Bokeh Basics?

[mommy22]

I checked out the bokeh thread and realized I really don't know how to do that on purpose...I have a good camera but have only cracked the tip of the iceberg when it comes to stuff like that...

 

[Inst!nct]

Well, i apologize for the previous thread first of all, second, bokeh is pretty much the area of a photo that is out of focus.

http://everystockphoto.s3.amazonaws.com/bokeh_light_girl_375098_o.jpg

Differences in lens aberrations and aperture shape cause some lens designs to blur the image in a way that is pleasing to the eye, while others produce blurring that is unpleasant or distracting— "good" or "bad" bokeh, respectively Bokeh occurs for parts of the scene that lie outside the depth of field. Photographers sometimes deliberately use a shallow focus technique to create images with prominent out-of-focus regions.

so pretty much, you take a picture with a low aperture, focus on something in the foreground, the background will be out of focus, different bokeh, means different backgrounds per se,DScience i believe is his name, hes on this forum, good at that, might want to look up his flickr

File:Bokeh Example.jpg - Wikipedia, the free encyclopedia <== light bokeh

Different lens produce differnet bokeh, i believe that stepping back creates more bokeh, if you step back and zoom in, it might be the opposite, anywho, these are some examples

Wide aperture + long focal length = lots of bokeh

kind of like a 300mm + f / 2.5
Sun bathing on a Saturday morning on Flickr - Photo Sharing!
HBW on Flickr - Photo Sharing!
_ on Flickr - Photo Sharing! == DScience
prayer flag on Flickr - Photo Sharing! ,== DScience

 

[JSD]

I think that there is a miss use of the term "bokeh". Bokeh is a word derived from the Japanese word "boke", pronounced so that it sort of rhymes with "okay" and means out of focus (or it can also mean senile). What it has come to mean in photography is the nature of the out of focus area in a picture. The term "depth of field" refers to the zone of focus, the area in a picture that is in sharp focus, not the characteristics of the out of focus areas. Bokeh is determined mostly by the shape of the leaves of the diaphragm, and cannot be controlled by the photographer. Depth of field is controlled by the photographer when choosing an aperture, and by the focal length of the lens. Wide angle lenses have inherently more depth of field and telephotos, less. For a given lens a smaller aperture, for example f16 will have deep depth of field, and a wide aperture, such as f2.8, much less. Lenses used for landscape are usually short focal length, stopped down to a small aperture, say f16 or f22, hence the great depth of field between the flowers in the foreground and the snowcapped peaks in the distance. A shot of a bird, with limited depth of field where only the bird is sharp with the background blurry was likely taken with a telephoto lens at a wide aperture, say f2.8 or f4. Now the nature or characteristics of the blurry part of the bird shot, for example a point of light, although out of focus, might be nicely rounded or it may have angular edges, that is bokeh. I hope this helps to clarify the two terms.
JSD

 

[Pugs]

As JSD said, bokeh does refers to the quality of the blurred background (like perfectly rounded specular highlights), and Inst!nct gave a good overview of how to produce that blurred background.

 

[Dwig]

From the horse's mouth:
The Online Photographer: What Is Bokeh?

Mike Johnston, the author of the linked essay, coined the term "bokeh" and created its definition. He borrowed a Japanese word that is properly spelled in Latin characters as "boke" and added a trailing "h" so that English speakers would pronounce it more correctly.

Discussions of bokeh generally center more on the quality of the blur rather than the quantity. Quantity is merely a factor of depth-of-field (DOF). The quality of what blur is present is a factor of a number of optical and mechanical aspects of the lens and is out of the photographer's control other than his choice of lens.

The shape of the aperture is commonly mentioned as a major factor because its easy to see and describe, but its actually a minor factor in the quality of the bokeh except when the shaped is odd (e.g. catadioptic mirror lenses and their donut shaped aperture). Also, the iris blade shape only affects the aperture shape at apertures other than the maximum. The nature of the balance of optical corrections for spherical aberration and other corrections have the largest effect.