Is this a Newton Ring in my EF-M 14-45mm

[duffmasterj]

This concentric ring appears at every focal length in the same spot, in the top left corner, at aperatures 6.0 and smaller, magnified with more zoom toward 45mm.  With or without hood or filter or angle of the sun.  I bought the lens used...is this a defect?

[deebatman316 · Accepted solution]

That looks like dust on the image sensor.

[duffmasterj]

I agree those spots are likely dust, but perhaps on or in the lens.  This doesn't occur with a prime 55mm lens...But more specifically, what is that concentric rings in the top left corner which again, appears at F6 and smaller?   The seller has issues a refund for the camera, but I'm very curious what that is.

[p4pictures · Accepted solution]

The visibility of dust spots depends on the aperture being used. I used to own an EOS 5D Mark III and shot mostly with lenses wide open or no more than 2-stops from wide open and saw no dust spots in my images. I then shot some macro work at f/16 and the spots were everywhere on the sensor. 

Dust like you show might be where someone has tried to clean the sensor and in the process left a bubble of cleaning fluid on there.

[normadel · Accepted solution]

Dust in or on the lens does not produce a clear image of itself at the sensor.

[ebiggs1 · Accepted solution]

Although that looks like Newton’s Ring almost everything you see in photography that looks like a Newton’s Ring is not a Newton’s Ring. And yours isn’t one either. I’m going with dust.