Gaussian blur
As Blur ( English blur for blurring ) the deliberate change of a photo is called, in which the drawing ( the image) is reduced. The result of this art work is a blurring of the image or of specific parts of the image.
Features
The blur of a photo is a special kind of contrast change.
From a technical perspective, the contrast is reduced, because it created low contrast areas. This contrast reduction can be used very differentiated
- In certain areas of the image,
- For certain colors,
- In selected areas of brightness or
- A combination of the above
From a design perspective, this reduction in contrast is a stylization of local image areas and therefore acts as a differentiation from other image information. This stylization increases the perception of desired image detail and thus represents a special - design - contrast enhancement dar.
Demarcation
Blur is a conscious process generated the image change ( to reduce the drawing) and thus something other than the visibility of blur. Blur is only a measure for assessing the quality of images, contrast, blur a means of staged photography to change the image statement.
Blur is a change in the image statement by technical means. The aesthetic quality of this change is called bokeh. A Bokeh is strictly a concept of aesthetics, not a measure of the strength or differentiation of a blur.
Variants
There are very many ways to blur an image.
A special position is occupied by the automatic optimization methods of large photo labs. Here is the light well - between film and photo paper - a special transparent disc. This transparent plate can be partially blackened by electricity. This blackening always depicts a the blurred image of the photo. Using this method, all manufactured in large laboratories photos to be optimized since the early 1990s.
Soft Focus Lenses
The lenses used for softening are called Blur. In some eras of photography, as in the time at the beginning of the 20th century this was considered as a conscious departure from the naturalistic representation meticulously accurate and sharp images.
Example of Soft Focus lenses are:
- Rodenstock Imagon lenses and lens heads with interchangeable Siebblenden ( different focal lengths for various image formats )
- Sima 2/100mm lens with interchangeable Siebblenden
- Minolta Varisoft - lens with a continuously variable soft focus ( Minolta 2,8 / 85mm Varisoft )
- Minolta soft-focus lens with a continuously variable soft focus ( Minolta AF 2,8 / 100mm Soft Focus)
- Canon Soft Focus Lens with two blur levels (switchable) ( Canon EF 135mm 1:2.8 Soft Focus)
- Seibold cal Dreamagon lens with gap segmental orifice ( 4/90mm )
Gaussian Blur
A typical software solution for softening of digital photos is the Gaussian Blur using the Gaussian filter. The name is based on the " Gaussian " normal distribution, which was developed by Johann Carl Friedrich Gauss.
- Comparison between blur, sharpness and blur
Sharp Exit Photo
Sharp image that has been modified with " Gaussian Blur"
Creative mix of sharp and weichgezeichnetem Photo
Application
A soft-focus lens used in traditional photography or a Blur filter creates a sharp image, a portion of which is superimposed blur. This affects the image, which is still perceived as sharp as romantic and dreamlike. Such effects are popular for example in portrait photography since pored skin looks much smoother.
Furthermore, there is blur filters that capture only areal objects but leave image edges unchanged, so-called despeckling or median filter.
Digital Blur is a low-pass filtering. Small structures ( the "Subscription " ) are filtered out with it. Therefore softening can also be used, if grids are to be removed.
Blur is often used for portrait photography, in particular in the digital post- eyes are left free in order to blur, as these should be always in focus when shooting portraits. Also suitable Blur in nude photography used. In contrast, the blur is usually not used in landscape photography.