light as possible. I haven't taken the full 'Manual' setting leap yet! Anyway, auto focus always seems to focus on everything I don't want it to, so I have been using the 9 point focus. The problem comes in that my child is constantly moving, so I am constantly having to change the 9-point focus point to focus on his eyes. It seems that the wide open aperture makes it so that my focus has to be spot-on one eye or in between his eyes with little room for error. I have tried doing the focus on the eyes and then recompose method, but that takes time and by the time I am done doing that, he has moved again. I need to click the shutter immediately to get the picture and not constantly be messing around with the focus. What to do in this situation? Am I missing something? How do people get great in-focus sharp shots of a moving squirming little guy in low-light situations? Thanks so much in advance for your help!
~Christie

[ttosifa]

Hi --

I struggled with this for a long time. You are shooting your kid like you'd shoot sports. You'd think they are similar, but they are not. With kids, your mostly have to be close. There's just not enough room inside a house. Plus often you want to be close, perhaps for safety reasons.

Since you must be close, you have a very narrow DOF at wide open apertures. As you said, you must be spot on or you are out of focus.

So what you really need is a narrow aperture (bigger f number) to give you more DOF up close. The only way (that I know of) to get this is by adding flash to the pictures. That will get you more light so you can close down the aperture. A side benefit is that flash is very fast (faster than 1/1000) so it will often freeze motion even at relatively low shutter speeds. Of course, I highly recommend off-camera flash.

http://strobist.blogspot.com

And I think manual is the way to go, even if you get a flash. TTL just slows everything down, and it annoyed my daughter and made her blink too much.

[OsmosisStudios]

Seems like a DoF shift.

Your f/2.8 gives you a fairly shallow depth of field, which your toddler is likely running through rather to-and-fro. The camera cant keep up.

[jprime84]

I know that on my XSi you can manually focus and it will beep and light up the focal zones as they get in focus if you hold the shutter button down halfway. You may find it easier to just keep a hand on the focus and make adjustments on the fly, and quickly take those shots where you get the "in focus" notice in a zone near your childs face (or wherever you want to focus).

Other than that, flash is probably the next best thing as it would allow you a larger DoF so your focal point would not need to be so precise.

If you stick with auto focus, set it to the mode that constantly adjusts focus not once per shot.

[christiehw]

Excellent! Thank you so much for the great thoughts!!! It is crazy how much I still have to learn. But, I am off to practice your great tips....Thanks again!

[mizuno]

Originally Posted by jprime84

If you stick with auto focus, set it to the mode that constantly adjusts focus not once per shot.

If you are taking multi-shots at once, can the autofocus be set to refocus after each shot throughout the multi-shot? Thanks.

[jprime84]

Yeah, i think you either set the auto focus mode from single shot to AI Auto or AI Servo

[KimberleyPhotography]

If you want to stay on the natural light side of things I would suggest shooting primerily in a room in your house that has large windows if at all possible. If you've ever been to Audrey Woulard's blog, she uses a very small apeture and still manages to get the eyes tack sharp but its because she uses ALOT of light! But she also has year of experiance under her belt so dont be too hard on yourself kids who never stay still can be frustrating!

[agresbach]

Originally Posted by KimberleyPhotography

If you want to stay on the natural light side of things I would suggest shooting primerily in a room in your house that has large windows if at all possible. If you've ever been to Audrey Woulard's blog, she uses a very small apeture and still manages to get the eyes tack sharp but its because she uses ALOT of light! But she also has year of experiance under her belt so dont be too hard on yourself kids who never stay still can be frustrating!

just checked her blog out and she has some amazing shots on there. do you know if she has a typical aperture range she uses for her close up portraits to get that dramatic drop off effect and still keep BOTH eyes locked on so well (experience does play a big role as well as lots of light i know). I really like the drop off i get with 1.8 but very difficult to get both eyes in focus unless the person is looking RIGHT at you (so both eyes are essentially the same distance from the camera). I was instructed by someone else to stay in the 2.8-3 range as a min for these kinds of shots

[KimberleyPhotography]

Originally Posted by agresbach

just checked her blog out and she has some amazing shots on there. do you know if she has a typical aperture range she uses for her close up portraits to get that dramatic drop off effect and still keep BOTH eyes locked on so well (experience does play a big role as well as lots of light i know). I really like the drop off i get with 1.8 but very difficult to get both eyes in focus unless the person is looking RIGHT at you (so both eyes are essentially the same distance from the camera). I was instructed by someone else to stay in the 2.8-3 range as a min for these kinds of shots

I don't know how she does it, but she claims that most shots are takend at 85mm f1.6.