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Starlight Instruments Single Deep Red Beam 1.25" Laser Collimator - 650nm |
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Starlight Instruments Single Deep Red Beam 1.25" Laser Collimator - 650nm
Starlight Instruments Single Deep Red Beam 1.25" Laser Collimator - 650nm
Item# SISI-LC125-650
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Starlight Instruments Single Deep Red Beam 1.25" Laser Collimator - 650nm - Single deep red beam operates at 650nm for night time use.
- The Howie Glatter Holographic Laser Collimator incorporates a solid state laser diode that does not fade or change with time and use.
- Factory-aligned to 15 arc-seconds providing 0.1 inch accuracy at a distance of 20 feet,
- The Howie Glatter Laser Collimator is shock resistant to keep its alignment - even when dropped.
- Includes 123A lithium battery, 1mm aperture stop, removable diffractive element, case, collimation rings and instructions.
Howie Glatter Single Deep Red Beam Laser Collimator 1.25" 650nm
When it comes to lasers and collimation, one of the most trusted
names in the business is guru Howie Glatter. His uncompromising quality
and dedication to above average products, not only put his name above
the rest - but in demand as the finest available on today's market.
Usually a manufacturer doesn't take the time to explain to a customer
exactly why their product excels over others - or why it performs better
- but not Howie. Here's what he has to say about his new Howie Glatter
Laser Collimator:
"The lasers in my collimators are class IIIa lasers (maximum beam power:
5 thousandths of a Watt), and are quite safe if used with reasonable
precaution. Direct or mirror-reflected eye exposure to the laser beam
should always be avoided! You must be careful when collimating to ensure
that the beam does not enter anyone's eye. There is no problem in
viewing the beam's impact directly on a surface as long as the surface
produces a diffuse reflection. The beam impact may also be safely viewed
on a mirror or lens surface if the reflected or transmitted beam is not
directed towards your eye. Information from studies I have seen
suggests that in order to induce permanent damage, a class IIIa laser
beam must stay focused on the retina for a long time. It's unlikely for
this to happen because the pupil is a very small target and because we
have a blink and aversion reflex to bright light. However, all
precautions should still be followed to avoid the beam entering anyone's
eye! A badly miscollimated Newtonian or Cassegrain telescope may allow
the beam to exit the front of the telescope, so when collimating, check
first by pointing the telescope at a wall or screen to see if the beam
is getting out. With unobstructed telescopes such as refractors, the
beam will always exit the front of the telescope, so run a strip of
masking tape across a diameter of the dew cap opening as a safety beam
stop.
Inside the collimator is a solid-state laser diode, which emits an
intense laser beam through a front aperture, exactly along the central
axis of the cylindrical collimator body. The beam acts as a "reference
line" from which alignments are made. For a laser collimator it is of
supreme importance that the beam be aligned with the collimator's
cylindrical axis, for if it is not, the resultant "alignment" of the
telescope optics will be off-center and asymmetric, and the telescope
will produce aberrated images.
When I started manufacturing laser collimators I realized that in order
to produce consistent and accurate results they must be highly resistant
to mechanical shock, so that internal laser alignment is maintained. I
experimented with this aspect of collimator construction and developed a
design which tremendously increased shock resistance. After aligning
the laser within 15 arc seconds, I shock test each collimator by
whacking it against a block of urethane plastic (urethane prevents
marring), striking it at least a dozen times on three axis. I then
recheck the laser alignment, and if it has not changed the collimator
passes. I believe this is the most important difference setting my
collimator apart from all others I know of. They will withstand a shock
equivalent to dropping from eyepiece position, up the ladder on a big
Dob, without alteration of laser alignment.
The beam from all red diode lasers used in collimators is fuzzy-edged
and elliptical in cross-section. When collimating, you sometimes must
judge the location of the center of the spot by eye. To improve
collimating precision, all of my collimators (except 532nm) are supplied
with a removable accessory plastic aperture stop having a 1mm hole,
which push-fits into the laser aperture. It produces a tiny, circular
beam impact which allows more accurate alignment. With the holographic
collimators, it is not used at the same time as the holographic feature,
and the diffractor must be removed to install the stop. With the stop
inserted the beam impact at a distance of one meter or more looks like a
star diffraction pattern, with a central dot surrounded by diffraction
rings. The surrounding rings can help in centering the beam very
accurately.
I offer the red holographic collimators with a choice of either 650
nanometer or 635nm wavelength. The two lasers have the same radiometric
power output, but because the human eye's sensitivity to the shorter
wavelength is greater, the 635nm. laser appears about two or three times
brighter. The higher cost of 635nm laser diodes increases the
collimator price, but it enables holographic collimation in brighter
ambient light. If you intend to collimate in early twilight, it is a
good choice. In darkness, however, the 650nm laser is quite adequate.
Because single beam collimators concentrate all the laser light in the
central beam, the 650nm laser is quite adequate for them."
Precise... Accurate... and Durable... What more could you ask?
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