Ardy,
Many amateur astronomers who use binoculars for stargazing are even more obsessive than you are in testing edge sharpness, which they measure in thousandths of arc seconds. That is, comparing the center field resolution to the resolution 50% out, 60% out, 70% out, 80% out, 90% out.
Although those optics experts also measure specs for accuracy (many bins have different apertures or magnifications or ER figures than advertised - often less than the advertised specs), edge performance seems to be the Great Obsession of binocular astronomers.
So if you are interested in edge performance, I recommend you check out the Cloudy Nights bin forum, and in particular Ed Zarenski's technical reports, which can be found by clicking on the link above the forum for "Technical Reports".
Of late, he and others on the site have been reviewing smaller aperture bins, including those used by birders, so you might find it interesting.
And who knows, you might start using your bins to look at the stars if for no other reason than that stars provide the best test for edge sharpness.
Often to achieve optimal edge performance, FOV is sacrificed, something that most birders would not like. For example, one of the most revered (and expensive) astro bins was the Takahahsi 22x60 fluorite binoculars which has a 2.1* FOV.
But many amateur astronomers use relatively inexpensive big binoculars from China. As long as stars are reasonably pinpoint and the edges are decent, no big deal about the rest since they mount their bins, focus them at infinity, and except for some bright colorful stars and a few planets, most celestial objects lack significant color and appear bluish white through binoculars.
Birders have a whole different set of criteria to measure and obsess about than amateur astronomers, though edge performance seems to be creeping into those criteria of late, with an increasing number of birding binoculars offering sharp edges by using various design approaches - limiting FOV (Brunton Epoch, Minox HG, Celestron Regal LX) or compromising with a moderately wide FOV (Leupold 8x42 Gold Ring, Nikon 8x32 SE) or using field flatterers to achieve a bit wider fields with sharper edges (Nikon EDG, Swaro SV, Meopta B1?).
Compared to hunters, birders are considered "anal" about their optics.
Here's a choice quote from a hunting forum:
"Check out the Birding Forums and Review sights. Those Bird watchers are usually a real good source of info on Binoculars and spotters. They are super Anal."
The original source (post #14):
http://www.huntingbc.ca/forum/showthread.php?p=589419
Not all birders are "Super Anal", and with more high end bins being marketed toward hunters, there are more hunters with deep pockets joining the "Super Anal Club".
However, there are BF members who you never see or rarely see on the bin forums, but who post regularly on other BF forums.
They are more interested in IDs, taxonomy and nomenclature, life lists, migrations, conservation, bird feeding, digiscoping and wildlife photography, birding conventions, conferences, and trips, and birding clubs than they are reading about binoculars and testing them.
They are out there birding, using their old trusty Zeiss 7x42 or 10x40 B/GA, 804 Audubon, 8x SE or EII, Leitz 7x35, Bausch & Lomb 8x42 Elite, or maybe something "newer" like the Nikon 8x42 Venturer LX.
Or they might have deep pockets and own the latest and greatest from the Top Three - many birdwatchers are middle aged, which in part explains the trend toward increasingly expensive binoculars, which younger folks can't afford.
I think a lot of these avid birders would find our optics talk as obsessive as I find their interest in IDing and photographing subtle variations in a species (except as a test of a bin's contrast and color depth
.
So there's a range of birders, from one end of the spectrum to the other. On one end, there are those who see bins and scopes merely a means to an end, and on the other extreme are those who see optics as an end into themselves and birds as an interesting target to use and test their bins.
I fall into the Super Anal group. I will have to stop here because I have to take a suppository.
