ASKAR FRA400C F/5.6 APO REFRACTOR

Name: ASKAR FRA400C F/5.6 APO REFRACTOR
Brand: Testar Australia
Price: 1699.00 AUD
Availability: OutOfStock

$1,699.00AUD

Askar

Apochromatic Petzval quintuplet

3.18 kg

The Askar FRA 400C f/5.6 is a professional apochromatic Petzval quintuplet with an aperture of 72mm and a corrected field of 44mm in diameter.

The lenses are assembled in two groups: an air-spaced triplet on the front and a correcting doublet towards the focus. The objective lens includes two Extra Low Dispersion glass for a superb chromatic correction.

Differently from standard ED refractors, the Askar 400C features a Petzval design that does not require to set the sensor to a specific distance to the last lens. That leaves the freedom to use any filter wheel, any off-axis guider or accessory without any worry to calculate the correct distance from the flattener.

With a large 44mm fully corrected image circle and a focal ratio of f/5.6, this is the perfect astrograph for the advanced astrophotographer.

All the lenses are fully multi-coated and the tube is internally blackened to reduce reflections and absorb stray light.

Specifications

Optical design	Apochromatic Quintuplet dual ED air-spaced
Objective diameter	72 mm
Focal length	400
Focal ratio	f/5.6
Image Circle	44mm
Aperture Blade	17 pieces
Aperture range	f/5.6-f/22
Resolving power	1.66 arc second
Closest Focus Distance	5m
Stellar limiting magnitude	11.3
Max. magnification	144 x
Light gathering power	106 times the human eye
Mount attachment	Vixen style bar
Focuser	Manual focus
Front filter diameter	M82
Camera connection	M72, M54, M48
Backfocus	50-60 mm (55mm recommended)
Tube weight	3.18 kg (including handle and dovetail bar)
Tube length	370 mm
Dew shield diameter	108 mm
SKU	AS-FRA400C