|
68deg series
wide field eyepieces
Using advanced
computer design, combinations of low dispersion and high refractive
index optical glasses, and durable multilayer deposition coatings,
Explore Scientific 68° Series™ Argon-Purged Waterproof extreme
wide field eyepieces are optimised to produce high contrast, high
resolution, and superior flat field characteristics. The visual
effect of these eyepieces with their long eye-relief and their 68°
apparent field is truly a full-immersion experience. The 68° Series
eyepieces come with a removable and foldable soft silicone rubber
eyecup for the comfort of the observer, and as experienced
astronomers know, eye comfort is critical when trying to observe at
the visual limits of the telescope.
Protection from the
Outdoors - By making the eyepiece body Argon-purged, the waterproof
eyepiece internal elements will remain as pristine as the day they
were assembled.
Argon atoms are “
larger” than that of Nitrogen and therefore they are less likely
to “leak” or diffuse their way through the seals over the life
of the eyepiece. The atomic radius of Argon is larger than Nitrogen
by 0.13 angstroms and has a larger atomic volume by 11.2 cubic centimetres/molecule.
Argon also has superior inertness vs Nitrogen (i.e. forming few or
no chemical compounds with other elements) that prevents adverse
reactions with eyepiece components and therefore extends the
longevity of the internal components, and also prevents chemical
reactions with other elemental contaminants that may be introduced
through a weakened seal. And, finally because Argon is less
conductive of heat than Nitrogen, Argon cools slower thereby
buffering the effects of rapid temperature changes of the optics.
The sealed, dry
environment is impervious to internal fogging and contaminants such
as fungus growing in between the lens elements. Our waterproof
eyepiece is easier to clean, and there is no risk of cleaning
solution migrating from the top of the lens and seeping around edges
to be trapped in between elements. To insure a perfect seal we test
every eyepiece in one meter of water for 30 minutes.
Explore Scientific
68deg series eyepiece focal lengths
1.25" focal
lengths:
16mm, 20mm, 24mm $292ea
2" focal
lengths:
28mm $389ea
34mm $465ea
40mm $535ea
|
