Newbie photography question

Hi,
I am brand new to photography. Always being interested in photography, I just bought myself a Olympus C770 digital camera. I have always seen pictures of photographs were one thing in the photo is focused and clear, and everything else in the background is blurry.... how can I do this?
Thanks.

 

Set your aperture to it's largest opening, F2.8 on your camera, and let the camera select the shutter speed. Focus as normal and all will be well.

 

Here's a calclator for depth of field: http://www.dofmaster.com/dofjs.html

 

The depth of field chart will tell you what they said, except you need to make sure the distance from the subject to the background is outside the depth of field chart... example..... if Judy is standing right against a brick wall, the wall will be in focus. You have to have some seperation. The background must be outside the depth of field range. Hope that makes sense.

 

With a really wide aperture, the DOF can be very, very shallow. Using my 85mm lens at f1.8, I've shot portraits focusing on the person's eye and had the ear out of focus.

 

"Depth of field" is just the distance range in which things are in focus. The wider the lens opening, the smaller the depth of field will be. Caution: Lens aperture numbers are reverse! The larger the number, the smaller the lens opening. f16 is a very small lens opening. f2 is a very large lens opening.

Definition: f = lens focal length/lens opening

 

Then I stand corrected.

 

PS: Lachrymosa: Please don't cry!

 

ok a problem I been having when trying this.

In manual mode on my d50 with my I focus on an object and then try to widen my aperture. the listed aperture range on my 28-80mm lens is 3.3 to 5.6. if I set the focal length at 80mm and try to drop the aperture below 5.6 it will not go. Any Clue? I can run the aperture up as far as I wanna go (up to f40) however I cannot go below the f5.6 that my lens lists for the max aperture for the focal length my lens is currently at.

 

A lens cannot be opened further than wide open. For the Nikkor, this will be 3.3 when the lens is at 28mm. For the Sigma, this will be 4 when the lens is at 70mm. For each lens, as you zoom in [increase focal length], the lowest possible f number will increase.


If you wish to get to f numbers below 3.3, you'll need a different lens.

 

This is why people like myself prefer prime lenses (a single focal length). They can open to a much wider aperture than zooms. You have to pay big bucks to get a pro zoom that has a decent max aperture (like f2.8). I have a 50mm f1.4 and an 85mm f1.8. For my photography, that covers almost 100% of what I shoot.

Here's an example of a shot taken with the 85mm set at f1.8. His close eye is in focus, but his ear and hands are out.

 

Yea like people have said use a wide aperture. Only thing is, with your camera you are not going to be able to get that effect you are looking for very well compared with say an slr.