Blur

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Soft focus photo
Soft focus by reducing the contrast without losing sharpness in a portrait

As blur the conscious change is a photos referred to in the drawing or the contrast (the image) is reduced. The result of this composition is a blurring of the image or certain parts of the image.

features

Softening a photo is a special type of contrast change .

From a technical point of view, the contrast is reduced because there are low-contrast areas. This reduction in contrast can be used in a very differentiated manner

  • in certain image areas,
  • for certain colors,
  • in selected brightness areas or
  • a combination of the above

From a design point of view, this reduction in contrast represents a stylization of local image areas and therefore acts as a differentiation from other image information. This stylization increases the perception of desired image details and therefore represents a special - creative - increase in contrast.

In the left picture the hair contains more drawing, in the right picture the contrast within the hair area has been changed.

Demarcation

Soft focus to simulate shallow depth of field

Blurring is a deliberately created process of changing the image (to reduce the drawing) and thus something different from the visibility of blurring . Blurring is only a measure for assessing the quality of images , while blurring is a means of staged photography to change the image's message.

Blurring is a change in the image message with the help of technical means. The aesthetic quality of this change is known as bokeh . A bokeh is only an aesthetic term, not a measure of the strength or differentiation of a soft focus.

variants

There are many ways to blur an image.

  1. The soft focus before the image is saved. The methods used are independent of the type of image storage (film, file). The following can be mentioned as examples:
    1. The influence of light (example: diffuse light )
    2. The use of effect filters (example: effect filters ).
    3. The conscious use of lenses ( defocusing ).
    4. "Home remedies" like petroleum jelly (or skin oil from the nasal fold) on a filter in front of the lens; nylon stockings stretched over the lens (different effects due to black, white or brown)
  2. The soft focus after saving the image.
    1. The blurring of an analog image can essentially be done through the correct use of effect filters and lenses (in the enlarger ).
    2. Numerous software solutions can be used to soften digital images .

The automatic optimization process of large photo laboratories occupies a special position. There is a special transparent pane in the light shaft between the film and the photo paper. This transparent pane can be partially blackened by electricity. This blackening always creates a soft image of the photo. With the help of this process, all photos produced in large laboratories have been optimized since the beginning of the 1990s .

Soft focus lenses

Landscape shot with a soft focus lens

The lenses used for soft focus are called soft focus . In some epochs of photography, such as at the beginning of the 20th century, this was seen as a conscious departure from the naturalistic representation of meticulously precise and sharp images. Various special lenses for this purpose are offered by the industry today.

Examples of soft focus lenses are:

  • Rodenstock Imagon lenses and lens heads with interchangeable screen apertures (different focal lengths for different image formats)
  • Sima 2 / 100mm lens with interchangeable screen apertures
  • Minolta Varisoft lens with continuously variable soft focus (Minolta 2.8 / 85mm Varisoft)
  • Minolta Soft Focus lens with continuously variable soft focus (Minolta AF 2.8 / 100mm Soft Focus)
  • Canon soft focus lens with two levels of soft focus (can be switched off) (Canon EF 135mm 1: 2.8 soft focus)
  • Seibold's Dreamagon lens with slit segment diaphragm (4 / 90mm)

Gaussian soft focus

A typical software solution for the soft focus of digital photos is the Gaussian soft focus with the help of 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 soft focus

  • Blurred initial photo

  • Sharp initial photo

  • Sharp image that has been modified with "Gaussian Blur"

  • Creative mix of sharp and blurred photos

application

Reduction of an annoying print screen through blurring

A soft focus lens or a soft focus filter used in classic photography creates a sharp image on which a portion of blurring is superimposed. As a result, the image, which is still perceived as sharp, appears romantic and dreamlike. Such effects are popular in portrait photography , for example , as large-pored skin appears much smoother.

There are also soft focus filters that only capture two-dimensional objects, but leave the image edges unchanged, so-called despeckle or median filters .

Digital soft focus is a low-pass filter . Small structures (the "drawing") are filtered out. This is why blurring can also be used when halftoning is to be removed.

Softening is often used in portrait photography , whereby the eyes are left out for the purpose of softening, especially during digital post-processing, as these should always be in focus in portraits. Soft focus is also used in nude photography . In landscape photography , on the other hand, blurring is usually not used.

Web links

Individual evidence

  1. ↑ Example: Removal of engraving lines ( memento of March 10, 2010 in the Internet Archive ) for the comparison of larger structures in a wood engraving (1876, Henry Holiday) and in an etching (1566–1568, Markus Gheeraerts the Elder).