Terrible Novoflex video of "bellows draw" focus stacking

Fair warning: this video is from Novoflex, which kinda' automatically implies

• Minimal information and overaggressive sales-talk.
• Insane prices: this is a $3,600 replacement for a $400 StackShot
• Pure BS. Like the dreadful misexplanation of how bellows draw focusing affects stacking range.

You have been warned. I've cued it up to the relevant part for you.

https://youtu.be/RIrSCt0dIjE?t=280

It's simply the first time I recall ever seeing anyone other than me talking about focus stacking using "bellows draw" or movement of the camera away from the subject without moving the lens. Those who know me know that I often recommend using this technique for focus stacking, because it eliminates all the zarking halos, background tear, etc.

Bellows draw involves setting up a bellows, getting into range by shifting the lens on the front "standard" of the bellows or "racking" the entire bellows, then doing the stack by shifting the rear standard. By keeping the lens at the same place in relation to the subject throughout the entire stack, there's no perspective shift, and therefore, no halos or background tearups.

I do it manually with a Nikon PB-4 bellows or automatically with a home-made bellows.

The PB-4 (like the newer PB-6) has the three major movements: front standard, rear standard, and rack (move the whole bellows and camera, just like a focus rail). This isn't as hard as you think, because the rear standard focus motion is minimized in proportion to the magnification: i.e. to shoot a 5mm deep stack at 4x magnification, you move the rear standard 5mmx4 = 20mm.

My home-made setup has two stepper motors: one for the front standard, one for the rear. When I have the controller in rack mode, it moves both together.

Until now, I've never seen anyone else do computer-controlled bellows draw before.