Help needed - Foggy element on a Sigma 18-35mm - with pics -

[Smoli4]

here is the foggy element, If its the cement then theres nothing to do, but if its something else than i should be able to clean it

BUT this freaking group is glued together and held in a plastic solid and sealed FRAME
i need some idea of what to do in this case i really want to repair this issue since its a full frame lens, and the obviously very wide.

[SXR_Mark]

I've seen this sort of fogging before and one hopes it is just dirt or condensation. But it always turns out to be either cement failure or coating deterioration. In either case, it cannot be fixed. Since the group is glued together in the frame, it is not really practical to attempt repair even if it were just dirt. Probably the only thing you can do is contact Sigma and see if they still have a replacement group as a spare part. Or use the lens as is.

Mark

[Smoli4]

ive updated this thread in the Repair section. i managed to detach the foggy element and it was indeed condensation that i have cleaned.
but all in all the buttom line is that the lens is usable again, with AF maintained

[SXR_Mark]

Excellent! A happy ending And a good job on taking an AF zoom apart and getting it back together again.