Help with focusing?

[ayeitsrickaye]

Exif:
Camera Nikon D80
Exposure 0.017 sec (1/60)
Aperture f/5.6
Focal Length 200 mm
Focal Length 201.6 mm
ISO Speed 200
Exposure Bias 0 EV
Flash No Flash


For this one i was trying to focus in on the ants in this tree we have in the backyard, but. i seem to not be able to focus them no matter what i do. I lowered aperture and i zoomed in a bit too. I think this would be easier with a macro lens, but sadly enough i do not have one yet :[

all critiques are appreciated guys <3 much love

[Doug Sundseth]

With that camera, aperture, and focal length, and assuming that your focal plane to subject distance was around 4', your total DoF was about 0.02' (around 1/4"). When your DoF is that shallow, you will often need to focus manually, especially when you have a contrasty background with significant depth, as here.

Also, it's a bit hard to tell, but you might have a bit of motion blur as well in this shot. If you're going to shoot at 200mm (300mm in 35mm equivalent) at 1/60 second, you'll need to have really good technique to keep the camera stable enough to get a sharp shot.

[JFSanders]

A tripod is really a necessity in this situation. As Doug said close down your aperture as you go up in focal length or your DOF is going to become razor thin. Also going up in focal length will make your distance to subject more critical as well as the DOF will be a 1/3 in front and 2/3 in back of your focus point. A true macro lens will make it easier to get the image but it will also make you work harder to get in the sweet spot and this will usually require a focusing rail as well as a strong tripod. Then you have the added problem of the subjects being quite small and moving relatively fast through the frame. Try using a off camera flash set to rear curtain mode so that the ambient light will expose the background and the flash will freeze the little bugs.

Jim