The next part of our Know Your Camera assignment is about Vignettes.
Vignette is defined as
In digital photography a vignette is also referred to to as ‘light fall-off’ where the edges of the photograph are darker than the centre. It can be caused by the lens, increased by filters or lens hoods or can be added as part of the post production process.
Vignetting can occur in a number of ways. One of the main ways though is caused by the light being obscured by the barrel of the lens so that light rays that enter the lens at an acute angle ‘falls off’ at the edges. It can also affect the shape of the lens bokeh to make it look more like cat’s eyes than pretty circles.
Another thing to remember is that light coming in at an angle at the edges of the lens travels further than light heading straight into the lens. This means that light is weaker at the edges, also causing vignetting.
Another cause is that light is hitting a flat sensor at different angles. In the centre, the light is hitting the sensor head on but around the edges it meets the sensor at a slight angle also causing vignetting.
I understand that some cameras have built in software that can correct vignetting in jpegs but this information is not stored in RAW files and is ignored by Lightroom and Aperture. Both Lightroom and Aperture have features that can help to correct or enhance vignetting.
I wanted to check how much vignetting my camera and lens has. So I took three photographs, all of the same thing at different apertures in order to compare the vignetting.
Fortunately even at the widest aperture the vignetting is very slight and almost imperceptible.