Most new lenses, now come with 9 rounded blades, which render round bokeh (Nikon 105mm f/2.8G VR):
Many older lenses such as Nikon 50mm f/1.4D have 7 straight blades in their diaphragms, which results in heptagon-shaped bokeh like this: The shape of the reflected light in out of focus areas depends on the lens diaphragm. Open up the larger version of the above image and see for yourself – the quality of the blur is not pleasant to the eye, with sharp edges of the circles and double lines.
#Bokeh video background iso#
How about bad or ugly bokeh? Although a lot of people argue that there is no such thing as a bad bokeh, I still call whatever distracts my eyes “bad”: NIKON D80 26mm, ISO 100, 1/60, f/4.0 That’s exactly what you would call good bokeh! The out-of-focus areas look creamy and the circles are round and soft with beautiful transitions between the blurry areas. Pay attention to the smooth background behind the child’s face. Here is an example of beautiful bokeh rendered by the Nikon 85mm f/1.4D lens: NIKON D700 85mm, ISO 250, 1/200, f/2.8 So, what is a good or beautiful bokeh? A good bokeh pleases our eyes and our perception of the image and therefore, the background blur should appear soft and “creamy”, with smooth round circles of light and no hard edges. Again, I am not just talking about the background blur all lenses are capable of producing out of focus blur, but not all lenses are capable of rendering beautiful bokeh. For example, the Nikon 85mm f/1.4D lens produces exceptionally good-looking bokeh, while the Nikon 18-135mm f/3.5-5.6G DX lens produces poor bokeh at the same focal length and aperture – all due to differences in optical designs of both lenses. Generally, portrait and telephoto lenses with large maximum apertures yield more pleasant-looking bokeh than cheaper consumer zoom lenses. Different lenses render bokeh differently due to unique optical designs. Remember, bokeh is rendered by the lens, not the camera. While some photographers argue that bokeh is just about the quality of the circular light reflections, many others, including myself, believe that bokeh is about the quality of the entire out-of-focus area, not just reflections and highlights… Good and Bad Bokeh In this case, the soft “feel” of those circular areas is what photographers would call “good bokeh”. See those round circles of different colors on the left side of the image? Those are light reflections and they are circular because that’s how the lens rendered them. The small or “shallow” depth of field is the result of standing relatively close to the subject, while using a large aperture. The house sparrow is in focus and sharp (which means that it is inside the depth of field), while the background is out of focus (which means that the background is outside the depth of field). Confused yet? Take a look at the following image: NIKON D80 102mm, ISO 100, 1/100, f/2.8 The quality and feel of the background/foreground blur and reflected points of light, however, is what photographers call Bokeh. The blur that you are so used to seeing in photography that separates a subject from the background is the result of shallow “ depth of field” and is generally simply called “background blur”. Basically, bokeh is the quality of out-of-focus or “blurry” parts of the image rendered by a camera lens – it is NOT the blur itself or the amount of blur in the foreground or the background of a subject.