What is a Vignette? In photography, the lenses used are circular in shape while the image sensor or film plane is rectangular. In some circumstances, the corner of an image might receive less light. Corners are then darker than the center. Wide-angle lenses and lenses with very small aperture number show this usually more often.
A vignette is an imperfection?
This might be a desirable effect. Brighter parts of an image attract our eyes, having the corner darker might very well serve the picture. In other circumstances this needs to be fixed.
Some high-end cameras can compensate for this automatically on certain lenses made by the same manufacturer as the camera itself. Enabling this option is impacting only the small .jpg preview should you shoot in RAW. It will affect the entire image when you shoot in .jpg.
Some post-processing software will also recognize the lens used and might compensate automatically the fall-off in brightness in the corners should you enable this.
When this is a desirable effect, your post-processing software could be used to add and/or alter the characteristics of the vignette. In this case, we often refer to this as post-cropping vignette effect. The reason is should you crop the picture; the vignette will occur after cropping.
Properties of a vignette:
- Progressive versus hard edge;
- Round versus square;
- How big is the areas affected by the vignette;
- How much gain or loss of brightness.
When our eyes are exploring a picture, bright areas will them. Using a vignette is a way to prevent the eyes to wander outside the frame. Darker areas have a repulsive effect and eyes will wander back in the subject direction.
These images show before and after using a Vignette. It is important not to overdo it. When it is overdone, a Vignette will be distracting.
Should you want to know if your lens suffer from light fall-off in the corner, please visit SlrGear.com, they have a large database of lens data.