Just wanna know how true is it.
Vignetting effect (w/o using any filter) can happen on any DSLR body and any lenses. This is what I was told by a technician after I brought my camera for servicing.
I am not talking about the effects that was created on purpose, but just take a photo randomly and you will see it on your photo without any filter or lens hood attached, outdoor or indoor. All modes, all settings.