More info on depth of field

by Dustin Olsen

 

Need more blur? Go to: Filter > Blur > BINGO! Same with sharpening! But before we “Go to:” anywhere in Photoshop – we need to nail it the camera, first! Simple things such as adding blur or increasing the sharpness are things we can do before making it to Photoshop.

We Want More Blur?!

Get further away and zoom in.

A large aperture (i.e. –  f/2.8) will play a big part in how much we blur we can achieve in the camera. Prime lenses are great for this because they can get such a low f/stop number… but what about our affordable zoom lenses that only make it to f/4.5?? We need more blur in our background but our f/stop is maxed at out. So give this a try this:

1. Step back away from your subject/foreground.
2. Zoom in to achieve the same framing you originally intended.
3. Keep the same, low, f/stop number.
4. Meter your light for proper exposure.

Being further away from your subject will help increase the amount of blur in your background, and you will create what they call lens compression. When lens compression happens, you will notice that your background will appear closer to your subject than it actually is compared to if you were to take a wide angle shot of the same thing, up close.

 

We need more detail!!
Achieving that Deep Depth-of-Field can also be a challenge sometimes! You need your interesting foreground in focus just as much as you need the entire background in focus. So where do you focus?? You want to focus about 1/3 of the way into the photo… which is the lower third.

1. Frame your shot just the way you want it. Good composition and creative perspective will go a long way!
2. Consider the Rule of Thirds and focus where the lower third is in your shot.
3. Increase your f/stop number to around f/16-20 to ensure that from the lower third, and up, is in focus.

By focusing on the lower third, you are telling the camera that you want this area closest to the camera to be in focus! You don’t want to forget that! Your large aperture will take care of the rest of photo because it is responsible to get as much in focus as possible. It just forgets about the area closest to the camera if you were to focus anywhere else, except for the lower third.

 

We just took your existing knowledge about depth of field and we added to it. Little things like this can go a long way in making better quality photos.

 

If changes need to be made to this article, please let us know.

Comments from the I.P. Community

  1. Brian says

    Your large aperture will take care of the rest of photo because it is responsible to get as much in focus as possible.

    Shouldn’t that be SMALL aperture for greater depth of field? Small apertures have large f/stop numbers. For example, f/16 has an aperture that has half the diameter as f/8

  2. Jim (not Harmer) says

    to the people criticizing this article, remember that it is in the ‘beginner’ section.

    as a rank amateur with an Entry level DSLR (Nikon D40) I assure you this article is a massive help. As and when i have a grasp of how my kit, me and my camera can interact better to change the look and feel of a shot. Then I can worry about the minute details at a later point.

    For example, for me, zooming in and standing further back is counter intuitive (with a variable lens, the zoom will increase the f-stop to 5.6) and so should increase the depth of field (based on the theory of small f number = shallow DOF) and so i dont think i would have tried to stand further back and zoom.

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