Why do point and shoots get out of focus so easily.

[David Lim]

For consumer cameras why does it get out of focus so easily and at what level (price point) of DSLR camera does it take to get a running shot and not get out of focus (I assume that with a budget camera in video mode there will be a bunch of issues). Is there any specs that can generally tell how well the camera will do for focusing in fast pace shots?

 

[Tinderbox (UK)]

Contrast detection has problems with the target get closer or moving away from the lens, phase detection has no problem, though contrast detection can be more accurate on still objects in good light, phase is better in low light, it`s swings and roundabouts.

How about the new mirror-less cameras that use both phase detection and contrast detection, the Nikon 1 system camera`s entry level models can be very cheap.

John.

 

[David Lim]

thanks

 

[KmH]

Contrast-detection AF is often slower than phase-detection AF.
Did you know that most pros that shoot video or movies with a DSLR manually focus the lens because they know they can't rely on auto focus?
That's also why 3rd party equipment makers offer 'follow focus' attachments for DSLR camera lenses.

Auto focus is not a be all to end all and there are several fairly common situations where AF won't work well.

 

[David Lim]

So high end cameras specifically for video making uses phase detection? I see a lot of video cameras have focusing issues where it takes a few seconds to focus correctly, using phase detection eliminates that problem entirely?what else do you guys look for when choosing a camera for videos.

Are there any specs that are bad for video but good for photography or vice versa. Is it possible to have a good camera for video and photography or in a professional situation its better to get one camera for video and another for photos?