I Need Help Understanding Focus Points

[bleeblu]

I moved from a Fuji X10 to a Nikon D5100 and I'm a bit confused about the focus points in the viewfinder. Let's say I want to take a portrait shot at 50mm and want to off center the model's face. First, I would center their face and wait for the camera to beep, then off center it and shoot.

But why is it sometimes focusing on multiple points in the background or several points on the face? Can someone explain this to me in more detail please? Thank you in advance!

 

[timethief]

you need to turn off auto focus and choose single focus point.If you do shoot in just AF mode you need to change your Autofocus option using CSM because the default mode is for the camera to choose focus point for you, which is what is giving you trouble as the camera does not know what object is the subject. Now to change that setting, press MENU button and go to the CSM (Custom Setting Menu). Then choose first option (a Autofocus) and then select Single Point. Now you can select focus point by using Thumb Pad (Multi-selector button) and lock the focus point wherever you want using AF Selector Lock lever next to the LCD screen. This guarantees that the camera is focusing on your intended subject because you’ve told it in advance which of the 11 AF point to use for focusing. Make sure that the lever next to the LCD screen is switched to the L (Locked) position after you select your preferred focus point

 

[bleeblu]

Thank you! Now do I have to hold the shutter halfway down while using the thumb pad to select the focus. Sorry, my camera is not on me at the moment.

 

[timethief]

no. just press once softly to activate.

 

[KmH]

FWIW, all the info timethief provided is in the D5100 user's manual - pages 39-46.

There are 2 kinds of auto focus points - regular and cross-type. http://www.cambridgeincolour.com/tutorials/camera-autofocus.htm

Regular focus points detect edges in only one direction. some detect horizontal edges, some detect vertical edges.
Cross-type focus points detect edges in both directions. Cross typre focus points are more accurate than regular focus points.

The D5100 has Nikon's Multi-CAM 1000 Auto Focus module, so only the center focus point is a cross-type point.