Tal 250k Telescope
The Tal 250k Telescope is an excellent instrument based on a novel optical design by Klevtsov. The versatile TAL-250K is the ideal instrument for the advanced amateur astronomer who desires high resolution and excellent light-gathering power (limiting visual magnitude 14) in a highly portable telescope.
The TAL-250K provides an aperture of 250mm and focal length of 2130mm in a very compact tube length of only 450mm. Klevtsov's revolutionary catadioptric design employs a sub-aperture meniscus correcting lens (like the familiar Maksutov) combined with a Mangin mirror-lens secondary.
Its fast focal ratio of f/8.5, flat field, and excellent correction of coma, spherical aberration, and astigmatism (14 micron star images at a distance of 10mm from the optical axis!) make the TAL-250K a superb instrument for astrophotography, far surpassing conventional Schmidt-Cassegrain and Ritchey-Chretien systems.
Every optical component must pass stringent tests.Interferograms on three axes of each optical set are retained by the factory's quality control department.
The telescope is supplied with an 8x50mm finder with a 7 degree field of view, an equatorial mount with motor drive in Right Ascension and manual slow-motion in Declination, two eyepieces of 25mm and 10mm focal length, and a 2x Barlow lens.
At the customer's request, the mounting can be supplied either on a rigid metal pedestal or a hardwood tripod. A fitted wood carrying case is also included.
To comfortably observe objects near the zenith, a diagonal mirror which diverts the light path by 90 degrees is also supplied, as well as an adaptor for 35mm SLR cameras.
All surfaces of the refractive elements have anti-reflection multi-coatings for maximum light throughput. The TAL-250K is a remarkbly compact, easy-to-use instrument that will meet the requirements of the most demanding amateur astronomer.
Tal 250k Telescope Standard Specification
- Aperture, 250mm
- Focal length, 2130mm
- Focal ratio1:8.5
- Resolving power 0.5
- Limiting visual magnitude 14
- Magnification, min 80x (f=25mm)
- Magnification, max 400x (f=10mm)
- Optical scheme Klevtsov
- Angular visual field, max 33' (f=25mm)
- Angular visual field, min 13' (f=10mm)
- Central obstruction area, 12.5%
- Length of tube / with focuser,450/590 mm
- Latitude range of mounting 0...70°
- Focuser 2"/1.25"
- Magnification of the finderscope 8x
- Angular field of finderscope 7°
- Voltage of the supplying mains,220 (110) ±10%
- Current frequency, Hz 50 (60)
- Output voltage of the supply unit, 12V
- Weight of the tube,15.7kg
- Weight of the telescope, 48kg
- Weight of the telescope packed, 70kg
Return From Tal 250k Telescope To Tal Telescopes Main Page Telescopes Home Page