In my childhood home, a Dust Donut was what we called and cake or cookie that had gotten lost down the back of the sofa or under an armchair, only to be rediscovered weeks or months later, covered in (you guessed it) a layer of dust and lint.
However, the Dust Donut we’re talking about today is a simple aftermarket weather seal for your Canon SLR lenses.
Dust and moisture can sneak inside your camera and lens at the point where the two connect. High-end lenses are weather-sealed, but most of them are left to fend for themselves. The Dust Donut is a $35 rubber ring made to perfectly fit the EF mount lenses and keep the crap out.
Moisture isn’t often a problem unless you shoot in the rain and the wet, but dust is a bigger issue with digital than it ever was with film. Film gives you a brand-new “sensor” every time you wind it to the next frame. Digital lets the dust build up on the sensor, so it’s important to keep it out.
The Donut is a Kickstarter candidate, but the campaign is little more than a way to sell the seals, which are already being made in some far-off factory somewhere.