ASKAR FRA500 90mm f/5,6 Quintuplet Flatfield APO Astrograph

This telescope is inspected, measured and adjusted if necessary. The eyepiece output is stopped. On request from your telescope, you will receive a meaningful quality certificate (test protocol with star test, Ronchi, adjustment, with individual serial number)! Please specify when ordering!

Examples of our test protocols: Test records
How we adjust: About us

We will send these telescopes free of charge in Germany.

 

ASKAR FRA 500 90 mm f/5.6 Quintuplet Astrograph

ASKAR is the new line of selected telescopes for astrophotography. With these telescopes a high attention is paid to the optical, but also mechanical quality. FRA stands for refractor telescopes with integrated corrector element for a flat and corrected image field. The FRA series is mainly used for astrophotography.

The ASKAR FRA500 is a 5-element apo according to Petzval with 500 mm focal length, f/5.6 and 90 mm aperture. In the lens there are 2 ED glasses for a good correction of chromatic aberration. The apo is corrected for cameras up to full-frame.

The dew shield also provides good protection against stray light and is retractable. The large focuser holds even heavy cameras and allows clean focusing due to dual speed. The focuser offers a range of connections for all common astro threads. Also included is an adapter to M48x0.75, which is ideal for all cameras with 55 mm working distance. This adapter also has a possibility to screw in 2" filters.
 

Focusing the camera in the FRA500 apo

The corrector of the apo is permanently installed in the tube. As soon as you have focused the camera, you are also automatically at the correct distance. The laborious search for adapters in the appropriate thickness is no longer necessary.
 

A photo specialist, but also suitable for observation:

The ASKAR FRA400 is designed for astrophotography. However, due to the comfortable working distance, 2" star diagonals can also be connected. This turns the astrograph into a very nice spotting scope and telescope for astronomical observation and also landscape observation. We will be happy to advise you on the suitable adapter.
 

Increase of the speed to f/3.9

The focal ratio of f/5.6 is already relatively fast. But often one wishes for even faster optics. With the optional FRA400Red you can increase the speed from f/5.6 to f/3.9, thus halving the exposure time. The focal length is shortened to 351 mm.

 

Aperture:	90 mm
Focal length:	500 mm
Focal ratio:	f/5.6
Telescope type:	5-element quintuplet apo with 3-element ED lens
Transport length:	410 mm
Weight:	4.1 kg
Connection camera side:	M68x1 external, M54x0.75 male, M52x0.75 female and M48x0.75 male
Filter thread:	2" filter thread (M48x0.75) is integrated in the camera adapter

In the box:
♦ Apo in gift box
♦ CNC tube rings
♦ Losmandy style dovetail bar
♦ Handle
♦ Photo adapter
♦ Finder shoe (mounted)
♦ Inspection list