>>2574518>Also it needs a separate tool to remove it.All the generic M42-to-K adapters I've seen (the non-flanged ones that make it to infinity focus that is) have a tiny spring screwed in that locks them into the K-mount and allows you to unscrew the lens from the camera while leaving the adapter in. If you'd rather not mess around with that little tool to extract the adapter, just remove that little spring with an eyeglass screwdriver, and screw it onto the M42 lens. It'll stay on the lens, making it act like a regular K-mount lens. If you want to take it off the lens, put a K rear cap on it and turn, it'll engage the adapter and unscrew it.
Only downside is that a K-mount rear cap won't stay on the adapted lens very well.
