Dust Perception Factor – Dust Analysis

Dust Perception Factor (DPF) is an experimental metric designed to indicate how likely a dust spot is to be notices in a final image

Key:

• Red diamond: indication of how likely a spot is to be seen in a final image
• Blue line – indicates the approximate threshold of where spots will be seen in images.

Basic Interpretation

Dust Perception Factor (DPF) is an experimental metric designed to indicate how likely a dust spot is to be notices in a final image. The DPF is a calculated from the frequency of occurrence of the dust spots, their size and their opacity. A higher value suggests that the dust spot is more likely to be noticed in an image.

The value of 10 is approximately the point where a dust spot would be noticed against a plain background – this is indicated on the chart with a blue horizontal line.

There are many factors which can affect how noticeable sensor marks are, not least of which is image content which cannot be taken into account here. As such, DPF is a guidance value which may be of some use in deciding whether to clean your sensor but may produce incorrect values under some circumstances.