When taking photos with the camera or smartphone, the background should be sharp and blurred at times. But what is the technical term for the sharpness in the depth of the picture - depth of field or depth of field? Every time I write an article that uses that word, I have to see if it's called depth of field, or skewing, or goat's sharpness, or whatever. The first is of course correct. The actually incorrect term "depth of field" has also established itself in colloquial language. There is no difference in content.
However, if you want to get the spelling right, you can simply remember that the order in the alphabet must be observed: SSHARPENTIEFE. So first an S and then a T. That way I can certainly memorize it.
Chapter in this post:
What exactly is depth of field?
The meaning of the individual words should be clear: “Sharpness” stands for the clear depiction of an object or motif, and “Depth” refers to the spatial expansion of the photograph - the Z-axis in the photo, so to speak. The depth of field describes whether and how sharp or unsharp certain depths are. This should be known from macro, portrait, tilt-shift effect and bokeh photography, because they play with blurring.
The following applies with regard to the sharpness of the background:
- Shallow depth of field = Blurred background
- High depth of field = sharp background
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What is depth of field used for?
A high depth of field - or colloquially depth of field - is used, for example, in a landscape shot, a panorama or any other photograph in which the entire image content is important. A blur in the image depth is used as a stylistic device when an object in the foreground is to be emphasized and/or the image background would be too distracting in full focus.
Set depth of field with aperture, distance and focal length
It is important to know that with digital cameras, including DSLR cameras, the sensor size has an effect on the game with sharpness in depth. The larger the image sensor in the camera, the more leeway there is. No less important, however, are the proximity or distance to the photographed object as well as the aperture settings (exposure partly affects the sharpness) and the choice of focal length. The following comments:
- Depth of Field by Aperture: The larger the aperture value, the less open the aperture, the sharper the background. Or: The smaller the aperture value, the more open the aperture, the shallower the depth of field.
- Distance to the object: As you may know from macro photography, the depth of field is smaller when you move closer to the photographed object. If you want the background to be sharp, move away from it.
- Focal length and depth of field: A short focal length (wide-angle lens) gives greater sharpness in depth than a long focal length (telephoto lens). The effects can each be weakened or strengthened by the above factors.
Geometry, physics and examples on the topic
If you want to know exactly, then take a look at Wikipedia article on the subject past. There the depth of field is explained very precisely and wonderfully inscrutable for laypeople. So if you have fun with the geometry, the physics and the complex formulas behind the depth of field (not depth of field), you can really live it out and see many numbers and tables to internalize. Fortunately, there are also pictures and animations as examples for different techniques and sharpness values;)
Jens has been running the blog since 2012. He acts as Sir Apfelot for his readers and helps them with technical problems. In his spare time he rides electric unicycles, takes photos (preferably with the iPhone, of course), climbs around in the Hessian mountains or hikes with the family. His articles deal with Apple products, news from the world of drones or solutions to current bugs.