TMB Optical Telescopes

More Information  · Supplied Accessories  · Recommended Accessories  · Related Documents  · Images of Some Features Price $3,999.00 Shipping $59.95 Highest Useful Magnification 260x Visual Limiting Magnitude 13.1 Focal Length 910mm Focal Ratio f/7 Resolution 0.89 arc seconds Aperture 5.1" Net Weight 18.7 lbs. Warranty 2 years

This TMB Optical refractor has: • 130mm f/7 air-spaced apochromatic triplet optics using FPL-53 ED glass • collimatable temperature-compensated lens cell • 3.5" Feather Touch rotatable dual-speed rack and pinion focuser • 2" and 1.25" compression ring eyepiece adapters • retractable dew shield, dust covers, and fitted hard case • state-of-the-art optical performance, exceeding even fluorite scopes • sales limited to 100 scopes per year to maintain the value of your investment • normally available from stock – with no multi-year waiting list

    The TMB-130 Signature Series refractor – named a Sky & Telescope Hot product for 2007! – puts exceptionally high optical and mechanical quality in a portable and easy-to-manage 28.75" long package. It is ideal for the serious observer who will accept nothing less than unsurpassed imaging and visual observing performance. The TMB-130 is one of the finest optical instruments, both optically and mechanically, that TMB Optical has ever designed – which means, quite simply, that it is one of the finest optical instruments ever designed for the serious amateur astronomer. Period. The late Thomas M. Back, the designer of the TMB-130, felt that his TMB-130 apochromat refractor had the best price to performance of any apo refractor on the market. We agreed with him when he designed it, and we have seen nothing since then to change our opinion.

    The TMB-130 is exceptional for observing and imaging within the solar system. Its images of subtle low-contrast lunar and planetary details are razor-sharp, with realistic and highly saturated color. Those images are free from chromatic aberration of any type, thanks to the scope’s air-spaced ED triplet optics. The latest antireflection multicoatings and knife-edge internal baffles assure the maximum image contrast possible. Image excellence is limited only by the seeing conditions, not by any aberration or short-coming in the telescope.

    In addition, this 5.1" TMB combines a refractor’s traditional high light transmission and diffraction-free images with a very flat field. The combination makes the scope surprisingly good for deep space observing and imaging, as well as solar system observing. Binary stars and globular star clusters are particularly well-resolved and vivid, with the contrasting colors of binary systems showing nicely. Nebulas and galaxies stand out briskly against a very dark sky background.

Here are some TMB-130 images, taken by Bob McCourt, and used with his kind permission. Bob used a modified Canon 40D DSLR. His TMB-130 was riding on a Celestron CGE mount and guided by a Meade DSI Pro camera on a 66mm refractor. All images were stacks of 5 minute exposures, with the exception of the Comet Holmes picture, which consists of stacked 2 minute exposures. The links below will take you to the full-sized images. The full size images measure between 800 x 502 pixels and 1726 x 1183 pixels in size.

This Telescope’s Optical and Mechanical Systems . . .

• Apochromatic triplet ED refractor optics: 5.1" (130mm) aperture, 910mm focal length, f/7 air-spaced triplet lens using an FPL-53 ED (Extra-low Dispersion) glass element for a flat field and images that are free from spurious color (chromatic aberration). The lens cell is temperature-compensated for stable images during cool-down. The lens cell is also fully collimatable in the field so you can optimize your images for peak performance.

• Multicoated optics: Fully multicoated on all surfaces with the latest antireflection materials for exceptionally high light transmission and excellent contrast. Light transmission is so high that the optics seem to virtually disappear when viewed from head on.

• Retractable dew shield: Slows the formation of dew on the lens to extend your undisturbed observing time. Also improves visual and photographic contrast by shielding the lens from off-axis ambient light (the neighbor’s yard light, moonlight, etc.) For transport, the retractable lens shade keeps the overall length of the optical tube very manageable, at only 28.75" retracted and 34.5" extended. The dew shield has a knife-edge baffle built into its trim ring to improve contrast by blocking off-axis ambient light.

