The collimation screws
(one pair of three)
The collimation screw
(taller)
The lock screw
(shorter)
the shorter of the pair is the lock screw that holds the proper
collimation after adjustment. Be sure to adjust only one
set of collimation screws at a time. Loosen the lock screws
before attempting to turn the collimating screws. Make only
small changes at a time (turning the collimating screw only
a fraction of a turn and checking to see the results before
turning further).
When you finish adjusting the collimating screws, be
sure to snug down all lock screws to hold the correct collimation. Do not over-tighten the lock screws, but make sure
they are firmly in place. Once collimation is complete, your
objective lens will be on the same optical axis as the eyepiece, camera, or CCD, and you will obtain the best possible optical performance.
The other method of collimation is to examine a first
or second magnitude star image at high power at night after the scope has reached thermal equilibrium. This collimation method requires an equatorially-mounted scope and
a motor drive to keep the star image centered while you
adjust the collimation screws. It is generally a more difficult and time-consuming collimation method than using a
Cheshire eyepiece, as you are working with a small and
droppable Allen wrench in the dark and are at the mercy of
changing seeing conditions.
Be sure not to choose a closely-spaced binary star as
your test star. Do not use a star diagonal when collimating,
as you may be attempting to correct a problem in the diagonal, rather than in the telescope. Adjust the push-pull
collimation screws until the star images are tight and round,
and the first and second diffraction rings are uniform in
their intensity all the way around the Airy disk.
THE ST AR TEST
We strive to make the best apochromatic optical systems available. You may find your lens may not test “perfect” during an extended and stringently-graded “star test,”
particularly if the scope has not fully reached thermal equilibrium before the test. This is not an indication of a poor
optic. It is rather due to the test star’s complex wavefront
of light that is being constantly changed by our living atmosphere as seeing conditions vary from minute to minute,
from second to second.
No optic is perfect and likewise, under a detailed and
extended star test, every telescope optic will show some
error. The sensitivity of the star test under perfect condi-
tions is 1/20th wave P-V on the wavefront for third order
The lens cell
Lens
aberrations, and 1/60th wave for sharp (fifth order) aberrations. It is highly unlikely that even the most ardent observer can see errors of this small a magnitude, even under
very good seeing conditions (which is when the atmosphere
typically presents a 1/4th wave P-V wavefront to the telescope and eye).
Something else to consider in star-testing refractors:
the change in spherical aberration with a change in wavelength. This is called “spherochromatism” and is found in
the wavefront of all refractors. What this means is that as
the lens is tested in the longer (red) wavelengths, the lens
becomes “under-corrected,” and in the shorter wavelengths
(blue), the lens becomes “over-corrected.” These overlapping corrections at different wavelengths change the star
test pattern from perfection.
So, while star tests are interesting and useful, most observers spend their nights enjoying the heavens, not just
examining points of light. W e feel that the proof of optical
excellence is in the observing, not just in the testing.
All TMB objectives are corrected at the peak visual
wavelength, which is centered at around 560nm in the
green-yellow portion of the visual spectrum. The eye sees
over 80% of the visual detail at this wavelength, and it is
the proper correction at this visual peak that makes the
difference between just a good objective, and a superb one.
We design and figure our lenses for the best possible
wavefront at the green-yellow wavelengths, to give you
the sharpest images and highest contrast possible.
A FINAL WORD
W e thank you for your purchase of this TMB-130. We
believe that this apochromatic refractor will outperform
any other telescope type, inch for inch, and is the most
trouble-free telescope that you can buy. Its versatility in
visual, photographic, and CCD work is unmatched. With a
little care, this fine apochromatic refractor will last you a
lifetime. Please enjoy the wonders of the night sky!
Tom
SOME BRIEF SPECIFICATIONS
Aperture ................................................... 130mm (5.1”)
Focal Length ....................................................... 910mm
Focal Ratio .................................................................. f/7
Objective T ype ........air-spaced ED triplet apochromatic
Optical coatings ...................................fully multicoated
Resolving Power (Dawes’ Limit) ......... 0.89 arc seconds
Visual Limiting Magnitude .................................... 13.1
Light Grasp Versus the Eye................................... 345x
Focuser .......... FeatherTouch #FTF3545 rack and pinion
with dual-speed and 11:1 reduction ratio fine focus;
2” and 1.25” compression ring eyepiece holders;
360° rotating camera angle adjuster
Focuser T ravel ........................................4.33” (110mm)
T ube Diameter ................................. 142mm (5.6”) o. d.
