Why is one person blurry in my pictures

[franklin]

Why is it when taking family photos one child is blurry. Last week I took a friends family photos outside. My camera was set on a tri-pod. They have 5 children and in each photo I took one child is blurry. What am I doing wrong? what is the best setting to have your camera on for fast moving children?
Please help me.
Thank you

[Matthias099]

Originally Posted by franklin

Why is it when taking family photos one child is blurry. Last week I took a friends family photos outside. My camera was set on a tri-pod. They have 5 children and in each photo I took one child is blurry. What am I doing wrong? what is the best setting to have your camera on for fast moving children?
Please help me.
Thank you

Can you post the picture so we can take a look at it? It's hard to suggest anything without having it seen.

[kirbinster]

Without seeing the photos it is hard to say exactly, but most likely you are shooting with the lens open too wide (a low f/stop number). When you do this you will have a shallow depth of field so that if one person is slightly forward or backward of the focus point they may be out of focus. You either need to be certain each person is in the same focal plane or use a larger f/stop number which will effectively give you more room for error by giving greather depth of field.

[RLucas]

All the above, plus if you have one child moving in to the frame, and one moving across the frame, depending on your shutter speed, the one moving across will appear more blurry.
Examples would help tremendously.