tysout:
I'm absolutely no expert on this subject, but it appears that some subs release endorphins and go into something called sub-space.This allows them to take an enormous amount of punishment and not actually feel it at the time.They do apparently suffer quite badly the next day.However, you're totally right CK, why use them when making a spanking video?...it's pointless!
Well, I've experienced that on occasion--swats that had me squirming and squealing a minute or two earlier start to feel physically pleasant (they're always gratifying psychologically), almost like a brisk massage. At that point, my sweet spouse ideally will switch to a more severe implement to bring back the squirms and squeals, but eventually I'll tend to reach 'subspace' via that spanking toy as well.
My wife isn't such a strict spankmistress that my buttocks ever end up seriously bruised or blistered (regardless of my fondness for the term "blistering" in my writing), but they can end up feeling quite sore and sizzling once the endorphins have ceased flowing.
However, who wants to watch a spankee experiencing 'subspace' in a video or DVD? Once he/she reaches that point, assuming that he/she does, I'd venture that the spanker should switch to a more hurtful instrument of correction and continue on, bringing a return to yelping, wriggling and howling, even eventually bawling.
The fantasy which I primarily embrace in spanking-oriented materials, whether videos/DVDs, artwork or literature, is that the discipline recipient is truly being punished (at least at the surface level of his/her awareness), in which case he/she won't ever reach 'subspace,' but rather will demonstrate increasingly desperate reactions (possibly including all-out crying) to his/her chastisement, until either the spanking finally concludes (my general preference) or his/her resistance is broken, leaving him/her softly sobbing with each continued impact.
Experiencing 'subspace' personally is a terrific situation, but to me it's hardly exciting to view it happening to someone else...

--C.K.