Focussing using NIKON D5100/D3200

Mark-Anthony

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Hi All

I love playing around with my cameras, taking pics on a regular basis. However just lately I've been wanting to try videos. after a recent trip to NYC, I found that both my cameras were a bit of a nightmare in video mode using my sigma lenses.

I have the d5100 and the d3200. and have sigma lenses such as the 18-50 f/2.8, 50mm f/1.4 and 10-20mm lens.

Main issue I'm having is when trying to capture something like a street view or lets say a street performer dancing. the auto focus is all over the place. constantly focusing on the movement leaving blurred video. I've tried it in AF-F Mode and AF-S mode and also in MF mode. I've even tried changing the focus points from the 3d 11 point mode to full pic.

am I right in thinking that this is normal, or am i hoping for a video camera quality whilst using a d-slr?

All i'm after is for it to stay focused on the subject it's recording whilst on a tripod and not keep focusing or going out of focus when on MF.

HELP!
 
This normal because of how AF works in these cameras. Everything is done by manual focus- note that the big movie productions employ focus pullers for their shoots i.e. camera man and an assistant per camera whose job it is to make sure the relevant things are in focus within the shot.

Quality far exceeds any camcorder but camcorders are much easier to operate- take your pick. Producing great footage from a DSLR is a skill in itself but it is not rocket science- just takes hard work.
Manufacturers are trying to improve AF in them for movies- Canon's 70D uses a hybrid AF system but MF is still the only reliable way. There are tools out there to help with keeping focus.
 
Why's it going out of focus in Manual Focus mode? Do you mean the performer is moving out of a relatively shallow depth of field? In that case, smaller aperture, or pull focus. Or are you changing the zoom - still lenses are not parfocal - the focal length changes the distance to the focus point.

AF is hardly ever used in professional video.
 
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