Looking for focus & recompose advice

[dwightdegroff]

Hey everyone, novice photographer here... total "Dad With A Camera" )trying not to be - sigh) looking for some advice.

So here's my scenario:

I routinely shoot my children in their natural environment(playing, running around, etc.) and during the winter months most of these shots occur indoors. I haven't, yet, purchased a better flash so I'm often using the on-camera flash of my D5100 and even still end up needing to keep the aperture fairly open (f3-5 range) even with a higher ISO so that I'm able to get correct exposure while maintaining a sufficient shutter speed to freeze the motion. 99% of the time I am using the "AF-A" focus mode and Auto Area mode.

Typically, I try to lock focus on the eyes and then re-compose(rear button focus, etc.) What I'm finding is that focus is no-longer sharp on the intended areas(face/eyes) after recompose.
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What I suspect is the culprit:

Due to the relatively-thin DOF, after re-compose the face(eyes) are no longer within the DOF and fall just out of focus.(referenced from http://www.thephotoforum.com/forum/...hallenges/262742-focus-recompose-problem.html)
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What I think might solve the problem, but am not sure is the best/most-efficient method:

- Change my focus area
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- "3D" seems like the best bet here in that it let's me select the initial focus point and then it tries to track the subject and changes AF points.
- "Spot" seems like it would ensure perfect focus, but I fear will take too long to keep changing the focus point while trying to keep up with my toddlers.​

- Find some way to increase my DOF(Better flash? Other?). My exposure seems to be dictating the DOF in a way that I can't get around without purchasing additional gear or boosting the ISO to a point that introduces too much noise.
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Do you have advice for me?

- How do you handle these types of situations?
- Will any of my ideas actually work to solve my problem?
- Do you have other/better ideas that will work for capturing extremely active subjects?
- Am I going about this in the wrong way?
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I'd love to hear your input and advice... thanks for taking the time to read my novel of a post.

 

[DiskoJoe]

Try using a smaller aperture and see if they are in focus better. Try f8 to begin. If its during the day you shouldnt have a problem and should be able to get really fast shutter speeds like 1/1000 or faster. Kids are hard to keep up with.

 

[The_Traveler]

Use a DOF guide (DOFmaster.com) to understand what your working DOF is for your lens and subject -camera distance, then adjust your shooting habits to match. If your camera allows auto-iso, that might be your best friend.

There is no magic answer short of general anesthesia for the children.
You will have lots of non-winners with short distance shots (very small DOF) using a slow lens and an on-camera flash.

 

[TheBiles]

Use back button AF. Also, try AF Servo mode so that you can recompose while maintaining focus.

 

[analog.universe]

Focus and recompose works better as your focal length gets longer. For wider shots, using autofocus, I'll usually select a single focus point and use that. You'll get faster at switching them if you do it a bunch. Often though, I'll actually focus these shots manually. With a lens that likes to be manually focused, and a good focusing screen, I get more keepers in manual for short focal lengths. My camera is also somewhat limited in the AF dept though, 9 points only.

 

[dwightdegroff]

Try using a smaller aperture and see if they are in focus better. Try f8 to begin. If its during the day you shouldnt have a problem and should be able to get really fast shutter speeds like 1/1000 or faster.

Thanks for the advice, DiskoJoe. Smaller aperatures("f/8 and be there", anyone?) do works very well, I agree, if I'm outside or in an exceptionally sunny room, but I don't often find enough indoor lighting to allow for f8 and 1/1000 shutter speed, even if I crank my ISO. I will continue to try to keep an eye on my aperature(and thus DOF) to see what I can eek out in these situations.

Use a DOF guide (DOFmaster.com) to understand what your working DOF is for your lens and subject -camera distance, then adjust your shooting habits to match. If your camera allows auto-iso, that might be your best friend.

Thanks for the DOF link, Traveler. Maybe just taking a few steps back to "eek" out some extra DOF would help me out in these scenarios, too. I suppose I can always crop later. When the going gets tough/crazy with my kids I will pop auto-ISO on, though I've been trying to keep it on manual most of the time so that I get comfortable adjusting it manually to get the exposure I really want.(clearly that's not working great for me, yet - Ha!). Thanks again for the link.

Focus and recompose works better as your focal length gets longer. For wider shots, using autofocus, I'll usually select a single focus point and use that. You'll get faster at switching them if you do it a bunch. Often though, I'll actually focus these shots manually.

Analog, thanks for the pointers. It goes along with what Traveler was saying. Why would focus and recompose work better as my focal length gets longer though? Don't I achieve a larger DOF by using a shorter focal length? Hmm... :meh: ... Whew... manual focus on my 2-year-old... maybe it's a practice-makes-perfect scenario. I'll have to give it a shot... it's going to be bad for a while. I'm lucky if I can manually focus on adults doing their thing. I do agree that I will likely get faster at switching my focus points if I do it more regularly and will find out which points I end up using the most based on my (lack of?) techniques, etc.

Thanks again for the advice everyone - good food for though.