vignetting

Hi. I have the Sony Alpha 7 III and recently bought the MEIKE MK-35mm F/1.4 lens to use with it. However, the vignetting is incredibly heavy, to the point where the lens is pretty much unusable. Have I made a mistake? Is the lens perhaps incompatible with the camera? Thanks in advance to...

An auxiliary telephoto lens that attaches to the front of a lens can use a variety of groups/lenses. Some use 2 groups with 4 lenses, some use 3 groups with 5 etc. I'm unsure how it exactly works and i'm looking for somewhere to learn. Is there anyone that can explain how the optics work and...

Hello all I have just purchased the Luzid 100mm 6 stop filter. The supplier sent a Haida Gasket with it as I knew it wouldn't come with one. The gasket seems to creep quite a way onto the filter for my liking. It isn't tucked tightly to the edges. My question is . . . Will the Haida Gasket...