Tube Length (lens shade retracted) ...... 28.75” (730mm)
Tube Length (lens shade extended) ....... 34.5” (876mm)
Optical Tube Weight............................18.7 lbs. (8.5 kg)
Back
TMB Optical, P.O. Box 44331, Cleveland, OH 44144 (216) 524-1107
E-mail: TMBoptical@aol.com © 2007 by TMB Optical
TMB Optical
Thomas
Thank you and congratulations on your purchase of
this TMB Optical TMB-130 130mm f/7 ED apochromatic
triplet refractor. Its optical and mechanical quality will give
you many years of observing enjoyment.
TELESCOPE MOUNTS
Y our new TMB-130 is usable with many different types
of telescope mounts. A suitably sturdy altazimuth mount is
a good choice for most purely visual observing. An altazimuth mount is typically light in weight, easy to set up, and
is relatively low-priced. Just be sure that the mount is capable of handling the scope’s weight (which will be well
over 20 pounds after adding mounting rings, diagonal, eyepiece, etc.)
A high quality German equatorial mount would be an
excellent choice for both visual and imaging purposes. The
very stable German-type equatorial mount can be driven
in both right ascension and declination for photography
and CCD imaging, as well as for uninterrupted visual observing. The quality of your images will not only depend
on the optical quality of your telescope, but your local conditions (the seeing and how dark your site is), the tracking
accuracy of your mount, your imaging equipment, and your
guiding and image processing techniques.
TUBE RINGS
No tube mounting rings are supplied with your TMB
refractor. However, well-machined 142mm TMB hinged
split rings are available from your telescope dealer.
FOCUSER
Y our TMB-130 has a dual speed S tarlight Instruments
Feather Touch Model FTF3545 rack-and-pinion focuser.
This ultra-premium focuser has a long travel 3.5” diameter drawtube for non-vignetted astrophotography with
Finder bracket
mounting holes
2”
accessory
adapter
2” accessory
lock knob
(1 of 2)
Coarse focus knob
Features of the Focuser’s Left Side
Focuser rotation
handle (1 of 3)
Screws
connecting
2” adapter
to drawtube
(2 of 3)
Brass
compression
rings
1.25” accessory adapter
TMB-130
M. Back
medium format film cameras and very large chip CCD
cameras. The drawtube ends in a 2” accessory adapter with
a non-marring soft brass compression ring eyepiece holder
that will not damage the barrels of your 2” eyepieces and
accessories. This adapter allows visual use with 2” star
diagonals and eyepieces, plus imaging with 35mm film
cameras and 2” barrel large format CCD cameras.
The 2” accessory adapter is secured to the focuser drawtube by three recessed hex-head screws. Undoing these
allows you to remove the supplied 2” adapter and replace
it with a custom-made Feather Touch adapter for medium
format (Pentax 6 x 7) film photography using A-P photographic accessories. Please contact Starlight Instruments
directly at (847) 985-9595 for any specialized adapters
you may need in this regard.
Focuser
rotation
handle
(1 of 3)
Brass
compression
ring
2” accessory
adapter
SignatureSignature
Signature
SignatureSignature
Focuser
rotation angle
locking ring
Combined drawtube
tension/lock knob
under focuser
Focusing scale
on drawtube
(1 on each side)
2” accessory
lock knob
(1 of 2)
SeriesSeries
Series
SeriesSeries
Coarse
focus
knob
Fine
focus
knob
Features of the Focuser’s Right Side
The supplied 2” to 1.25” accessory adapter is designed
for visual use with 1.25” star diagonals and accessories,
plus imaging with standard format CCD, webcam, and
35mm adapters. This adapter also uses a non-marring soft
brass compression ring to hold your 1.25” star diagonals
and accessories in place. The barrel of this adapter is
threaded to accept standard 2” filters and has a slight inward taper at the top. The taper engages the compression
ring of the 2” adapter to prevent the 1.25” adapter from
slipping out of the focuser, should the 2” adapter’s thumbscrew accidentally loosen during use.
Your Feather Touch focuser has dual-speed focusing.
There are two coarse focusing knobs. The right knob also
has a smaller concentric knob with a 10:1 ratio reduction
gear for microfine focusing. This provides exceptionally
precise image control during high power visual observing
and critical film or CCD imaging. The focus knobs have
ribbed gripping surfaces so they are easy to operate, even
while wearing gloves or mittens in cold weather.
Y our focuser drawtube has a long 110mm (4.33”) travel.
It has two scales (one on either side) that are laser-engraved
in 1mm increments. These let you note individual focuser
positions for easy return to the correct focus when switching between visual use and photography.
Because your Feather Touch focuser is so smooth in
operation and moves so freely, it can only hold a limited
amount of weight (generally about 1 lb.) without drifting
out of focus when the focuser drawtube is not horizontal
and has a significant vertical component. The focuser therefore contains an adjustable-tension internal brake system
to allow astrophotography and visual use with heavy eyepieces without the possibility of focus shift.
