Altair ASCENT 102mm F11ED Refractor Geared Focuser
The ASCENT 102mm F11 ED Doublet refractor is optimised for visual observation and imaging of solar system objects. An evolution of the well respected "Classic" Starwave 102 F11 Achromat, now with ED optics and better mechanics!
The result is improved colour correction and contrast. It a geared focuser replaces the original Crayford style focuser allowing for heavier accessories, and the tube can be broken down offering 270mm of back-focus for bino-viewing, or your own custom modifications for solar viewing with a PST module.
The Starwave ASCENT 102mm F11 ED is particularly effective for visual observation of planets, the moon and double stars and it copes with turbulent air (seeing) extremely well due to it's long focal length. Focusing is very "relaxed" at F11 and contrast is superb.
It is also a very capable solar imaging telescope (with the appropriate filter) for white light (with the Altair Solar Wedge), and of course Hydrogen Alpha. It is easy to focus due to the extended depth of field and gives extremely sharp images. The long focal ratio minimises eyepiece aberrations, resulting an extremely flat field of view. Bino-viewing is easy - just detach the bino-viewer extension and most binos will come to focus without a Barlow lens.
Summary:
- ED optics with geared focuser!
- The machined and powder-coated aluminium tube can be broken down into two parts for easier transport, bino-viewing or solar PST Mods which require a shorter tube.
- Proper Dual Speed Geared focuser with micro focusing (essential for fine detail).
- The 2" push-fit adapter has 3x thumbscrews and a brass compression ring. Diagonal barrels aren't marred, eyepieces and binoviewers or heavy Ha solar filters are firmly held and aligned.
- Flat field and superbly high contrast with easy focusing make this an ideal visual telescope.
What you get:
- Starwave 102mm F11 ED Doublet Objective, with full multi-coatings on all surfaces in a collimatable lens cell with QC serial number. Guaranteed to arrive in perfect collimation.
- 2.5" Dual Speed Geared focuser with 1:10 ratio fine-focusing knob.
- Rear 2" push-fit adapter with 3x thumbscrews and inner compression ring.
- 2"-1.25" Push-Fit Adapter with non-marring brass compression ring.
- Optional 9x50 finder with metal body and front focusing lens. Metal mounting stalk is able to attach direct to the optical tube (screws provided) or with the Altair Universal Quick Release Finder Bracket (code: UNIFBR-QRB). High quality 23mm wide field eyepiece with laser etched, independently focusing reticule. (Not the usual fare on finder scopes).
- Front push-fit metal dust cap, rear plastic plug style dust cap.
- Genuine CNC machined tube rings, fully adjustable for balance and rotation.
- Metal dovetail plate so you can use the scope with just about any telescope mount including iOptron, Skywatcher.
- Metal dew-shield 200mm length, 121mm diameter, retractable, can be unscrewed for lens cleaning.
- The optical tube is 100cm length and weighs about 4.6kg.
- The removable Bino-viewer section is 120mm length therefore total tube length is 88cm when removed.
- Back-focus is 150mm from rear end of focuser to image plane. (270mm back-focus to the image plane if Bino-viewer tube is removed).
The advantages of the ED version. When compared to the previous "Classic" Achromat the V3 offers truer colour rendition thanks to the ED optics. The Starwave 102 ED delivers a sharp "contrasty" image with better colour correction than the previous achromatic version, and star images are just as "tight". The 102mm aperture gathers about 63% more light than an 80mm refractor and the brighter image shows noticeably more detail. With a higher power eyepiece or Barlow lens, this telescope will show details within the planetary disc of Jupiter, the Great Red Spot, cloud bands of different sizes and textures, as well as the four largest Galilean moons and their shadows cast on Jupiter. The contrast is very good enabling you to see a Jovian moon against the brightly lit background of Jupiter. Saturn's rings and Cassini division are easy to see at higher magnifications and cloud bands are visible on Saturn as well as the polar caps. Mars shows surface features and polar caps easily. Thousands of craters are visible on the moon - enough for a lifetime of observation. Customers often reported the previous "Classic" Achromatic version of this telescope outperformed reflectors of 6 and 8" on planets and the moon in contrast and subtle detail. In summary, the ED version improves on the Achromat version both optically and mechanically, with a modest price increase.
The convenience of a refractor. This is the perfect scope to take out and just observe with. It cools down fast thanks to the aluminium tube and long focal length doublet objective design. Unlike reflectors, the optics do not require frequent collimation (alignment) before use, so the product is virtually maintenance free aside from the usual yearly cleaning of the lens.
Finder scopes and auto-guiding: You can attach the optional finder scope to easily locate astronomical objects. There are two ways to attach it. Firstly by means of the two screws provided and secondly by means of the Universal Quick Release Bracket (see options when ordering). The Deluxe Altair 60mm Deluxe RACI Finder Scope is also compatible, and attaches to the focuser using the Universal Quick Release Finder Bracket.
Magnification: The magnification of a telescope is determined by dividing the telescope focal length in mm by the eyepiece focal length in mm. For example, the Starwave ASCENT 102ED has a 1122mm focal length, which, when used with the Altair Ultraflat 24mm eyepiece yields 47x magnification. (E.g. 1122mm divided by 24mm = 47x magnification). If you use a Barlow lens (such as the Altair 2x Flat Field Barlow) just multiply the magnification by 2x. In this case, the result is 94x.
Here's a table with Altair Ultraflat and Planetary eyepiece focal lengths, and the resulting magnifications with the Starwave 102EDF11:
| Eyepiece focal length: | 6mm | 7mm | 10mm | 12.5mm | 15mm | 18mm | 24mm | 30mm |
| Magnification: | 187x | 160x | 112x | 90x | 75x | 62x | 47x | 37.4x |
Finding objects in the telescope. Using a low power eyepiece at around 25x you can quite easily spot a bright or large object by sighting along the telescope, however fainter and smaller objects would benefit from the optional "finder scope" accessory.
For imaging with the Altair Hypercam or GPCAM cameras, you can attach a camera or filter wheel by means of the rear 2" "push-fit" visual back (which has 3x thumbscrews for extra tight grip and zero flex).
Specifications
Starwave ASCENT 102ED F11 full technical specifications:
- Optical Design: Fully Multicoated ED Doublet lens in collimatable cell
- Aperture (mm): 102 mm (4")
- Focal Length: 1122 mm
- Focal Ratio: F11 (F8.8 with 0.8x reducer)
- Optional Finder-scope: 9x50 focusing objective (206.6mm focal length). Finder-scope Eyepiece: 23mm focal length with laser etched reticule, independent focusing for eyeglass users.
- Highest Useful Magnification: 200 x
- Limiting Stellar Magnitude: 13
- Resolution (Dawes): 1.14 arc seconds
- Light Gathering Power (Compared to human eye): 212 x approx. (7mm pupil)
- Optical Tube Length: 100cm / I metre
- Optical Tube Weight: 4.6kg Approx.