Question about flange distance of lens adapters and acual lens - camcorders

[demoboy]

Not sure if this is actually ''custom'' or not, and this specifically relates camcorders with zoom lenses. As I see it, a camcorder lens is already calibrated for optimal performance for the sensor. However, when you buy macro lens filters with industry screw on threads, are the adapter manufacturers calibrating their glass to the intended camcorder glass? What I mean is, with the new age of cell phones and Zeiss add on lenses. The lens glass from the cell phones require a protocol distance to the adapter glass? Does it matter if the glass of the adapter literally touches the main lens? I'd imagine with no flange of adapter glass touching main glass there's no focusing issue?

 

[Samuel H]

That's a low-budget option and I think they just go with the flow, even if it's not optimal. Basically, it's something you do to the lens, that it wasn't designed for. It works... kind of.