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2866 USD
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price without VAT: 2330 USD
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Shop online:
● ready for shipping
Shop in Warsaw (qty): 1
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Shop in Chorzow (qty):
● on request
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The Askar 131F Flat-Field 131/983 mm f/7.5 Quadruplet air-spaced APO is a four-element apochromatic astrograph with built-in flat-field correction, designed for astrophotography as well as visual observing. Its quadruplet design eliminates the need for an additional flattener and, after focusing, does not require the fixed working distance typical of external correctors. The telescope provides a 44 mm image circle, making it suitable for use with full-frame cameras.
• four-element air-spaced apochromatic optical system with one ED glass element
• 3+1 optical layout - three elements at the front and one element at the rear
• integrated flat-field correction - no additional flattener required
• 44 mm image circle suitable for full-frame sensors
• no need to maintain the traditional backfocus distance required by external field correctors
• internal baffles to reduce stray light
• retractable dew shield with locking screw
• 3" rack-and-pinion focuser with 1:10 fine adjustment
• 360° rotator with scale and locking screw
• photographic adapters with M54 × 0.75 and M48 × 0.75 threads
• 2" filter mounting option in the M48 × 0.75 adapter
• 1.25"/2" visual adapter for visual observing
• two finder bases near the focuser
• carrying handle mounted on the tube rings
• 300 mm Losmandy-style dovetail plate
• focuser mounting holes prepared for an electric focusing bracket
• compatible with astronomy cameras, DSLR cameras, mirrorless cameras, OAG, filter drawer, focal plane adjuster and M48 extension tubes
• Askar 131F optical tube assembly
• pair of tube rings
• carrying handle
• 300 mm Losmandy-style dovetail plate
• four-piece set of photographic adapters
• manufacturer: Askar
• model: 131F Flat-Field
• telescope type: flat-field apochromatic astrograph
• optical design: quadruplet air-spaced APO
• lens layout: 3 elements at the front and 1 element at the rear
• number of optical elements: 4
• ED glass: one ED element
• aperture: 131 mm
• focal length: 983 mm
• focal ratio: f/7.5
• image circle: 44 mm
• full-frame support: yes
• focuser: 3" dual-speed R&P focuser
• fine adjustment: 1:10
• focuser travel: 30 mm
• rotator: 360° with scale
• rear threads / adapters: M78 × 1 to M54 × 0.75; M54 × 0.75 to M54 × 0.75; M54 × 0.75 to M48 × 0.75
• filter thread: 2" in the M48 × 0.75 adapter
• accessory connection range in imaging mode: 43-73 mm from the base of the M48 × 0.75 thread; 61-91 mm from the base of the M54 × 0.75 thread
• accessory connection range in visual mode: 101-131 mm from the end of the 1.25" eyepiece holder; 111-141 mm from the end of the 2" eyepiece holder
• total length with 1.25" adapter and retracted dew shield: 878 mm
• total length with 1.25" adapter and extended dew shield: 963 mm
• total length with photographic adapter and retracted dew shield: 941 mm
• total length with photographic adapter and extended dew shield: 1026 mm
• dew shield extension length: 85 mm
• outside diameter of the lens cap: 163 mm
• outside diameter of the dew shield: 157 mm
• outside diameter of the tube section behind the dew shield: 125 mm
• dovetail plate length: 300 mm
• dovetail standard: Losmandy-style
• OTA net weight: 7.9 kg
• weight with tube rings and dovetail plate: 9.4 kg
The Askar 131F Flat-Field combines a larger aperture, full-frame field correction, a practical adapter system and a solid focuser, making it suitable as a deep-sky imaging astrograph and a telescope for visual use.
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