Depth of Field

Tkraz · Aug 20, 2004

Right first of all , I am aware of what this infact is, but my problem is that I am not sure how to go about creating such an effect.

I have a Kodak point and shoot, but it has features to adjust Aperture and Shutter Speed in the manual settings.

Having googled and been pretty unsuccesful, I was wondering if anyone could maybe help me with some basic steps or tips on how to create such an effect with the camera I have, if such a thing is possible?

StvShoop · Aug 20, 2004

use a small f-number (which corresponds to a large aperture)

and make sure the distance between foreground and background is larger than the distance between camera and foreground. not sure how close to that ratio the distances actually have to be, but it works for me most of the time.

Tkraz · Aug 20, 2004

Right, so there is just a level, or ratio of distances along those lines where it just seems to click you mean?

Rather than it being down to adjusting anything or any specific technique in actually taking the picture?

Thanks mate

deb · Aug 20, 2004

The use of dept of field is to distort objects in the foreground and background and emphasize the subject, with will appear sharply focused in the photo.

If you use a small aperture (large f number) you will get more consistent sharpness in all areas of the photo. If you use a large aperture (small f number), objects in front of and behind the subject on which you focused will be blurred.

To test, take a pictuer of a friend standing a few feet in front of a shrub holding a flower arms length in front of him/her. Take one shot with a small aperture with a longer shutter speed, take the other shot with a large aperture and shorter exposure time. The second photo should render the subject clearly focused and the flowe and shrub as "circles" of light or color as opposed to focused objects.

ksmattfish · Aug 20, 2004

check out

http://www.thephotoforum.com/forum/viewtopic.php?t=3362

Tkraz · Aug 20, 2004

Aye Im familiar with what it is and the basics of it, was just wondering if anyone could lend some tips as to how to creat the effect really.

Bit new to all of this and Im still picking it up :wink:

deb · Aug 20, 2004

What do you mean "create" the effect? Are you trying to mimick depth of field by editing digital images or are you trying to use depth of field to make a subject stand out in a picture you are about to take?

You can mimick the effects of depth of field in photoshop by selecting the background and applying a blur filter.

To use depth of field in composition, you use a larger aperture opening and a shorter shutter speed.

Tkraz · Aug 20, 2004

Sorry , I simply mean to use DOF in composition, apologies if my wording is slightly clumsy

Thanks for your help, I'll give that a go :thumbsup:

deb · Aug 20, 2004

No problem. Hope it helps.

ksmattfish · Aug 20, 2004

Tkraz said:
Aye Im familiar with what it is and the basics of it, was just wondering if anyone could lend some tips as to how to creat the effect really.

I am confused. Are you asking for suggestions for using a short DOF and/or a long DOF?

Tkraz · Aug 20, 2004

Either at the moment mate, Im totally new to all this and need a bit of help just testing out how to use it in a composition.

ksmattfish · Aug 20, 2004

Well, common uses would be short DOF for portraits, and long DOF for landscapes. But experiment and bust up those common assumptions. :lol:

Take 2 shots of each of your next dozen or so compositions, 1 with short DOF, and 1 with long DOF, and you'll figure it out a lot faster than anyone here could explain it to you. Try out some medium depth DOF while you're at it.

markc · Aug 21, 2004

If you are using a zoom lens, you might not be able to get a very distinct shallow DOF. They often don't open up to very wide apertures. To help exagerate the effect, shoot at long focal lengths. They give the effect of a shorter DOF.

Goofup · Aug 21, 2004

Im totally new to all this and need a bit of help just testing out how to use it in a composition.

I'm confused too about exactly what you're asking. How do you use it in a composition? Well, that depends on what you want the end result to look like (I don't think DOF falls under "composition" any more than under/over exposure does).

Anyway, DOF is controlled by 2 things, not just 1. 1- How far away is the focus point? 2- What aperture are you using? So, A) the smaller you close down the lense (large f-numbers) and/or the further away you focus the deeper the DOF and the more everything near and far is sharp. Likewise, B) the more open the lense and/or the closer the focus point is the shallower the DOF and the more the subject is sharp and the background is fuzzy.

Now that you know how to "create the effect", how do you "use it in a composition"? That's your desision- it's your picture. Do you want everything sharp or do you want the background fuzzy?

Finally, I have this link bookmarked. Put in some figures and you can see what it will take to create (or not) DOF, and what will happen to the DOF using various focus distances and apertures:

http://www.shuttercity.com/DOF.cfm