Testing the Impact of Scratches, Dust and Fingerprints on Image Quality

Jordan Drake and Chris Niccolls over at DPReview TV recently published a follow-up to their lens cleaning video, where they tested something that we’ve all wondered: how much do scratches, dust, water droplets, and fingerprints on your lens really impact image quality?

In the video, Drake and Niccolls cover the gamut of schmutz and damage that you could do to your front element. From fingerprints, to mist and water droplets, to shallow scratches, to deep gouges (ouch…), each potential bit of damage or dirt was tested both wide open and stopped down, and then compared to a control lens that’s clean.

In the end, Niccolls explains how and who some people can get away with even a lot of damage… if they shoot wide open:

What we’re seeing is an absolute relationship between how bad these obstructions are gonna show up, and how much depth of field you have. When … using telephoto lenses or … shooting wide open, a lot of these problems are minimized or disappear almost entirely. It’s when we increase the depth of field… that these obstructions start to show up as damage and shadows that we can easily see.

Check out the full video up top to see the tests and sample images for yourself, and head over to the DPReview website if you want to pixel peep those same samples. For our part, we were surprised to see how some of the worst overall image quality drop came from the easiest thing to clean: fingerprints and water. So keep those front (and rear) elements clean, and maybe don’t sweat the small scratches and dust as much… they have less of an impact than you might think.