• Feather Touch rack and pinion focuser: The Feather Touch precision-made #3545 focuser is the best refractor focuser available today, period. The fine-pitch brass rack and hardened stainless steel pinion gear are factory-matched and burnished to provide a very smooth engagement between the rack and the pinion. The drawtube glides on three stainless steel straps that mate with Teflon bearing surfaces to provide very tight yet extremely smooth motion. Using this type of design eliminates the need for grease between the drawtube and housing. A greaseless draw tube prevents the attraction of dirt that may eventually cause problems between these surfaces. The drawtube has machined internal baffles, finished in glare-resistant black, to reduce reflections and improve contrast.
      There are two coarse focusing knobs for focusing with either hand. The right knob also has a smaller concentric knob with a 10:1 ratio reduction gear for microfine focusing. Combined with the ultra-low backlash focuser design, this provides exceptionally precise focus control during visual observing or critical imaging. The focus knobs have ribbed gripping surfaces so they are easy to operate, even while wearing gloves or mittens in cold weather.

• Focusing scale: The extra-long 110mm travel 3.5" diameter focuser drawtube has two laser-engraved scales (one on either side of the drawtube) marked in 1mm increments so you can note individual focuser positions for easy return to the correct focus when switching between visual use and photography. A thumbscrew underneath the focuser body lets you lock in your photographic focus, in addition to letting you adjust the focuser’s internal brake.

• Focuser brake: Because the 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 internal to the pinion block. Adjusting the thumbscrew on 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 the drawtube are locked in position for long exposure astrophotography. Visually, partial tightening of the internal brake offers a virtually infinite range of braking force to accommodate various eyepiece and accessory weights.

• Built-in camera angle adjuster: The focuser includes a built-in camera angle adjuster as standard equipment. It is not an optional extra-cost accessory, as it is with some other scopes. A locking ring on the body of the scope lets you rotate the entire focuser a full 360° to line up a camera in either a landscape or portrait orientation (or any orientation in between) without losing your focus. This also allows the positioning of objects for photography and makes the location of guide stars much easier. You can also use it to put a star diagonal and eyepiece into the most comfortable observing position, and temporarily lock the focuser in that position.
      The focuser body is locked in place with the focuser-locking ring that encircles the front of the focuser body. Turning this ring slightly counterclockwise unlocks the entire focuser assembly, allowing it to be rotated in either direction. Once the desired position is reached, the focuser assembly is locked in the new orientation by turning the focuser locking ring back slightly clockwise. The large diameter of the locking ring lets you clamp the focuser firmly at the desired angle without having to resort to excessive force to hold it in place. Three handles and finger grooves on the locking ring provide a good grip in cold or damp weather.

• Eyepiece adapters: The focuser drawtube terminates in a 2" compression ring eyepiece/accessory adapter. A separate 1.25" compression ring eyepiece/star diagonal holder is also supplied that fits into the 2" adapter to let you use 1.25" accessories. The non-marring soft brass compression rings of both the 2" and 1.25" eyepiece holders won’t scratch the barrels of your expensive accessories or star diagonals, as ordinary thumbscrews can.

• Large format astrophotography adapters: While the supplied 2" accessory adapter allows the use of most 2" barrel large format CCD cameras and 35mm photo adapters, some astrophotography enthusiasts prefer to use 92mm diameter Astro-Physics photo accessories. These can be accommodated by removing the 2" accessory adapter attached to the 3.5" focuser drawtube (it is held in place by three recessed hex-head screws) and adding an optional A-P accessory adapter. These are available directly from Starlight Instruments, the manufacturer of the Feather Touch focuser.

• Finderscope mounting point: No finderscope is supplied, but two mounting holes are provided on the upper left side of the focuser body for mounting an optional finderscope, such as the Astronomy Technologies Astro-Tech #ATF illuminated multiple reticle non-magnifying finder.

• Mounting rings: No mounting rings are supplied with the 142mm diameter optical tube. Optional TMB split felt-lined mounting rings (#TMB142R) are available for mounting the scope on a suitable equatorial mount, such as a Celestron CGE, an Orion Atlas GT, or a Losmandy G11.

• Shipping/storage case: The TMB-130 comes standard with a foam-lined aluminum-frame hard case for transportation and general protection purposes. The case weighs 14 pounds and measures 10" x 10.5" x 33". It has four locking latches and a spring-loaded carrying handle that automatically folds down into a recess in the case when not being used.
      TMB Optical is one of the very few manufacturers to provide a case at no charge for protection during shipping and as a storage convenience when the scope is not in use. Unfortunately, FedEx, UPS, and the Postal Service are very good at treating packages roughly. Occasionally, your scope can arrive in perfect condition, but with the walls of the shipping case dented in transit from rough handling, or the aluminum frame sprung, rendering the appearance of the case less than pristine. Damage to the shipping case in such instances is not covered by warranty.

• Two year warranty: As an expression of the confidence TMB Optical has in the quality of their products, the TMB-130 is protected by a two-year limited warranty against flaws in materials and workmanship (shipping case excluded).