Project 52, Week 10, Depth of Field (DOF)

Effective use of depth of field can add depth and dimension to a photo.  Depth of field (DOF) is the area of the scene that is in acceptable focus. 

• If you have a very shallow depth of field, only the subject itself will be in focus.  The area behind the subject will be blurry.  This is also referred to as "narrow DOF".
• If you have a deep depth of field, the entire picture will be in focus.  This is also referred to as "great DOF" or "extended DOF".

This can be more complicated than it sounds and takes practice to perfect.  There are 3 things that affect the depth of field:

1. Aperture - refers to the lens opening that allows light to enter the camera and reach the sensor (or film)
• the larger the aperture the shallower the depth of field
• The size of the opening is indicated by the F-stop; the larger the F-stop the smaller the opening.  [Think of this the same way you do fractions - 1/2 of a pie is bigger than 1/4, 1/4 is bigger than 1/8, and so on, just as an aperture of F-2 is wider than one of F-4 which is wider than F-8, and so on]
2. Distance - the distance between the camera and the subject
• the greater the distance between the camera and the subject, the greater the depth of field
• the shorter the distance, the shallower the depth of field
3. Focal length - basically, the distance from the lens to the sensor (film)
• the longer the focal length, the shallower the depth of field
• the shorter the focal length, the greater the depth of field
• wide angle lens (such as 21 - 35 mm) have a greater depth of field than telephoto lenses (greater than 70 mm) ["Normal" lenses are generally considered to have a focal length of 35 - 70 mm, usually 50 mm.]

Use a shallow depth of field to focus attention on the main subject. 

• This helps you to apply the composition rule Simplify.
• This is frequently used for portrait and nature photography.
• Usually you will want the subject to be in sharp focus, but you might try blurring the subject and having something else, perhaps a contrasting element, in focus

Use a deep depth of field to include all elements in the scene. 

• This is frequently used for landscape photography (but a shallower depth of field can also be effective).
• Don't make the scene too "busy" or your story will get lost.

Suggested Reading and Photographic Examples:

1. Depth of Field by Joe Hinshaw and Steve Anderson from School of Media Arts & Design, James Madison University; interactive depth of field tutorial
2. Depth of Field Explained by Steve Basiter and and Peter Bargh from ePhotozine; medium size article with pictures of camera settings
3. DOFMaster; calculators, articles, FAQs
4. To Blur of Not to Blur from Photography in Malaysia; article and photos
5. Effective use of hyperfocal focusing for wide angle landscape photos by Rod Barbee from Barbee Photo; article with photos and tables
6. Tutorials: Depth of Field from Cambridge in Color; an article including "Circle of Confusion" and DOF calculators
7. Depth of Field and Diffraction by Norman Koren from Norman Koren.com; article includes several tables, complicated formulas, and discussion of diffraction

Learning Videos:

1. Photography 1 on 1: Depth of Field by Mark Wallace from AdoramaTV; a 7 minute video
2. Photography tutorial - depth of field by Scott Muller from Total Image; a 4 minute YouTube video
3. Canon EOS - Getting Started: Depth of Field Photography from Cannon Australia; a 3 minute YouTube video
4. Understanding Depth of Field in Digital Photos from Dummies.com; 2 minute video
5. Lens Focal Length by Darren Cole; a 5.5 minute video lecture on focal length

Bonus Learning Opportunities for Aperture and Focal Length:

1. Back to the Basics: Aperture/F-Stop part 2 by Valerie Hayken from VH Photography & Design, Photo-Talk; brief explanation of F-stops and the relationship to DOF
2. Photography 1 on 1: Aperture Values by Mark Wallace from AdoramaTV; an 8 minute YouTube video with thorough discussion on apertures, focal length, and aperture values
3. Understanding Camera Lenses from Cambridge in Colour; explanation of focal length with tables and drawings as well as photos
4. Lens Focal Length from Paragon Press; an article with comparative photos
5. The Use of Focal Length in Landscape Photography by Wim van Velzen from photoinf; an article with pictures