Hi,
If you read Holger Merlitz's article the mathematical foundation for a standardized formula is presented, which is based on his work. Like all science, however, it's open for scrutiny and I suspect may be confirmed or refined by others. In any event, I don't know if ISO will weigh in, or should, since binoculars are currently designed within an adaptable range of distortion, and it's not a measurement issue.
There are several known perceptual phenomena, symptomized by dizziness, disorientation, or nausea, which could easily be induced using binoculars and misidentified as the globe effect. In fact, with so many people looking for "rolling ball" nowadays, I wouldn't be too surprised if a huge proportion of positive findings were actually due to this. We are, after all, simply a bunch of untrained human observers believing that everyone reporting "rolling ball" is experiencing the same thing under uncontrolled observing conditions.
Ed
I've read it several times & have attempted to get as close to the laptop screen as the bar
graph shows w/limited success. One can have their eyes examined for the need/strength of prescription glass and the DMV has you read a few lines of letters, both eyes open, and then go through a series of peripheral red flashing lights, left/right/both. So, I thought how nice if the same would apply to binoculars using Holger Merlitz's diagrams/templates of various degrees.
I don't have to look for the globe effect/RB as it's evident enough, especially in a horizontal pan, as images appear to come closer in the center/
foreground and then fade into the
background. I know the
movement is my perception. It doesn't bother me and I consider it welcome, when viewing in dense woods, over some aggressive PC movement that's reminiscent of the spooky talking trees from, The Wizard of OZ.
I have some cheap Japanese built 10x50 w/262' FOV that are a pin cushion nightmare putting the 7x36 EDII to shame in the distortion race. They'll bend tree or telephone pole to a bow. I can look at a jet vapor trail, relatively low & straight in an ascent, looking up in a scan and through the plane produces a frown and back down a smile almost on the order of your basic 180* 6" compass it would seem.
These compress the middle so much that the extreme PC, @ 10x w/narow FOV, undulation somewhat mimics RB. Viewing woods in a vertical scan gives the illusion of tilting the entire picture one way for up and the other for down. This looks close to the 8x42 Caldera, in the middle eyepiece position, view. However, w/Caldera mild RB there's no curving/distortion to speak of and the picture is relatively flat.
Also, it seems to me that binoculars are designed for close in/far away or a combination of the twain. Maybe this is influenced by magnification, FOV and/or lens curvature, but some w/lot of PC, that I've looked through anyway, tend to amplify the PC in close range and diminishes greatly over distance.
Is it PC, lens curvature or both that shows pine needles, at a distance, dancing on the edge/top of the view whilst panning L-or-R? I tend to conclude, & that within it's self is a scary thought, that it's mostly the curve. I thought PC @ first w/ambitious FOV, but pine needles in the Caldera don't dance at all. Also, the 8x30 & 10x40 Conquests that have been reviewed we/lot of distortion/PC don't exhibit this trait. The top of pines through the EDII looked as if they were dancing the hula. Yet, if I didn't look at that edge or look at woods inside of 75 yds they were expansive w/clean colour & sharp view.
W/better glass these days around $300-$500 & up it would be nice if you could be measured and have glass rated to give you an idea of what style & how much of the mix that you might prefer. Maybe not practical, but nice.
For what it's worth I no longer see the same amount of RB in a pan w/Caldera. It's now like I described when fully extending the eyepieces. I see undulation,yet the objects no longer jump closer in center view. As near as I can tell the vertical is still the same & it's pleasant. The mild RB is clearly outweighed by the straight/distortion free. for the most part, view.
Sorry for being all over the board as I certainly have no intentions of hijacking your thread.
