Diffraction is a topic that pops up regularly in photography and filmmaking. “Oh, you don’t want to stop your lens down all the way, you’ll get diffraction!”. But what is diffraction, how does it affect your shot, can anything be done about it and should you really even care?
Macro photography expert Don Komarechka has just put out a great video for DPReview TV going into quite some depth to explain the cause of diffraction – in a very easy-to-digest way with lots of practical demonstrations – and why it makes your images softer the more you stop down your aperture.
Essentially, diffraction is caused by the wave-like nature of light. And like other things that form waves (like water), when light passes through an opening that’s way too small, it bends and starts going off-course. The result of all this is that instead of a specific point of light in front of the lens hitting just one pixel on the sensor, it’s hitting a whole bunch of them. And that’s happening to all of the rest of the sensor’s pixels throughout the image, too. This means that each pixel on the sensor is actually seeing what its basically light pollution from the surrounding pixels, which results in softness in the final image.
So, yes, you should absolutely care about diffraction, especially if you’re trying to capture the sharpest and most detailed images you can. But what can you do about it? Well, just don’t stop down your aperture too much. Test your lenses to see where they start to break down in quality. That way, when you’re shooting something for real, you know what your limits are and the level of softness you’re willing to accept.
Is diffraction an issue you run into regularly? Or are you an f/1.4 bokeh-queen?
[via DPReview TV]