Originally posted by DonV " release the offending adaptor from behind"
A pre-installation exam would have been helpful and perhaps avoided the problem; but either your adapter was broken/modified or you didn't notice how to release it from the front;
Some of these are designed to lock in place- others are not; but they are not designed to require disassembly to remove.
The adaptor was certainly faulty in one respect or another.
I've had a Pentax original since my *
ist film camera, so am well aware of the use and how to release it, I even still have the original instructions which recommend the use of "a ballpoint pen or the like" to release the spring and rotate the adaptor, (I usually manage quite well with a fingernail).
However, the faulty unit jammed onto the lens thread, possibly due to an over-length screw or a deformed thread, and the force required to overcome this jamming caused the spring to distort, preventing release from the front!
Needless to say, I've not used an aftermarket adaptor since without removing the spring first
---------- Post added 09-23-21 at 03:17 PM ----------
Originally posted by vonBaloney Again, if you buy one of the cheaper third-party ones and don't take the spring out immediately before you use it, it doesn't matter one bit how it was "designed", YOU WILL HAVE A LENS GET STUCK. That will happen, guaranteed. (You will have no such problems with a genuine Pentax one though.)
This advice is all very well in this day and age with the benefit of hindsight, but "back in the day" I certainly was unaware of any potential problems, simply acknowledging that the after-market items needed the supplied release tool to remove the adaptor, assuming because that option was cheaper than producing the adaptor to the critical clearances required for ease of removal whilst retaining a shake-free fit.