This TeleVue Imaging System refractor optical tube has:
• 102mm f/8.6 ED apochromatic optical system
• 2.4" rack and pinion focuser with 2" visual accessory adapter
• factory-installed Focusmate 6:1 ratio fine focus system
• short tube design for easier imaging and 1x visual use with bino-viewers
• retractable dew shield
• state-of-the-art visual and imaging capabilities
• 5-year warranty The new TeleVue TV-102iis sets very high optical and mechanical quality standards in a moderately small and highly portable apochromatic refractor for the serious observer and astrophotographer.
This 4" 102mm aperture scope uses an ED (Extra-low Dispersion) element in its air-spaced doublet optics. The ED lens element gives the TeleVue TV-102iis diffraction-limited apochromatic (spurious color-free) performance across the entire visual spectrum at a surprisingly reasonable price for a scope of this TeleVue’s quality. In addition to exceptional visual performance, both inside the solar system and beyond, the TV-102iis has been optimized for deep space imaging, even with CCD cameras having large 35mm format detector chips. Every optical and mechanical element has been optimized to work as a single integrated unit, with new features to make imaging easier and more flexible.
For visual use, the scope’s 880mm focal length is long enough, using a 1.25" TeleVue 3.5mm Nagler eyepiece, to provide a maximum 251x for high magnification observations of the Moon, planets, and binary stars; yet it will also produce a very wide 3° field at 16x, using a 2" TeleVue 55mm Plössl eyepiece, for wide field observing.
Its image quality and easy set-up will make it a scope you will use often. Manufacturing advances in lens finishing, including interferometric monitoring of all surfaces, and TeleVue’s stringent made-in-the-USA telescope assembly and quality control, insure uniformly excellent results with every telescope.
Whether you are interested in visual astronomical rich-field or planetary observing, or serious deep space imaging, just put in an optional star diagonal and eyepiece or attach a camera and the TeleVue TV-102iis will satisfy your observing desires right out of its case.
This Telescope’s Optical and Mechanical Systems . . . - ED apochromatic refractor optics: 4" (102mm) aperture, 880mm focal length, f/8.6 apochromatic air-spaced doublet ED optical system. An ED (Extra-low Dispersion) glass element provides images that are free from spurious color and other optical aberrations.
- Multicoated optics: Fully coated on all air-to-glass surfaces with multiple layers of antireflection materials for high light transmission and good contrast.
- Short tube photo/visual design: The physically short tube of this TV-102iis (5" shorter than the standard TV-102) allows you to reach focus with a binocular viewer without having to use a Barlow lens to transfer the image back through the binocular viewer to the eyepieces. This provides 1x binocular viewer magnification with the 102iis (rather than the 1.6x or 2x you get with a conventional scope and a Barlowed bino-viewer). The result is lower power and a wider field of view for more dramatic views when you are scanning star clouds and the larger nebulas with your binocular viewer.
For use with a standard star diagonal instead of a binocular viewer, a 5" long extension tube with a 2" compression ring eyepiece holder is provided to extend the length of the scope to reach focus with a diagonal.
In addition, for the astrophotographer, the physically short length of the TV-102iis provides substantial back focus for long CCD camera/filter wheel accessory trains. The short tube provides the imager with nearly 4" of back focus between the scope’s focuser drawtube and the optional (but necessary) 0.8x reducer/flattener needed for photography. An Imaging System threaded adapter is provided for use with optional imaging accessories.
- Dual-speed rack and pinion focuser: The newly-designed focuser has a non-vignetting internally-tapered drawtube with a 3" entrance aperture and a 2.4" exit aperture. This tapered design prevents any restriction of the converging light cone during astrophotography. The drawtube terminates in an end ring that has a tilt capability to correct for any residual focal plane tilt. This is particularly important with the more stringent focus requirements of CCD cameras. The end ring also accepts a “position stop" for an optional digital micrometer that allows repeatable focus measurements with a 0.0001" accuracy (#TVIK124).
The new focuser’s draw tube also permits quick change from visual observing to astrophotography using the separate supplied 2" visual and imaging adapters mentioned above. The focuser allows full camera rotation without focus change, and without the need to buy a separate camera angle adjuster as some other scopes require. To maintain squareness to the optical axis while changing camera orientation, the draw tube has four lock knobs that tighten against a taper on the supplied imaging adapter and 2" visual accessory holder.
The imaging adapter is threaded to accept TeleVue’s new Imaging System accessories – including large diameter extension tubes, optical accessories, and camera and CCD attachments, all with mating threads. The separate indexed 2" visual accessory adapter has a 2" non-marring brass clamp ring with two lock knobs to hold a 2" star diagonal or other visual accessories firmly in place.
- Fine focus system: The focuser is equipped with a normally-optional Focusmate 6:1 reduction ratio fine focus system on the right focus knob. While the left focus knob still provides TeleVue’s standard focusing speed, the Focusmate on the right knob provides extremely sensitive 6:1 ratio fine focusing for imaging. Focus changes are measurable with an optional Digital Micrometer Kit (#TVIK124) to better than 1/10,000" for precisely repeatable focusing. Both the standard focus and the Focusmate use large knurled focus knobs that are easy to operate, even while wearing gloves or mittens in cold weather.
An optional Focusmate Driver (#TVFMRHD) permits pushbutton electronic motor control of the focusing process. The Focusmate Driver has directional pushbuttons and adjustable speed. A tap on a pushbutton permits vibration-free focusing in steps as small as approximately 0.0005". The Focusmate Driver can be remotely computer controlled with software under development.
- Optional photographic accessories: Optional photo accessories include the following: a Digital Indicator Kit (#TVIK124) for digital readout of the focuser position for repeatable focus points; a Focusmate Driver (#TVFMRHD) electronic vari-speed motor control for the Focusmate fine focus mechanism; extension tubes of various lengths to bring various CCD and 35mm cameras to focus; an adapter to connect the SBIG STL11000 CCD camera (#13STL); an adapter to connect a standard 35mm camera using a T-Ring (#13TRA); an adapter (#13CAW) to connect a Canon EOS or digital SLR using a wide mouth Canon T-Ring; and a 0.8x focal reducer (#1362) required for all prime focus imaging.
- Sliding captive 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 to a manageable 25.5" (without visual extension tube) when it is retracted.
- Mounting rings: No mounting rings are supplied for the 101mm diameter optical tube. The optional TeleVue #MRS4 dual 4" mounting ring set is designed specifically for installing the TV-102iis on a wide variety of equatorial mounts and mounting adapters.
- Finderscope mounting point: No finderscope is supplied. However, dovetail accessory mounting slots for a finderscope and other accessories (such as a piggyback camera mount) are provided on the optional TeleVue #MRS4 dual mounting ring set.
- Carrying case: A custom foam-fitted locking hard shell case is standard.
|
Printer friendly version
Email page link to a friend
Do you have a question about this product?
Terestrial Photography
