ASKAR FRA500 refractor

Askar presents a new refractor, currently the best-selling of the quintuplet series, the FRA500 90mm; It is an instrument suitable for astrophotography.

Thanks to the quintuplet spaced in the air, it provides a flattened field up to 44mm diagonally without the addition of further flatteners/reducers.

This new and enormous APO guarantees chromatic correction at the highest levels thanks to a precise and obsessive construction by Sharpstar; the image is not affected by any chromatic aberration and remains very clear and well contrasted.

The FRA500 refractor is ASKAR's flagship 90mm aperture, you won't find a product with the same features at a lower price!

Technical features

Improved mechanics

The very precise mechanics guarantee universal application in every astronomical field and extreme satisfaction in use.

In addition to the improvement of the optics, the FRA500 also offers improved mechanics that leave nothing to chance, in this way the performance of the apochromat can be fully exploited even in the astrophotographic field.

FPL53 air-spaced apochromatic quintuplet with multi-coating on each optical surface, this makes the optical quality very good and no chromatic aberration even at maximum magnification.

The objective of this apochromat is composed of a triplet spaced in the air also composed of elements supplied by the famous Ohara (Made in Japan), in fact the central element is composed of Ohara SuperAPO-FPL53 ED glass.

ASKAR quality control

One reason why ASKAR refractors are very famous and of very high quality is their quality control, in fact interferometric and optical tests are conducted on all the apochromats of the house, making the work carried out by these instruments impeccable.

ASKAR 3.5" Rack&Pinion focuser with integrated rotator

This refractor uses a brand new 3.5" ASKAR focuser, with integrated rotator that can be rotated 360° to always keep the camera in the correct position, thanks to the Rack&Pinion system, the focuser can withstand very heavy loads without any torsion problems.

The 1:10 gear mechanism offers precise focusing and is ideal for astrophotography.

Technical features

• Opening size: 90mm
• Focal length: 500mm
• Focal ratio: f/5.6
• Lens: Air-spaced quintuple APO (including two ED glasses)
• Image circle: 55mm
• Back focus: 158 mm (from the base of the M48×0.75 thread on the conical extender to the focal plane) 85 mm (from the base of the M86×1 thread on the rotator to the focal plane)
• Total length: 452 mm (410 mm when the anti-condensation protection is contracted)
• Net weight: 4.1kg Gross weight: 5.2kg
• Rear Thread Type: M86×1
• Conical adapter: M48×0.75
• Package items: FRA500 OTA, a pair of tube rings, a handle, an Askar Losmandy dovetail plate, a conical extension, a manual