Adobe Photoshop CS6, Руководство пользователя

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Correcting image distortion and noise
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Correction
Search Criteria
Lens Profiles
About lens distortion
Correct lens distortion and adjust perspective
Reduce image noise and JPEG artifacts
About lens distortion
Barrel distortion is a lens defect that causes straight lines to bow out toward the edges of the image. Pincushion distortion is the opposite effect,
where straight lines bend inward.
Examples of barrel distortion (left) and pincushion distortion (right)
Vignetting is a defect that darkens the corners of an image due to light falloff around the perimeter of the lens. Chromatic aberration appears as a
color fringe along the edges of objects, caused by the lens focusing on different colors of light in different planes.
Some lenses exhibit different defects at certain focal lengths, f - stops, and focus distances. With the Lens Correction filter, you can specify the
combination of settings used to make the image.
Correct lens distortion and adjust perspective
The Lens Correction filter fixes common lens flaws such as barrel and pincushion distortion, vignetting, and chromatic aberration. The filter works
only with 8
- and 16 - bit-per-channel images in RGB or Grayscale mode.
You can also use the filter to rotate an image or fix image perspective caused by vertical or horizontal camera tilt. The filter’s image grid makes
these adjustments easier and more accurate than using the Transform command.
Automatically correct image perspective and lens flaws
Using lens profiles, the default Auto Correction option quickly and accurately fixes distortion. For proper automatic correction, Photoshop requires
Exif metadata that identifies the camera and lens that created the image, and a matching lens profile on your system.
1. Choose Filter > Lens Correction.
2. Set the following options:
Select the problems you want to fix. If corrections undesirably extend or contract the image beyond original dimensions, select
Auto Scale Image.
The Edge menu specifies how to handle blank areas that result from pincushion, rotation, or perspective corrections. You can fill blank areas
with transparency or a color, or you can extend the edge pixels of the image.
Filters the Lens Profiles list. By default, profiles based on image sensor size appear first. To list RAW profiles first, click the
pop-up menu , and select Prefer RAW Profiles.
Select a matching profile. By default, Photoshop displays only profiles that match the camera and lens used to create the
image. (The camera model does not have to match perfectly.) Photoshop also automatically selects a matching sub-profile for the selected
lens based on focal length, f-stop and focus distance. To change the automatic selection, right-click the current lens profile, and select a
different sub-profile.
If you find no matching lens profile, click Search Online to acquire additional profiles created by the Photoshop community. To store online
profiles for future use, click the pop-up menu
, and choose Save Online Profile Locally.
To create your own profiles, download the free Adobe Lens Profile Creator from the Adobe website.