Hornet - Thanks for the input. Looking over the K-5(ii) specs and viewing images online, I have no doubt it's a superb macro camera. My concern manifests in the ability to properly light subject matters in photomicroscopy, extreme macro (20x) if you will, is firing flashes on the rear (2nd) curtain shutter. There is another thread -
https://www.pentaxforums.com/forums/pentax-k-5/206820-pentax-k-5-k-5ii-k-5iis...-lenses-2.html - found after I posted, that notes the K-5 only fires on rear curtain if a PTTL flash and a Pentax lens with information contacts, i.e. K(af), is employed. Have you tried initiating rear curtain sync with your non PTTL setup and a non Pentax Lens?
Thanks again for your time and input.