The brake consists of a lever arrangement within the
focuser’s pinion block. Adjusting the thumbscrew underneath the pinion block causes the lever to press a friction
pad onto the pinion. This increases the torque needed to
turn the focus knobs. If the thumbscrew is turned all the
way in (only 1 to 1½ turns), the pinion shaft and drawtube
are locked into position at the desired focus for long exposure imaging. Visually, partial tightening of the internal
brake offers a virtually infinite range of braking force to
accommodate various eyepiece and accessory weights.
A built-in camera angle adjuster (focuser rotation system) lets you rotate the focuser a full 360° without losing
focus. This lets you rotate the focuser to line up a camera
in either a landscape or portrait orientation (or any orientation in between). It also lets you put your star diagonal
and eyepiece in the most comfortable observing position
as you move from one area of the sky to another.
Three focuser rotation handles and recessed finger grips
in the locking ring around the front of the focuser body let
you adjust the focuser rotation angle. While holding the
2” accessory adapter of the focuser steady with one hand,
use the rotation handles to turn the locking ring slightly
counterclockwise to unlock the focuser. Rotate the focuser
to the desired new orientation. While again holding the 2”
accessory adapter steady, turn the locking ring back clockwise to lock the focuser in place at the new angle.
Your focuser drawtube glides on three stainless steel
straps that mate with Teflon bearing surfaces to provide
very tight yet extremely smooth motion. This design eliminates the need for grease between the housing and drawtube. A greaseless drawtube prevents the collection of dirt
that may eventually cause problems between these surfaces,
so no routine focuser maintenance is required except for
an occasional wipe down of the drawtube with a soft cloth.
FINDERSCOPE
No finderscope is provided with your TMB-130. However, there are two holes for a finder bracket drilled and
tapped on 1.25” centers at the 10 o’clock position on the
rear of the focuser. These holes will accept any of a number of finderscope mounting rings. Contact your telescope
dealer for an appropriate finder if you do not already have
one that is suitable.
COOL DOWN TIMES
For any optical system to give its best wavefront (sharpest and highest contrast images), the optics must be at or
very near the temperature of the surrounding air . This “cool
down” time needed to reach ambient temperature varies
considerably, as the temperature of the telescope must
change from a typical 72° Fahrenheit indoor temperature
to an outdoor temperature that can range from a high of
over 100° down to 20° below zero or less.
With small doublet refractors, the cool down (or heat
up) time is quick, usually less than 30 minutes. In larger
refractors, or in subfreezing temperatures, it can take a telescope one to two hours to reach its best performance. This
is particularly true with triplet refractors, where the thermal load of the center lens is isolated from the surrounding air by the lenses on either side of it. This slows the
transfer of the center lens heat load to the outside air.
If you’d like to shorten the wait to reach thermal equilibrium in backyard observing, place your telescope in an
unheated garage for a few hours before observing. This
can shorten the cool down process considerably.
Another technique for shortening cool down time in
the field is to retract the dew shield to allow direct exposure of the lens cell and lens to the night air so they reach
thermal equilibrium faster. Refractors show a noticeable
undercorrection during cool down. By comparing a star’s
image on both sides of focus you can determine when the
images are similar and the lens is near optimum correction. At this point, slide the dew shield back out to its fully
extended position. This provides a quicker cool down time,
and will generally still keep the lens from dewing up.
Only on the highest dew point nights will the objective
form dew on the front optical surface. If you live in a high
humidity climate, however, we recommend the regular use
of a dew heater strip.
The best way to avoid dew forming on the lens after
you bring your telescope into the house is to take your
closed telescope carrying case outside with your scope,
where the case can also reach ambient temperature. When
you are finished observing, cap your telescope with its dust
caps and place it into the carrying case. Bring it into the
house and let it slowly warm back up to room temperature,
then remove the dust caps to allow any trace of dew to
evaporate. Once the objective is free from dew, replace
the dust caps and store your scope away.
CLEANING
The best policy is not to let your lens get dirty and/or
dusty in the first place. The use of the dust caps is highly
recommended. However, no amount of preventative measures will stop the objective from eventually collecting dust
and airborne pollutants on the first optical surface.
W e recommend that you do not clean the objective too
often, no matter how frequently the urge to do so may hit
you. A few specks of debris on the lens will not be visible
in your images, as they are not in the focal plane. They
don’t block enough light to measure, let alone be seen.
Depending on how often you use your scope, and the
amount of pollutants in your air, you may have to clean
your scope as often as twice a year, but generally no more
than that – and preferably no more than once a year. If the
front lens surface becomes dusty, smeared, or shows fingerprints or any other surface build-up, and you find it
absolutely necessary to clean the lens, use the following
technique to clean it.
