sigma 12-24mm with a lot of with dots in front elements

thebbm · Joined: 11 Dec 2013 Posts: 295 Location: France montpellier

hello
a friend of me have a sigma 12-24mm EX with a lot of with dots in front elements

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i don't see this dots in other web pictures nor on any of my lenses.
Any idea please ?

Lloydy · Expire: 2022-01-01

Possibly 'schneideritis' - apparently Schneider lenses are prone to this. The black paint around the outer rim of the lens elements fails and light / reflections enter the lens from the edges. I think the effect is more cosmetic, it looks bad, than it is bad for the actual image from the lens.

http://www.4photos.de/camera-diy/Schneideritis.html

Good article by Marcus Keinath.

thebbm · Joined: 11 Dec 2013 Posts: 295 Location: France montpellier

thank you Lloydy.
the lens is a little soft, i don't know if it is like that normaly or because of this 'schneideritis' ( for example at 19mm f5.6 it is softer that my sigma 19mm 2.8 dc on my sony nex 6 ). I hope the 'schneideritis' will not increase more, the owner told my that the lens fall in water.