This Canon EF 75-300mm f4-5.6 II would be something like a 2 or 3 out of 5 on our rating scale for optical condition. The camera used is a Sony A7R, and all shots were taken at f4, ISO200 in an attempt to regulate things a bit. Testing Varying Levels of Dirty Lensesįor the purposes of this unscientific experiment, I played with a few lenses with moderate to severe issues, shooting the same images for an easy comparison of the results. As the elements separate, however, the adhesive can cause the lens to reflect light differently, often leaving the lens with a rainbow pattern, similar to oil on water. Certain lens elements are glued to other elements with special adhesives that are invisible under normal circumstances. Separation is the result of adhesive breaking down. Eventually, even if the fungus is cleaned, it can cause irreparable damage to lens coatings.

Life begins to grow in the mixture, and the fungus will slowly grow across lens elements. What is lens fungus?įungus comes from a combination of dust and moisture trapped between the glass elements. Dust can be dirt, debris, chipped paint, or even hair from the environment that finds its way between the glass elements. Some lenses come close, but dust will sneak in no matter what. In order to focus, change apertures, etc. If you're unfamiliar with some of these terms read below, otherwise scroll down a bit more to let the tests begin! What is lens dust?ĭust can get into lenses in innumerable ways, and is the most common cause of a dirty lens. We’ll be talking about dust, haze, fungus, scratching, and separation today, in order to show just how much these things will affect the average photographer. So let’s set the record straight on dirty lenses and how different defects affect the quality of your photos.

Do cheap filters degrade image quality?.Every day we receive messages from people asking about how a dirty lens will affect image quality.

Dirt 5 performance vs image quality