First, gently blow away any surface dust or particles
with a clean air blower (a child’s ear syringe or a
photographer’s camel’s hair brush with attached blower
bulb, for example). The use of canned or compressed air
should be avoided, if possible, as the propellant in the can
may spit out and leave difficult-to-remove deposits on your
lens. Also, the expanding compressed air drops in temperature as it leaves the can. The cold air coming out of
the tiny tube that most compressed air cans use to direct
the air flow has been known to chill a lens to the point of
spalling glass chips off the lens if pointed at the same spot
on the lens too closely for too long.
If you want, or need, to use compressed air to remove
stubborn particles, use a high quality compressed air duster
(the R-134 propellant type). ChemTronics sells a highquality unit. Do not tip or shake the can. Blow any loose
particles off your lens surface using short blasts at an angle
to the glass, without getting too close to the lens surface or
aiming directly at it.
Moisten a ball of USP grade pure cotton with a few
drops of a photographic-quality optical cleaning solution
designed for multicoated camera and binocular lenses. You
can use Formula MC (available from many telescope dealers) or your own mixture of distilled water and a drop or
two of mild soap. A well-worn 100% cotton handkerchief
also works well and Zeiss and Kodak both make suitable
cleaning fluids. Blot the lens surface with the dampened
cotton ball or cloth to pick up any stubborn particles and
to clean the surface. Exchange the cotton ball and/or turn
the cloth frequently so you always have a clean portion of
the cotton ball or cloth in contact with the lens.
Use a very small amount of liquid – not so much that
the fluid could be wicked between the lenses by capillary
action. Do not drip the cleaning fluid directly onto your
lens. Do not, at any stage, apply hard pressure. Using a
fresh piece of cotton or a lint-free white facial tissue, carefully clean the surface of the lens by wiping from the center to the edge in a radial direction. Repeat the process
with denatured alcohol, blowing off any dust that may fall
on the lens as you are cleaning it.
If you want to take the ultimate step in cleaning, a final
rinse with HPLC grade acetone, or any high-grade acetone,
will clean the surface to new condition. You may notice a
few faint streaks on the lens from the dried solvent. They
will not affect performance, but can be removed if desired
with light pressure and a Q-Tip slightly moistened with a
small amount of alcohol or acetone. Finally, a few short
blasts of air from a clean air blower bulb can be used to
remove any remaining dust.
Avoid overcleaning your scope. The multicoatings on
the lens are quite hard and durable. However, frequent
overzealous cleaning can scratch the coatings if all the dust
particles (which are often tiny flecks of windborne rock)
are not removed before you start pushing a damp tissue
around the lens surface. Clean your optics only when absolutely necessary. If you take proper care of your scope,
cleaning should rarely be needed.
COLLIMATION
Your telescope was carefully collimated prior to shipment to your dealer. W ith normal care the optics will keep
that alignment permanently. However , if the telescope takes
a very strong blow in shipping or while transporting it to
your observing site, there is the small possibility that you
may have to recollimate the lens. The lens cell has three
pairs of push-pull collimating screws that will allow you
to collimate it using a metric Allen wrench.
To gain access to the collimation screws, remove the
black trim ring/knife-edge baffle from the front of the dew
shield by unthreading it in a counter-clockwise direction.
Set it aside and push the dew shield back on the optical
tube until the front of the dew shield clears the lens cell
and exposes the collimation screws at the rear of the lens
cell, as shown in the illustration below .
Collimation screws
(1 pair of 3)
Lens cell
Trim ring /knife
edge baffle
removed from
dew shield
Dew shield
fully
retracted
How to
access the
collimation
screws
We recommend either of two collimation methods. In
the first, a “Cheshire” eyepiece (available from T ectron or
your telescope dealer) is inserted directly into the eyepiece
holder (without using a star diagonal). The Cheshire method
can be used indoors or in the field, day or night.
The dust cover is placed over the lens cell to seal the
objective end of the scope and keep light from entering
the optical tube. A bright light source is aimed at the opening in the side of the Cheshire eyepiece. You can use the
light from the sky outdoors during the day. At night or indoors, aim the light of a flashlight directly at the opening
in the side of the Cheshire.
Look through the hole in the end of the Cheshire. You
will see a series of faint circles of reflected light against a
black background. If the circles of light are all concentric,
your scope is in collimation. If the circles of light are not
concentric, adjust the push-pull collimation screws until
you line up the off-center circles to form a single round
circle. The illustration on the next page shows a close-up
of one of the pairs of collimation screws.
The taller screw is the actual collimation screw , while