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

On Mon, 29 Sep 2003 18:45:14 -0500, Pete Rasmussen
wrote:

As update on the BSA 10x50...

The seller has emailed a very interesting remark in opinion to bolster
their prowess. His _is_ unbiased and to the point in this particular
case:

"Pete: You don't want the [another label brand bino available].
They're not even close to the quality of the BSA's."

BSA 10x50 used briefly at night:

I took my pair out under clouded (yet transparent in gaps) sky
conditions for a few minutes. The binoculars snap impressively to a
seriously tight focus. Very sharp optics. The field is approx. 66%
sharp toward edge and then the brighter stars begin to extend evenly
and become less apparent toward the edges. This vs. them elongating
and remaining distractively bright on the perifery. This is a good
thing and I did not anticipate exceptional edge sharpness for these
low end binos since having an extra-wide apparent field angle by
design.

The field is flat and undistorted and sweeps of available star fields
were satisfactorily breathtaking with very nice sky contrast.
Brightness is good for these. There was a bit of field edge
vignetting shown to evenly remove field stops visability. That
happens sometimes and was not the case by day. I've experienced
similar with Ultima 7x50, Orion Mini Giant 11x70 and others before,
too.

The crescent phase moon was partly veiled by semi-transluscent clouds
and was low in the western sky just above tree line. This is where a
wide-angle bino can be nice since all is viewed together to create a
panorama in perspective. The focus on the moon was acheived instantly
and was razor sharp and clear. A very fine view especially with
earthshine to add additional effect.

Bright areas of the moon itself seen between clouds looked very white
and closely the same as was seen naked eye. However, there was a hint
of orange tint detected when viewing naked eye. This due dust in our
atmosphere. So that rubesque coating worked to my favor to remove it!

Last up my nemesis streetlight showed there was significant ghosting.
Most binoculars show some or even a lot under this tough as nails
test. However, when the powerful light was placed anywhere just
outside of field, there was no real glare at all and faint terrestrial
objects in the background were easy to see.

These are keepers for $23! When indoors looking at the ruby type
coating again at narrow 25° incident from direct, they disappear and
the inside of the binos then easy to see transparently just like
multicoatings do.

That was fun I hope you had fun too!

I would have really enjoyed getting the BSA with green coatings just
to do a decent direct comparo on deep sky FOR THE RECORD and to
DISPELL that RED MYTH! Too bad they're gone, oh well.

The $38.88 sale priced Whitetail 10x50 I also announced is probably an
even better buy than this BSA due long 19mm eye relief and indicated
better edge sharpness. Would be swell if someone getting some in
would report to us soon.

Take care, clear skies and ruby red eyes!

Pete

Pete,

Pete Rasmussen wrote:

The $38.88 sale priced Whitetail 10x50 I also announced is probably an
even better buy than this BSA due long 19mm eye relief and indicated
better edge sharpness. Would be swell if someone getting some in
would report to us soon.

I did get a pair of the Whitetail 10x50 and did a quick daytime check of
them. Unfortunately, the night before my wife was to take them to the
lucky young recipient of these binos (one of her students) I saw nothing
but clouds when I went outside to test them on the night sky. So I can
only say a little about their daytime use.

I compared the Whitetail with Bushnell Explorer 10x50 that I acquired in
the 1970s. These were Bushnell's top of the line at a time when their
good stuff was highly regarded. The center of the field might have been
a tad sharper in the Bushnell and the field was clearly wider in the
Bushnell. The field of the Whitetail stayed sharp at least 2/3 of the
way to the edge of the field, however, in contrast to the Bushnell where
the sharpness seemed to suffer with almost any deviation from the
center. Edge performance was quite acceptable.

Eye relief was comfortable even with glasses (with the rubber eye cups
folded down). There was a slight problem with blackout (or kidney bean)
but only just a bit. This might be at least partly due to my lack of
experience observing with glasses on (I usually wear contact lenses).

Focus was easy to achieve although there are separate focus mechanisms
for each eyepiece and no center focus, which I dislike intensely (but
that's just my personal preference). Maybe this isn't a problem for
astronomy since you stay focused at infinity but I wouldn't know since I
won't buy binos with that arrangement.

A quick look at solar reflections from the front lenses indicated the
internal surfaces were not coated. I'm no expert on coatings, though.
Coatings were perfectly uniform with no blemishes. Color was a light
purple, I think. I was able to see a thin arc of reflected light --
looked like the edge of a lens element -- when looking close to the Sun
but this required looking past the edge of the field so it didn't
represent a problem. I noticed no other reflections when using them.
Baffling looked good to me and the interior of the tubes were lightly
grooved and well blackened.

Color was good but I didn't check this out very carefully. Color
correction was excellent during the day. I wanted to check this at
night, though, and didn't do an extensive examination of this.

Exit pupils were sharp and round. Collimation was good but I would have
preferred to test this on a star. They were comfortable and easy to
handle.

All in all a great bargain. Are they good for astronomy? I hope
someone else gets a chance to test them out at night.sigh But I
suspect they'll be very good performers, especially considering the
bargain price.

Mike Simmons

Mike Simmons wrote:

Pete,

Pete Rasmussen wrote:

The $38.88 sale priced Whitetail 10x50 I also announced is probably an
even better buy than this BSA due long 19mm eye relief and indicated
better edge sharpness. Would be swell if someone getting some in
would report to us soon.

I did get a pair of the Whitetail 10x50 and did a quick daytime check of
them.

Unfortunately, they are back to $60.00 and now with a comment of their
Pentax origin. SAA working ;-0 ?

David