UNIVERSITY OF THE PHILIPPINESDiliman, Quezon City

MEDIA TECHNOLOGY – PHOTOGRAPHY

Depth of FieldFocal Length

Aperture

By:

JENNIFER J. LALUNA

GENERAL TERM

Depth of field (DOF) refers to the range of distance that appears

acceptably sharp. It varies depending on camera type,

aperture and focusing distance.

Depth of Field

DEEP

is when

the included

range

is a couple

of yards

to infinity.

Depth of Field

SHALLOW

is when

the included

focus

range is

very narrow,

a few inches

to several

feet.

In both cases DOF is measured in front of the focus

point and behind the focus point

USING SHALLOW DEPTHS OF FIELD FOR

PORTRAITS

Depth of Field- Shallow Depths

Using a wide aperture is a classic portrait technique that’s

guaranteed to give your image maximum impact. The reason it

works so well is because it can be used to focus the viewer’s

attention onto your subject.

Depth of Field- Shallow Depths

For a close up portrait shot position your subject away from the

background and zoom in to fill the frame. This is more practical

than reducing depth of field by trying to get very close to your

subject

Depth of Field- Shallow Depths

Depth of Field- Shallow Depths

For Full control over the

depth of field, set the

exposure mode to Aperture

Priority and let the camera

choose the shutter speed.

Dial in a wide aperture

setting (small f number).

Note that prime lenses tend

to have wider maximum

aperture than zoom lenses.

prime lenseszoom lenses

Depth of Field- Shallow Depth

When you’re using a wide

aperture setting. Focusing is

critical because of the

shallow depth of field. The

best method is to pick the

autofocus point yourself.

Zooming in and setting a wide aperture has

reduced the depth of field, with the nearest

and furthest elements thrown out of focus.

The light catching one flower draws further

attention to other element .

OTHER RESULTS USING DEPTH OF FIELD

Depth of Field- Shallow and Deep Depths

SHALLOW DEPTHDEEP DEPTH

Another example of a

shallow depth of field

effect for close up as the

distracting background is

"thrown" out of focus to

draw the viewer's

attention to the main

subject.

Depth of Field- Shallow Depths

MAXIMUM DEPTH

OF FIELD

it shows the details

of the scene

if we want to show

the entire scope of

the scene from

NEAR to FAR in

sharp focus.

A smaller aperture is

used along with a

28mm wideangle

lens to achieve the

objective.

Maximum Depth of Field

Depth of Field

FOCAL LENGTHFOCAL LENGTH- Distance from the lens to the film.

In other words, focal length equals image

distance for a far subject. To focus on

something closer than infinity, the lens is

moved farther away from the film. This is

why most lenses get longer when you

turn the focusing ring.

The distances follow this formula:

This means a 400mm lens should be 400mm long. If you get out your ruler

and measure it, you will find it is less than 400mm. That is because a

camera lens really has many individual glass lenses inside, and this makes

it behave as if it is longer than it really is. This is called "telephoto.“

F STOPis the focal length divided by the diameter of the lens.

For example:

F-stop is typically written as F/4, meaning "focal-length over 4" or

"focal-length divided by four".

FOCAL LENGTH

Where do those numbers come from?Lenses are marked with a series of f-stops, each one lets in half as

much light as the previous one. The light-gathering ability of a lens is

determined by its area, and f-stops are determined by diameter. Area is

related to diameter squared. The progression of f-stops, 1 - 1.4 - 2 - 2.8 -

4 - 5.6 - 8 - 11 - 16 - 22 - 32, are powers of the square root of 2.

FOCAL LENGTH

Lens Focal Length Chart

These eight photos were taken from the same place with different lenses.

The subject is Longs Peak from Upper Beaver Meadows in Rocky Mountain

National Park.

FOCAL LENGTH

Focal length

Conclusion

Manipulation of depth of field is a good way to modify

the characteristics of your photo

Manipulating the aperture is the ideal way to do this

because it has little or no effect on composition.

You simply need to change the shutter speed (or

change the light sensitivity – ISO) to compensate for

the changes in the exposure from the adjustments to

the f-number.

Changes in distance and focal length also affect DOF,

but these changes have trade-offs in terms of

composition.

Therefore, changes to aperture are the best way to

manipulate DOF without affecting a photo’s

composition.

REFERENCES

http://download.fromdoctopdf.com/index.jhtml?partner=Y6xdm269&gclid=CKK777uEr8

cCFRcMjgoddtQAPQ

http://www.exposureguide.com/focusing-basics.htm

http://www.digitalcameraworld.com/2014/05/09/a-laymans-guide-to-depth-of-field-how-

to-check-and-affect-sharpness-like-a-pro/