An Open
Letter to The “Alpha” Bino
Makers
Dear Alpha-Bino Maker,
I have been getting through quite
a few “alpha” binoculars lately and something has been bothering me. Most of you
now charge thousands for your premium models and to me that means they should
be pretty well perfect. But they’re not.
For example, when I tested the Leica Ultravid HD 12x50 earlier
this year, I noted the following:
·
Not
enough eye relief to see the whole field with glasses on.
·
Some
residual chromatic aberration on high-contrast subjects.
·
Significant
field curvature from about 70% field width.
·
A
focuser which lacked the fluidity of the Nikon HGs.
In every other respect the Leica is a gorgeous, superbly engineered binocular. But
should I have to compromise at all
for a list price of over £2000?
If TeleVue can do it...
I would urge your R&D
department to try the following simple steps to improving your products:
1) Buy a TeleVue
NP101 or NP127.
2) Buy a TeleVue
Ethos.
3) Insert 2 into 1.
4) Observe.
5) Got out for a beer and discuss.
Seriously, though, if an NP127/Ethos
SX can deliver flat-to-the-edge performance with good eye relief, freedom from
blackouts and no visible chromatic aberration in a 110° field at 178x, why can’t a Leica Ultravid manage it with a 65° field at 12x?
This doesn’t stop with Leica, either, because even the Zeiss
FL doesn’t come close. The new Swarovision EL is the
nearest to my “two-small APOs” ideal, but it delivers just 60° apparent field
and is too small to be an ideal Astro’ binocular.
The
Challenge
So I challenge you to come up
with a good higher-powered binocular, say at least a 10x50, with the following
characteristics:
·
No
visible in-focus CA.
·
An
apparent field of 70° or more.
·
A
field which is sharp, flat, bright and coma-free to the edge.
·
Eye
relief of at least 16 mm.
·
Minimal
blackouts (spherical aberration of the exit pupil in technical terms).
·
A
focuser as smooth, fast and accurate as Nikon’s HG range.
·
All
the usual features, such as waterproofing, twist-up eyecups, etc.
Yours Sincerely
Scope Views
Addendum: I can hear the
arguments already:
“But an NP127 is F5.2, so it’s
easier to make CA free.” Yes, but it has a much larger aperture, so a similar
design for a 50mm F3-4 should be possible.
“But an Ethos is HUGE, it couldn’t be a binocular eyepiece.” Indeed, but to
achieve a 70° degree field, an Ethos is not
required: more like a Panoptic 15mm, which is small
and light weight.