Oh boy, this is still going on.
There is a new patent law passed in 2013 in the US that essentially make it very hard for many patent holders to enforce it. The new law says if anyone who can find a prior art, not just well known, well published one, it will be enough to invalidate patent. I think there is a case that one patent holder won a multi-million dollar case, only lost in second case because the lawyer in second case found a paper published in Iceland (or Belgium), but only available in the school library, even that, with the new law, the patent holder lost the second case.
I certainly believe there were many prior arts of focus stacking out there before the patent. I myself have done work for a research institution on this in 2008 and wrote a stacking algorithm that was comparable to then state of art product -- my algorithm produce many similar results as well as artifacts. So the concept of focus stacking is NOT invented by the patent holder, in another words, the patent could not be interpreted to cover the concept of focus stacking.
Also, to test my algorithm, I built an automated system, though different from what is described in patent, it shows the concept of automated focus stacking is and was NOT new. The whole setup was demonstrated in a developer conference in Seattle sponsored by a well know company in the industry.
Even without my setup, I am sure there were many cases of automated focus stacking.
As Chris S. points out, the patent is a utility patent, being that, most utility patent must be very specific and novel, it can not cover a concept, but it does cover how a specific concept is done.
Having said that, even with the new patent law, I do believe the patent has its own novelties -- its construction, its look and feel (utility patent does cover design patent), and most importantly, the implied trademark. I bet when most of members of this forum will say "ah, it is a stacking machine" when they see the patented product. I, respectfully, admit that the patented product is a SYMBOL of this specific area despite the fact the patent is an obstacle for me (to market mine).
However, if you look at my design and look and feel, it is totally different from the patented product. I have intentionally avoided the look and feel of the patented product. Being Chinese American, I hate people telling me I stole the ideal and I am a copycat, so I designed it differently (and with added benefit: to take advantage of a key industrial component, the linear guide rail for precision). I do not
want people say "ah, that is a focus stacking machine" because it looks and feels like the said patent. My design is sufficiently different from the patented design. Also, I have never used the name of patented product in my advertising material, not in English, not in Chinese. All these were thought out even before I was hit by the email from lawyers of the patent. All of my ads were geared toward making people know that "this also is a focus stacking machine".
One last note, this is why I allow people with the patented product in my facebook group because I do have respect for their work and idea, particularly the image they have built over the years (like people use Xeox). I kept those copycats out of the group because I think those are truely violating and taking advantage of the image of the patented product (hey, wanna buy a Rolex on the street); those which uses the name of patented product (such as the term "comparable to") in their business material or shop; and those which one can say "oh, it is a copy" of the patented product. It is a shame to support those who uses a product that takes advantage of the well built symbol of this area (do you like people who wears a fake Rolex?). Of course, other reason like sales tactics, but that is different topic.
As Chris. S pointed out, the patent still has value -- prevent sales in US, prevent retail stores to carry other similar products as they do not want to fight it. But if challenged in court, I do not think the patent will hold, this is my personal opinion.