Unfortunately, Swift model numbers sometimes get used for different products. This is a case in point. The orginal Swift 825 7x35 HWCF was designated the "Compact Audubon (Armored) - Wide Angle" (428 ft.). It used a 4-lens ocular and magenta fully coated optics with multi-coating on the ocular and objective lenses. There is no mention of it being phase coated, and we can safely assume it wasn't. It was sold at least until 1991. The current 7x36 Eaglet really isn't the same binocular although it's a similar configuration. To my knowledge it's not called an Audubon, which excludes it from such exclusive company (for us purists

). The Model 827 roof Audubon was sold into the late 1990s, and received a nice review by Steve Ingraham. I believe there is also another current Swift product model 827, but not called an Audubon. The current HHS 828 Audubon is a really neat, modern roof binocular with phase coating. It has received good marks from BVD, and I also recommend it highly as a moderate cost roof with adequate FOV.
The classic BVD comparison between the 804 vs. 820 Audubons has been confounded by the fact that there are two 804 models involved. Steve Ingraham's comparison in the early 1990s used model 804 HR/5 (Type 4b(1)), which was marked multi-coated optics (MC). The later 804 HR/5 (Type 4b(2)) was marked fully muti-coated (FMC) just like the current Model 820. Steve seemed to think the 820 was slightly better optically than the 4b(1). His opinion that the 804 ED (Type 4c) was also slightly better, and worth the huge price difference, was similarly blurred by the fact that the use of ED glass was not the only distinction; it was FMC and had air-spaced objective lenses to boot.
Steve Carter at Swift feels that both 804 HR/5 models, as well as the 804R, were fully multicoated (FMC). My own opinion is that even though expert reviewers like Steve Ingraham are highly credible, an unavoidable observer bias (e.g., that FMC, or ED glass,
should improve the optics) could easily account for the tenuous differences reported. There is a fundamental limitation to a methodology wherein an observer knows what the advertised design differences are before making subjective evaluations.
My personal
preference for the 804 vs. 820 is similarly biased by the fact that I really like the weight and balance, and solid construction of the 804R, and believe they are optically equivalent. As a collector, of course, I would buy an 804 ED if one came my way.
Basically, you can't go wrong with any of them.
Ed
PS. Renze gets the first 825 to come along — probably. :king: