Sigma 30mm f1.4 strange circle appearing

Started Jan 7, 2019 | Discussions thread
ForumParentFirstPrevious
Flat view
Skiny New Member • Posts: 14
Sigma 30mm f1.4 strange circle appearing

Hi,

Does anyone know what might be causing this strange affect to appear on my photos.  Lens is a Sigma 30mm 1.4 and I have tried it on a couple of cameras with same results.  It's more obvious on low F stops.

It's almost like the opposite of a vignette, where the outer edges are lighter than the inner circle.

Glass is clean on both ends, and internally from what I can tell.

ForumParentFirstPrevious
Flat view
ForumParentFirstPrevious
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow