First of all: Your pics (K2Kraze and Rubik's) are great. I know: Once you are deeply involved in a hobby you always strive for perfection. However, I don't think there is more than a 5% improvement to be gained in most of your pics. So - you'll have to decide if it is really worth it. If it is just a "hobby challenge", go ahead. But I don't really see a need for even better quality - unless you want to use the pics in a book or something like that.
Back to a few things you talked about:
1) A shaped tray. You could do that - I think - by inserting a regular one in hot water or using some kind of hot air blower to bend it to your needs. However - two drawbacks come to my mind. It will only work with one specific lens perfectly if you tune it to that one. And it will be unstable so you would also have to create some sort of support so it doesn't wobble.
2) If you want to get distortion completely out of the pictures easily, I would either go the telephoto route (BTW a fixed focus lens is always better than a zoom) or you could use dedicated software. I know you can do it all in Photoshop or Gimp. There are some - even free or shareware - software packages which are even easier to handle. Sadly, my old computer died a year ago so I can't look what I used to use back then. It was a really easy to use shareware software which got the distortion out of pics with 2 or 3 clicks once you saved the parameters for different lenses. I used it mostly for extreme wide-angle pictures. The last step was always a slight crop and you could not tell that software did the trick.
If you search for something like "lens distortion correction software" enough stuff should come up. I found this page for example. A little further reading might be advisable:
https://listoffreeware.com/best-free-lens-distortion-correction-software/
You hit upon two key points and personal hot buttons for me, Meucciplayer - chasing perfection (an enjoyable pursuit), and the goal of having pictures worthy of a reference book and large format prints. Very large. Borderline hobbyist venturing on fanatical attention to detail. You know - the fun stuff
Agreed on every point you’ve made - from lenses to techniques. And that is where the magic lies......blending the elements to achieve one’s desired result. The art of it all. In short - The passion. Hard to explain, but understood and acknowledged with a simple head-shake between those of us that know.
Thanks for the link - and ideas, sir! I’ll stay the course and see what magic I can create
~ K.
Oh - one last thought regarding edge distortion: let’s say we did have some specialty concave photo board made - wouldn’t we still have the balls at their furthest edges slightly distorted? Looking at the 12 ball in a typical tray let’s say, the further you look from the dead center of that 12 ball, it will appear to be a bit oblong. It would be minimized, yes, but it’s always there due to the nature of the lenses at close range. I’ve experimented with similar layouts having balls on the outer slots a tad higher, angled, and turned slightly toward the camera, with similar distorted images when you look closely. Again, it’s better and minimized - but still present.
Ok - Time to contact the folks at Nikon and get their thoughts. See what they’d use and how to do it.