Minolta Lens Question

[HP&MP]

I was just wondering if this is normal behavior for this lens (Minolta 28 F2.8 MD). In the picture you can see that there is a circle in the middle of the image that appears when I stop the lens down (here at F22). However, when I focus to infinity the circle disappears. I am using the lens with a gh2 and fotodiox lens adapter, so maybe the adapter is causing this. Sorry if this is a dumb question, but any explanations are greatly appreciated.

 

[GrahamH]

I used a Minolta Celtic 28mm f2.8 with my GH2 and don't recall any such problem (I've since sold that lens).

With various legacy lenses, however, I've had occasional issues with internal reflections from the rear lens element, lens mount, or adapter. Does the spot vary in intensity when there are strong light sources in frame, or nearly in frame? If so, try darkening any shiny internal surfaces with a black marker pen.

 

[HP&MP]

Thank you for the reply. I thought it might be some sort of reflection issue and the odd thing is that this dot appears in the same spot in a couple of similar pics from a different angle. I appreciate the suggestions and will definitely give them a try.