BSA 10x50 binoculars arrive 9-29-03

They are very nice rubber coated binoculars but did have one
discrepancy noted. They are ruby color coated on the R1 surface of
objective lenses. The seller replied:

"Pete: I apologize for the error. I didn't realize that I received
a mixed case of those 10X50 binoculars from BSA when they closed up
shop in Ft. Lauderdale. The few remaining 10X50's I have are Ruby
Coated. I do have the green coated binoculars in the BSA armored
20X50's. Let me know what you want to do..."

The rear of objective and all the visable surfaces are fully coated
MgF2. The prism covers read:

BSA
10x50
FULLY COATED OPTICS
and
WIDE ANGLE
122M/1000M
367FT/1000YDS
D4-10X50WARA

Eye relief is approx. 10mm, focuser is smooth with no backlash, the
bridge arms are solid without flexure, the travel rod has some very
slight side play noted. The eyepieces remain nicely fixed for normal
fine focusing. The prism type is unknown but exit pupil is round with
exception of one shadowed edge shown in one optical tube. Collimation
is good and the binoculars are extremely crisp with high contrast. No
real noted chromatism at all even at perifery suggests good eyepiece
match to configuration.

The fact that the outer objective lens has a variation of ruby-type
coating on the single outer surface has very little effect against
natural coloration of image. A surprise to me as I've seen several
other variations of this type before and all had much more significant
image color shift toward green and away from red.

Pending clear skies I will evaluate and compare at night to others. I
know there is common belief any ruby looking coating binos are to be
avoided but there is no hard data supporting that notion. In fact, I
and others have found a particular pair of high quality Sigma 12x50
binoculars (same as older Celestron Pro series but with a ruby
objective) was highly useful to astronomy.

As odd as it may then sound, I certainly believe these BSA should make
perfectly suitable astronomy binoculars as any other would be since
they performed very well under daylight analysis and demonstrate
insignificant color shift. I personally feel the earlier Visioners
with flash green color objectives and noted "pinkish" image were more
obvious to show color shift even by day. There is some subjectivity
to this as others will prefer warmer toned views than this BSA model.
A bright moon will be a good test object to see how far from natural
tone these actually are to my eyes. I can say right now with good
certainty it's only to be very slight.

My initial impression is the BSA are very nice and that it is too bad
they are not going to be readily available. If deemed appropriate I
may send them to one or more well known and trusted individuals in the
astronomy community for further demonstration and comparative
feedback.

Clear skies,

Pete