You have probably heard of lens diffraction and its effects of softening your images when the lens is set to a small aperture (large f-number). The image above illustrates diffraction effects (Click on the image to see an enlarged image in a new tab that more clearly demonstrates the diffraction effects. Modified from https://photographylife.com/wp-content/uploads/2016/04/The-Kiss-diffraction.jpg.)
Diffraction is present in all your photographs, and – if you aren’t careful – it can rob some sharpness from your favorite images. However, once you see its effects in practice, diffraction will become second nature.
If you want to find out more including:
- the causes of this effect
- how much it might affect your images depending on
- sensor size
- pixel density on the sensor
- and the interaction of aperture on depth of field and diffraction (wide aperture –> focus softening vs small aperture –> greater depth of field, but diffraction softening)
- minimising unwanted diffraction
… then read about it at https://photographylife.com/what-is-diffraction-in-photography.