Orion 8470 User manual

INSTRUCTION MANUAL
Providing Exceptional Consumer
Optical Products Since 1975
OrionTelescopes.com
Customer Support [phone]
E-mail: [e-mail]
Corporate Offices [phone]
89 Hangar Way, Watsonville, CA 95076
© 2015 Orion Telescopes & Binoculars
IN 450 Rev. B 03/15
Orion®High-Power 4-Element
Barlow Lenses
#8470 High-Power 1.25" 2x 4-Element Barlow
#8707 High-Power 1.25" 3x 4-Element Barlow
#8715 High-Power 1.25" 5x 4-Element Barlow
#8471 High-Power 2" 2x 4-Element Barlow
Orion 1.25" and 2" High-Power Barlow lenses (Figure 1) boost the
magnifying power of any telescope eyepiece they are used with. With
different models featuring magnification factors of 2x up to 5x, these
premium-quality Barlows get you closer to your telescopic target, be it a
planet, the Moon, or a deep-sky object. Their exceptional optical quality
and mechanical craftsmanship will appeal to the discriminating amateur
astronomer who wants only top-notch performance from his or her
equipment.
Figure 1. The Orion High-Power Barlow Lens series includes the 2” 2x model and
1.25” 2x, 3x, and 5x models.

High-Power Barlows work by reducing the convergence of the light cone heading into
the eyepiece. The Barlow effectively increases the focal length of the telescope, thereby
increasing the magnifying power of any eyepiece used with the telescope and Barlow:
telescope focal length X Barlow magnification = total magnification
eyepiece focal length
Features of High-Power Barlow Lenses
High-Power 1.25" Barlows fit standard 1.25" accessory holders and are used with 1.25"
eyepieces. The High-Power 2" Barlow fits 2" focusers and accommodates 2" eyepieces.
The 2" Barlow includes a separate 2"-to-1.25" adapter that allows use of 1.25" eyepieces
and accessories (Figure 2). When it’s removed the 2" collar is available for use with 2"
eyepieces or accessories.
Each High-Power Barlow lens has an enhanced 4-element lens design that minimizes
chromatic and spherical aberrations and preserves sharpness and contrast. Images
appear flatter, sharper, and better color-corrected than with standard achromatic
Barlows. And with a High-Power Barlow you get the full benefit of the longer eye relief
typical of longer-focal-length eyepieces, versus using a shorter focal length eyepiece to
achieve the same magnification.
Figure 2. The 2"model includes a 2"-to-1.25"
adapter to accept 1.25"eyepieces.

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Figure 3. Mechanical features of High-
Power Barlow Lenses (shown for a 1.25"
Barlow)
Figure 4. The end of the barrel has
female threads that allow use of Orion
1.25"(shown) or 2"filters (depending on
the barlow size)
1.25"
barrel
Brass compression ring
Filter
threads
Thumbscrew
Rubber grip
Safety slot
Machined from solid aluminum, High-Power Barlows have a grooved, grip-friendly rubber
exterior on the housing (Figure 3). A brass compression ring secures any inserted
telescope eyepiece in place without marring or scratching the barrel, keeping your
eyepieces like-new. The 2" Barlow has two thumbscrews for securing an eyepiece while
the 1.25" Barlows have one thumbscrew.
High-Power Barlows’ lens elements are fully multilayer coated with anti-reflection
coatings, and edge-blackened to provide maximum light throughput and optimal image
contrast. The 1.25" and 2" barrels (depending on model) are internally blackened and
glare threaded to help prevent internal reflections from reducing image contrast. The
barrels have a recessed safety slot to prevent the Barlow from falling out should the
locking thumbscrew become loose during use. The barrels are threaded at the end for
use with Orion 1.25" or 2" filters, depending on the model (Figure 4).
Use of Orion High-Power Barlows
For refractors and Schmidt-Cassegrain telescopes, you can insert the Barlow between
the diagonal and the eyepiece or between the focuser (or visual back for SCTs) and
the diagonal. For reflectors, place the Barlow into the eyepiece holder of the focuser
drawtube, then insert an eyepiece into the Barlow lens.
CAUTION! When inserting a Barlow into the eyepiece holder of a diagonal, be aware that it
could “bottom out” on the diagonal’s mirror or prism before it is fully inserted! Use extreme
caution to avoid marring or cracking the mirror or prism with the barrel of the Barlow. If you
feel the Barlow touch the mirror or prism, carefully back the barlow out a bit before securing it
with the diagonal’s thumbscrew(s).

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One-Year Limited Warranty
This Orion High-Power Barlow is warranted against defects in materials or workmanship for a period of one year
from the date of purchase. This warranty is for the benefit of the original retail purchaser only. During this war-
ranty period Orion Telescopes & Binoculars will repair or replace, at Orion’s option, any warranted instrument
that proves to be defective, provided it is returned postage paid to: Orion Warranty Repair, 89 Hangar Way,
Watsonville, CA 95076. If the product is not registered, proof of purchase (such as a copy of the original invoice)
is required.
This warranty does not apply if, in Orion’s judgment, the instrument has been abused, mishandled, or modified,
nor does it apply to normal wear and tear. This warranty gives you specific legal rights, and you may also have
other rights, which vary from state to state. For further warranty service information, contact: Customer Service
Department, Orion Telescopes & Binoculars, 89 Hangar Way, Watsonville, CA 95076; [phone].
Power Limitations
While a Barlow lens will increase the magnification of a telescope, there is a limit to how
much magnification is useful. It depends on the telescope’s aperture, the quality of the
optics, and on the outdoor “seeing” conditions, which vary from night to night. Keep in
mind that using the 3x or 5x High-Power Barlow may exceed the maximum practical
magnifying power of your telescope and eyepieces.
Generally, the maximum practical magnification a telescope can deliver is about 50x per
inch of aperture (diameter of the main lens or mirror). Any higher and the images seen
will likely just be blurry and dim. Seeing conditions (i.e., steadiness of the atmosphere)
often limit the useful magnification to much less than 50x per inch of aperture. If you are
using a High-Power Barlow for planetary imaging with a webcam or special planetary
camera, you can benefit from “oversampling” by increasing the magnification higher than
you typically would for a sharp image. Digital processing will allow you to sharpen the
image and reveal extraordinary detail.
Care of Your Barlow Lens
Care should be exercised when using all optical and mechanical telescope accessories.
Keep your Barlow in a protected environment when you’re not using it. Avoid touching
the lenses and coatings. If the outside of the lens should become dirty, you may want
to clean it. Blow off all loose dirt with a blower bulb. Use only optical lens tissue and
good-quality lens fluid. Wet a folded tissue and gently wipe the surface of the lens.
Immediately use a second piece of lens tissue to gently dry the lens off. Do not rub or
apply pressure, as this may scratch the lens if dust or grit is present.
It is recommended to keep the plastic plug in the top of the Barlow and the cap on the
end of the barrel when the Barlow is not in use.