Well Brock,
I expected an anwser of yours and I expected that it would contain as always, these terms: "Rolling Balls", "Holger", and "Nikon".
To be honest, it's really not that easy to find one of your messages that doesn't contain these words.
The birders I mentioned weren't only Germans. I'm pretty sure that any uninfluenced (!) scrutiny about "RB" would come to the result that it's rather a small minority that sees it. Feel free to do this by yourself! But take into account these experiences I made. I gave several test persons the SV and asked them if there is anything special when panning with them. The regular answer was 'no!' In a second step I explained them the theory of RB and ask them to pan again. Then - surprise - about two of 10 did say that there could be 'something'. Now the question is: did they really see RB or was it just my explanations that made them see it (or 'something')?
Unfortunally I don't have that much time to get too deep into what I feel is a side issue but here are some short remarks about facts that in my opinion should taken into account when dealing with the rolling ball effect and that AFAIK you, your Holger and others did overlook so far.
When panning it does matter, what your are looking at when using binoculars. Like Horst Koehler wrote in "Die Fernrohre und Entfernungsmesser" which is until today considered among experts around the world as some kind of "bible of optics", RB could be visible (only) when looking at spacious objects. IMO even more important, when assessing the questionable phenomenon is the question which type of optics did a person use to use before trying e.g. the SV. Visual perception is a highly adaptable system that depends to a high degree on experiences of a person. Looking through binoculars or telescopes is always different from natural "naked eye use", amongst others just because of the difference in magnification. So if someone feels that a piece of optics gives him a natural view that means that he had adapted to the optics before. Since the 1950s there were almost only binoculars with noticable pincushion distorsion that came on the market. For decades most users had adapted to this distorsion. This kind of anamnesis does play a role when someone is using binoculars with none or a low degree of (pincushion) distorsion for the first time. My findings seem to indicate that frequently users of one exclusive instrument with a high degree of pincushion distorsion (e.g. Zeiss Victory Fl) tend to see the RB rather than others who e.g. use different types of binoculars.
Now believe it or not - I know someone who has seen RB in fact - and that was me myself. :eek!:
No RB for me with the Nikon HG/Premiers, the 10x42, 10x50 and 12x50 SV or whatsoever. But when I used the 8,5x42 SV for the first time, looking and panning at a spacious and uniform border of a wood I saw it - for just about 3 seconds! Then it disappeared ever since and did not come back one single moment. What did happen during these 3 seconds? I think my visual perception did adapt to the binoculars. My conclusion is that RB or as we perhaps should better say "apparent movements within the image while panning with binoculars" is a matter of the brain rather than of the eyes. Now - enough at this point. Perhaps this is an opportunity, Brock, to leave the everlasting circles of repetition (RB, Holger, Nikon etc.) and to try something new. For me it is so tiring to read again and again the same terms and about the same subjects. In addition repetition does not transform an obsession into something meaningful...
Steve
Repetition is the death of art.
Robin Green