Depth Of Field

[MDB]

I have a Fuji S5100 and I want someone to tell me what I can't achieve desired depth of field. I can shoot wide open or stopped down and the depth of field basically doesn't change. Is this something to do with a particular zoom setting or a p&s problem. What causes it?

[Ron Lacey]

Pretty much an issue with most non SLR digitals. The problem is the relatively short focal length of the lens, the shorter the lens the greater the DoF at any F stop. You can maximise the effect by stopping down all the way, zooming in, being as close as to your subject as possible and having a background that is as far away from your subject as possible.

HTH
Ron

[MDB]

So when you zoom in you shorten DoF...right?...what if I were to shoot a person at 50mm at 10' 5.6 and shot the same person at 50mm from 30' 5'6? What should the difference be? What if I shot the person from 30' at say 200mm at 5.6? This would shorten the DoF correct?

[MiriamJ]

Either moving in closer or increasing the focal length will decrease the DOF.

Of course both of these will increase the size of your subject in the photo.

If you have the subject framed in your photo the way you want and you want to decrease the DOF, you still have the 2 options Ron mentioned.

One is to move the background further from the subject, or the subject from the background, whichever is easier.

The other is to put the camera in aperture mode, (A), and increase the size of the aperture. (Don't forget, to make the aperture larger, you'll need a smaller F stop number. That is, f2 is a larger aperture than f5.6, and will give you a shorter DOF.

As far as backing up and increasing the zoom, unfortunately, when you back up you increase your DOF considerably.

To see how much difference distance makes, try putting your camera in macro mode, and shoot a flower close up, then in regular mode shoot the flower and it's surroundings. Close up, especially if the flower is really small, you may have trouble getting the whole flower in focus. Further back, you'll get the flower, and unless you have a far-away background, and/or a large aperture, you'll get the flower and pretty much everything around it in focus.

[MDB]

I think I understand better now. Thanks Ron and Miriam, I really appreciate you sharing that with me. Wonder how long that would have taken me on my own? You're right I never would have got it.

[Ron Lacey]

You can maximize the effect by stopping down all the way,
Ron

You're welcome MDB, btw what I said above should have been you can maximize the effect by opening up the aperture not stopping down, my fingers sometimes get ahead of my brain :).

Ron

[MDB]

aaahhh it really makes more sense to me now...
don't worry Ron I mess up all the time when it comes to typing...I'm the same way...my fingers and my brain both have a mind of their own...but thanx buddie I appreciate the help..

[Kevin]

Where the increased dof can be beneficial on a P&S is when you're doing macros. I know a lot of people who still prefer to do their macros with a point and shoot.

What you initially described and also the horrible shutter lag are the two things that ultimately drove me back to SLRs.