DSLR Photography Forum

I have 2 pentagon lenses from my old 35mm camera, I have bought a 42mm to canon adapter ring so that I can use these on my 650D.
Unfortunately it is very difficult to focus, I have seen chipped adapter rings on ebay, has anyone tried these? do they work?
Is there any possibility of them causing damage to my camera?

The chipped adapters allow you to have focus confirmation. You still turn the focusing ring on the lens, but you get a beep to confirm the maximum sharpness.