Copied over from the other thread and edited to stay more on this particular topic.
I think the hero ESB is an anomaly..for whatever reason, but to me, it has a flare the other helmets do not, or at least do not as much. You can see it pretty clearly in these shots:
Recent pics of the hero helmet may appear not to have it but i think thats because most of those pics are taken fairly close up, and the lens def distorts the look when your that close. I know this because my helmets also have a bit of flare on them, but if i take a pic of it fairly close up, it gets lost in the photo. I have to take a pic from a few feet away, zoomed in for you to see it, just like in those screen shots above i posted.
Also i agree with you @
intwenothor /Andy that the flare is not hugely significant overall. When you look at the FPH2 in person it doesnt scream out "oh look at that flare" but when the ears are on and you step back, looking at it in the slightly chin up position, its there enough to notice. Someone on the Pathfinder/bikerscout boards once said the human eye can see 1mm of difference in something, even if we dont know exactly where we are seeing it..we can just see something is different. Using that logic, i really think thats what it is. When i added the flare on my MR casts, i think i added 1/4" to the overall width which is only 1/8" on each side...not much at all...but when looked at at that same chin up angle, i see the flare, which is why im likely leaving the flare as is and will only make those other changes i mentioned if i ever get around to it lol.
For example, this is one of my casts taken from a few feet awayand it was on a shelf higher than me, so it is slightly chin up..and the photo is zoomed in and cropped
Now, in this picture, im wearing one of my casts as well, and i dont have my chin up lol..the flare isnt really noticeable here
But in this picture of my wife and her sister where im in the background..even though you can't see my whole head..it is taken from slightly lower and looks like it has more flare/width to it.
Thus really proving your point, its all about the angles/distance from a camera. I do feel the standard MR does in fact have a more straight angle on ears though. This may be a product of the pinched visor though..as if you take an MR, remove the visor and pull the bottom open to make the visor opening even...that touch of flare returns.
So my thought is, its there on all the helmets, but not as prominent as some may think. You never really see an angle of the ROTJ helmet quite like that dining room shot in ESB.. also Jeremy was super thin in ESB so that also can make the helmet look wider in general. He bulked up a little for ROTJ which in turn would make the helmet look less wide as well.