what is the trick to get focus whilst recording HD video on the nikon d3100?

[jxharding]

i'm not a complete noob when it comes to photography and videos.
i toyed with the idea of getting a nikon D3100, because it can do HD video, and i thought i didnt have to buy a HD video camera as well.
was fortunate enough to borrow my friends' D3100 for short time, and i really really battled to get focus whilst recording video.

couldnt even get my jack russel to gain focus, whilst it was standing on grass with absolutely nothing surrounding the dog. but im not giving up hope.
i'm blaming my inadequacy. this has got to work i think

is there a trick to work the video properly? any suggestions? anyone else find problems?

 

[B.K]

While in live view, press the "I" button, the scroll to the option "Focus Mode", in there should be AF-S, AF-F and MF, select AF-F, the go one option down to "AF-area Mode" and select either of the tracking options , I normally have mine set to Wide-Area AF.

That should give you auto focus


EDIT

I think with most SLRs that have live view, the camera supports two types of auto focus modes, the one is through the eye piece optics when taking normal pictures, and the other is on the sensor when in live view, so setting your auto focus option in one mode will not change the other.

 

[ponder]

i'm not a complete noob when it comes to photography and videos.
i toyed with the idea of getting a nikon D3100, because it can do HD video, and i thought i didnt have to buy a HD video camera as well.
was fortunate enough to borrow my friends' D3100 for short time, and i really really battled to get focus whilst recording video.

couldnt even get my jack russel to gain focus, whilst it was standing on grass with absolutely nothing surrounding the dog. but im not giving up hope.
i'm blaming my inadequacy. this has got to work i think

is there a trick to work the video properly? any suggestions? anyone else find problems?

If video is important to you have a look at the Panasonic GH2. Apparently it pawns every slr on the market when it comes to video.

But then again if video is that important to you it would be better to buy a dedicated tool for the job.