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Askar FRA 500 , 90 mm F5,6 flat field triplet astrograph met 2 ED lenzen  en 2 lenzige corrector - 1

Askar FRA 500 , 90 mm F5,6 flat field triplet astrograph met 2 ED lenzen en 2 lenzige corrector

ASK_500
€2,275.00
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Askar FRA500 It boasts a quintuplet air-spaced APO optical structure, a “three plus two” Petzval lens combination. The 90 mm front lens group consists of three lenses (including two pieces of ED glass) for excellent correction of aberrations. The flatfield corrector is composed of two lenses with an image circle of 55mm, at a focal lenght of 500 mm 

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The Askar FRA500  astrograph 

From the front, the Askar FRA500 has an impressive dew shield decorated with a classic bright-red bezel ring. The total length of FRA500 is 452mm when the dew shield is stretched out and 410mm when contracted back. At the tail end of the astrograph locates a 3.5" massively-built focuser with dual-speed hand knobs (twin knobs for coarse adjustment and one 1:10 fine adjustment knob), which is of great use in real observation or astrophotography.

The focuser can be rotated.

The astrograph wears smooth coating and is evenly finished. The graduation inside of the focuser is quite clear and easily readable. The focuser is tough and solid, and on the left side of it, there is a standard finder base with a silver thumb screw. So the FRA500 can piggyback carry finders, guiders or other potential astronomy accessories also it has  a pair of sought-after tube rings. On the top of the tube rings attached a handle and at the bottom, there is an Askar Losmandy-style dovetail plate.

All is protected in a very well made flightcase,

The Askar FRA500 is 410mm long and weighs about 4kg , so it’s quite convenient for users to carry around or mount on an EQ mount. It’s particularly suitable for astronomy enthusiasts who frequently engage in long-distance trips or out-door astrophotography.

There is a special reducer  for sale, to bring the telescope to a very fast sytem  flatfield F 3.9.!!

The Askar FRA500 give with  a unique optical design and the subsequently high-quality imaging results a loyal companion alongside your journey of astrophotography.

Aperture size:90mm

Focal length:500mm

Focal ratio:f/5.6

Objective lens:Quintuplet air-spaced APO (including two ED glass)

Image circle:55mm

Back focus:158mm(from base of M48×0.75 thread on the conical extender to focal plane)

           85mm(from base of M86×1 thread on the rotator to focal plane)

Total length:452mm(410mm when the dew shield is contracted)

Net weight:4.1kg

Gross weight:5.2kg

Rear-end thread type:M86×1

Conical adapter:M48×0.75 in 3 parts

Package items:an FRA500 OTA, a pair of tube rings, a handle, an Askar Losmandy dovetail plate, a conical  a finderscope holder  a extender, a manual and a flightcase

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Askar FRA 500 , 90 mm F5,6 flat field triplet astrograph met 2 ED lenzen  en 2 lenzige corrector

Askar FRA 500 , 90 mm F5,6 flat field triplet astrograph met 2 ED lenzen en 2 lenzige corrector

Askar FRA500 It boasts a quintuplet air-spaced APO optical structure, a “three plus two” Petzval lens combination. The 90 mm front lens group consists of three lenses (including two pieces of ED glass) for excellent correction of aberrations. The flatfield corrector is composed of two lenses with an image circle of 55mm, at a focal lenght of 500 mm 

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