Let's look—briefly—at the other panels on the right side of the Develop Module.
There are three panels.
Lenses may create the three errors below.
Lenses, especially wide-angle lenses, create distortion.
The distortion is evident when photographing architecture.
Let's say you're photographing in Rockefeller Center.
You point your camera up and photograph the buildings.
The buildings appear to get smaller.
Their lines converge.
This is perspective distortion.
Distortion may appear in a landscape as a curved horizon line.
Horizons are not curved unless you're high enough to see the curvature of the earth!
Use a focal length of 70mm to 100mm with most digital SLR cameras.
The perspective of the subject's face will be normal looking.
Wide-angle focal lengths enlarge the person's face, especially his or her nose.
Long telephoto focal lengths larger than 100mm flatten the subject's face.
Lenses may produce chromatic aberration.
This occurs when the colors in a scene are not uniformly focused on the sensor.
For example, let's say:
• The green and blue light are focused on the sensor.
• The red light is not focused on the sensor.
The red light's focus point is a little in front of the sensor.
Therefore, a red fringe may appear along the edges of the subject in the photograph.
You don't need to read the following description of chromatic aberration.
The described above is called longitudinal chromatic aberration or axial chromatic aberration.
The fringing can appear anywhere on the photograph.
Longitudinal chromatic aberration can be reduced my using smaller lens openings, such as f/16.
The increase in depth-of-field at smaller lens openings mitigates the focus issue.
There's a second type of chromatic aberration called transverse or lateral.
Think of the first type as being certain colors of light rays are not focusing on the sensor.
Think of the second type of chromatic aberration as being rays of light hitting the sensor at the wrong position.
Let's say you're photographing a cyan colored sculpture.
Cyan light is made up of blue and green.
Let's say there's a Point X on the sculpture.
There are blue and green rays of light coming from Point X.
The rays of each of the two colors should strike the sensor at the same position.
If one of the two colors doesn't, then you'll see fringing.
Transverse chromatic aberration is only seen near the edges of a photograph.
Chromatic aberration may also be cause by:
• Lens flare.
• Interactions between the light and the lenses on the sensor.
• Differing dynamic ranges of photosites.
Lenses, especially wide-angle lenses, may not project an image on the sensor with uniform brightness.
The corners may be darkened, vignetted.
The Lens Corrections panel has four sections.
Select Enable Profile Corrections.
Then, go to the second section, Profile, and select the lens that was used.
If chromatic aberration is present, select Remove Chromatic Aberration.
Let's say you're straightening a crooked horizon.
When you do so, the photograph is rotated.
The corners of the photograph are now sticking outside the original photograph.
When Constrain Crop is selected, Lightroom will maintain the original image size.
There are four tools.
When using Level, the horizon line must be obvious.
Click Auto to:
• Correct horizontal perspective distortions.
Level only straightens.
Vertical corrects vertical perspective distortions only.
Click Full to:
• Correct horizontal perspective distortions.
• Correct vertical perspective distortions.
You can select the specific lens that was used, enabling Lightroom to make better corrections.
If your lens isn't listed
Fringing is when an anomalous color is present along the edges of objects in the scene.
For example, fringing may be present on leafless tree branches against the sky.
You can make manual adjustments in this section.
You can add two effects with this panel.
Vignetting darkens or lightens the edges of a photograph.
Post-crop vignetting maintains the effect even if you crop the photograph later.
There are three styles.
Highlight Priority is similar to the Recovery slider in the basic panel.
Color Priority reduces color shifts in the darkened areas of the photograph.
Paint Overlay blends the photograph with black or white.
You can choose the tone of the vignette.
The Midpoint slider adjusts the size of the vignetted area.
You can shift the shape of the vignette from circular to oval to rectangular.
Feathering is the degree to which the vignette fades along its inner perimeter.
You can brighten and darken highlights when using a dark vignette with the Highlight Priority or Color Priority styles.
Grain simulates the grain of high-ISO films such as Tri-x.
The three sliders, Amount, Size, and Roughness, are self-explanatory.
Your camera develops the raw information from the sensor into a JPEG.
You can select several developing styles, such as:
When you open a raw file in Lightroom, you can apply the above settings to the file using this panel.