Focus / speed issues

sworks

sworks

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Mark
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I took some photos of my son learning to ride his bike today, I had to be quick as he is a bit embarrased that up until now he has had no interest to learn but all his friends are giving him grief. The focus is rubbish (as were a lot of my other shots today?) I seem to have focused on his jumper rather than his face but even that isn't great. He was coming towards me and the settings were :-
Tv mode
iso 100
f4
shutter speed 1/60
@ 72mm
Is it the shutter speed at fault?
 
Errr yes - but its your fault - you selected shutter priority and dialled in 1/60th!
 
I thought the speed was wrong as I didn't have time to change the settings, as it was a quick snapshot - Any suggestions if I get another try tomorrow?
 
Faster shutter speed - 1/400-500th should nail it.

Remember that probably means a higher ISO too.

If you had a camera with a "sports mode", you could have used that ;-)
 
I tried 1/400 @iso 800 and it was way under exposed. I'm getting confused, I thought getting the exposure level in the viewfinder would have given the correct shutter speed????
 
The shutter speed you need depends on what your doing and shooting, if you shooting a still object on a tripod for example then u can have a slow shutter speed, if it's not too bright of course but if your taken moving shots, i.e your son on a bike, a dog, a plane etc you want a faster shutter speed or pan in time with the movement, but as you say high shutter can mean dark photos so increase iso, lower apature.
 
With moving subjects you should also set camera to AI Servo. This allows the focus to "track" moving subjects.

When setting the shutterspeed there are two points to remember.
High/fast speeds freeze the subject and if set high enough can make it look stationary.

Low/slow speeds allow movement into the shot. With this you need to follow the subject (panning) and takes a bit of practice. Get it wrong and you can get camera shake.

Try somewhere in the middle about 320/400th. This can give just enough movement and should eliminate any camera shake.

Set camera to Tv and ISO accordingly to let camera determine the f number.
 
sworks said:
I tried 1/400 @iso 800 and it was way under exposed. I'm getting confused, I thought getting the exposure level in the viewfinder would have given the correct shutter speed????
Click to expand...

Metering and setting exposure is far more complex than that. Getting the meter needle level/centred doesn't mean a thing, other than whatever you are aiming the metering area at will be rendered as a mid tone, equating approximately to 13% grey. If the thing you are metering from is not 13% grey then your exposure will almost certainly be wrong.

I doubt very much you need to go as high as 1/400 or 1/500. I'm sure you could get an acceptable result at around 1/250, although higher would be better, but not if it is at the expense of IQ for other reasons, like insufficient DOF or unacceptable noise.

If you were shooting in sunny conditions then 100 ISO, f/4, 1/1600 would be about right. You must have been shooting in some pretty miserable conditions for 1/400 at 800 ISO not to work, especially at f/4. That exposure would suit light levels 5 stops dimmer than bright sunshine, so if that was underexposed, where on earth were you shooting? Indoors? In a forest? After sundown? Are you sure you were still at f/4? Did you have a CPL or ND filter fitted?
 
Sorry to gatecrash a thread but, would setting the camera in Av with the widest aperture for the lens selected not automatically give the fastest shutterspeed possible for a given ISO. Then raise the ISO until your shutterspeed is fast enough enough for the conditions. If your camera is not focusing automatically on his face simply select the focus point required.
 
Ian, you would still need to have your metering pattern chosen with some thought and be prepared to dial in some exposure compensation to suit the subject/scene and metering. Flash is also an option too, if needed. There are plenty of ways to skin this cat, but if the basic exposure is (badly) wrong then it doesn't much matter which approach you take.
 
Ahhh the dreaded metering, I have read many of your explanations an have found them really informative Tim. I guess its just trail and error and the and getting out taking the pictures to gain the knowledge of what to do.
 
Donki said:
Sorry to gatecrash a thread but, would setting the camera in Av with the widest aperture for the lens selected not automatically give the fastest shutterspeed possible for a given ISO. Then raise the ISO until your shutterspeed is fast enough enough for the conditions. If your camera is not focusing automatically on his face simply select the focus point required.
Click to expand...

^
 
Donki said:
No, no, I mean its a matter of putting what you say into action and understanding how metering works.
Click to expand...

I know. Only teasing. I did use the biggest smiley I could find. :D

Mostly the way I learn things is by research and experimenting. Find out what works for you. Then carry on.
 
Thanks for the help, by getting it wrong I'm still learning :) It was around 6.30pm and had been a very sunny day and I was in the garden. I took some yesterday and got better results.
 
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