Struggling with AF

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psf150

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paul
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Hi everyone

I've been struggling to take sharp enough indoor pics that I'm pleased with of my toddlers. Have upgraded camera body to a 40d, and lens to a 24 - 105 l, but still not that good.

Occasional shots are very sharp (especially when using a flash), so suspect its not a problem with camera or lens but user error!

Any tips?
 
Can you tell us what setting you are using, ie shutter speed, iso etc
 
One thing I've learned from my various attempts with my kids is that they are a very hard subject - take a jet or a car, they go in a predictable line, even birds in flight often do - but toddlers, they are like herding cats!!!

Post some stuff up, I'm no expert but I've made enough mistakes to be able to help (maybe!)
 
psf150 said:
Hi everyone

I've been struggling to take sharp enough indoor pics that I'm pleased with of my toddlers. Have upgraded camera body to a 40d, and lens to a 24 - 105 l, but still not that good.

Occasional shots are very sharp (especially when using a flash), so suspect its not a problem with camera or lens but user error!

Any tips?
Click to expand...

User error, yes probably, though that's a harsh judgement. Moving subjects in low light indoors is hard at the best of times.

It's more than likely focus issues or movement blur, perhaps both, but knowing that doesn't make it any easier to fix, unless you can avoid both by nailing them to the spot ;)

Need to post an example.
 
Agreed that it's possibly 'user error' but as others have said, kids indoors are a very tricky subject to get right at best of times.

'User expectation' always springs to mind as (if you're like me) I tend to put a fair bit of thought into landscapes or birds but when it comes to photographing my kids I just snap away.
 
I suspect that without flash your not getting enough light with a F/4 lens to get a fast enough shutter speed? I guess the only way would be to bump up your iso a lot higher to compensate (which in itself will reduce sharpness) or maybe buy a cheap 50 1.8 lens for your indoor shots.
 
Thanks for taking the time to reply so far guys.

Having look at a few dissapointing shots they were mostly arround the f4 / f5 mark with shutter speeds of 1/30 or 1/60. I'll post some up later.

I've also been looking through some old threads and I think I might have worked out part of the problem.

My main issue was the centres of the images were not that sharp, i.e. noses and eyes. I've just read that by setting the camera to use the central focus point only, and by having the af drive set to AI Servo, should help?

And having just fired off a couple of quick test shots this seems to be the case?
 
The 24/105 is a good lens but you'll need to use 1/100 at least to avoid camera shake unless you have very steady hands, so the speeds you have used will have probably induced blur from the camera. Unless your kids are staionary their movement will also induce blur if you shoot below probably 1/150 or faster (havent taken any kid shots for a while but my moggy cant be captured below 1/250). Centre point and servo focus definitely. One last thing, a faster lens might help but then you'll have even less dof and that induced loss of critical point focus unless you are spot on.

Matt
 
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MatBin said:
The 24/105 is a good lens but you'll need to use 1/100 at least to avoid camera shake unless you have very steady hands, so the speeds you have used will have probably induced blur from the camera. Unless your kids are staionary their movement will also induce blur if you shoot below probably 1/150 or faster (havent taken any kid shots for a while but my moggy cant be captured below 1/250). Centre point and servo focus definitely. One last thing, a faster lens might help but then you'll have even less dof and that induced loss of critical point focus unless you are spot on.

Matt
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+1

kids move...a lot! and they do it quickly most of the time so you'll need to push your shutter speed far higher than 1/30 or 1/60. at those sort of speeds with the 24-105 you'll probably be getting both motion blur from your subject AND camera shake. the IS on the lens can compensate for camera shake but not movement on the subjects side.

f/4 on that lens should be pretty good in terms of sharpness, so try bumping your iso higher you'll be looking to be at around iso 800 and higher if you're using natural light. or add flash to the equation and you'll have the option of lowering your iso(for increased image quality) or stopping down your aperture (for inceased depth of field).

i just looked in bridge and the last shots i took of my niece indoors were taken on a 5d at iso 3200 with apertures between 1.8-2.8, and shutter speeds ranging from 1/60-1/125.

1/60 on the 5d with a 50mm lens is boderline for what i personally can handhold but there is motion blur in a lot of those shots. as the shutter speed increased my number of 'keepers' went up

in low-light i live in the center af point because of it's increased sensitivity over the outer points, and almost always have af set to ai servo with back button focus enabled through the custom functions.
 
Thanks again guys. Very good pointers.

Lexie - can I just check what do you meant by "back button focus"
 
You can separate the autofocus from the shutter button using the custom functions. Focus can be locked using the back button marked *. On my 5d it's the CF marked shutter/AE lock button, with the option 'AE lock/AF' selected, this means AE lock is controlled by half pressing the shutter button and AF is controlled by the '*' button. Your 40d should work in a very similar way.

A lot of people use this set up because it means you can set AF to AI servo and hold the '*' button to track your moving subject, meaning your shutter button is free to just take the shot. There should be loads of info on the forum which should explain it better than i can.
 
I would always go with "zone focus" for this type of shot. Set the approx "ball park" focus distance and you can then shoot with a fairly narrow aperture (f/8, f/11, f/16, f/22) without worrying about "exact" focus. You will need flash though to be able to do this indoors.
 
Thanks again guys. I will try all of the suggestions.

Its funny isnt it, I've always rated myself as a half decent amateur photographer, as over the 25 years that I've been dabbling, I've taken a number of shots over the years I'm quite proud of.

The reality would appear to be I know jack ******, and I've been lucky all those times!

Maybe I should start doing the lottery.

Anyway its time to step up a gear.

Watch this space!

And genuinely, thanks for everyone who took the time to reply
 
psf150 said:
Thanks again guys. I will try all of the suggestions.

Its funny isnt it, I've always rated myself as a half decent amateur photographer, as over the 25 years that I've been dabbling, I've taken a number of shots over the years I'm quite proud of.

The reality would appear to be I know jack ******, and I've been lucky all those times!

Maybe I should start doing the lottery.

Anyway its time to step up a gear.

Watch this space!

And genuinely, thanks for everyone who took the time to reply
Click to expand...

just spend too much time on forums like this and the technical stuff is picked up in time lol
 
All I can do is back up the advice already given here. 1/30sec isn't fast enough to get sharp images of fast moving little people and you might even be getting some camera shake creeping in too. I'd suggest using shutter speeds of around 1/200 minimum, that should be enough to eradicate most if not all motion blur.

You can open the aperture up and use flash and if that's not enough then up your ISO to a sufficient level. This will increase image noise but assuming your not intending the photos of your kids to be going on the front cover of Vogue or on billboards I wouldn't worry about that too much.

My last tip is shoot in raw or raw+jpeg. Raw files will clean up any noise much better in photoshop etc than jpegs.
 
lexie said:
You can separate the autofocus from the shutter button using the custom functions. Focus can be locked using the back button marked *. On my 5d it's the CF marked shutter/AE lock button, with the option 'AE lock/AF' selected, this means AE lock is controlled by half pressing the shutter button and AF is controlled by the '*' button. Your 40d should work in a very similar way.

A lot of people use this set up because it means you can set AF to AI servo and hold the '*' button to track your moving subject, meaning your shutter button is free to just take the shot. There should be loads of info on the forum which should explain it better than i can.
Click to expand...

Cracking advice from you all, thanks from me aswell. Now I need to try and understand the above! :/
 
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