Askar FRA300 Pro 60mm f/5 Quintuplet Petzval Flat-Field Astrograph #FRA300

กล้องดูดาว Askar FRA300 Pro 60mm f/5 Quintuplet Petzval Flat-Field Astrograph #FRA300

• Askar FRA300 Quintuplet refractor with 60mm aperture and f/5 focal ratio, ideal for wide-field imaging of the deep sky
• Quintuplet Petzval ED design delivers flat field across 44mm image circle with virtually no chromatic aberration
• Includes rotatable 2.5” dual-speed rack-and-pinion focuser, Vixen-style dovetail, tube rings, and carrying handle
• Length = 303mm, Weight = 3.12kg

The Askar FRA300 compact astrograph incorporates a five-element design to deliver flat fields and sharp, color-free images. With a 60mm triplet objective with an ED element and a two-element corrector, this f/5 scope has a focal length of 300mm and makes an ideal instrument for capturing stunning wide-field images of the deep sky over a 44mm full-frame image circle.

The fast f/5 Petzval design means no additional field flatteners or focal reducers are required which offers flexibility with back focus when incorporating additional accessories in the optical train.

This premium astrograph includes a 2.5” rack-and-pinion dual-speed focuser that’s fully rotatable through 360 degrees to make it easier to frame images. The focuser tube and included adapters allow for direct attachment of cameras with M42, M48, or M54 threads. Note that the limited available back focus, though sufficient for cameras and some imaging accessories, is not sufficient to allow use of this scope with a diagonal and eyepieces for visual use.

The attractive spray-coated optical tube of the FRA300 is complemented with a set of CNC-machined aluminum rings, a 300mm Vixen-style dovetail, and a carrying handle with a slot for a guide scope. The entire tube is just 303mm long and weighs 3.12kg.

For the price, this fast apochromatic telescope offers excellent value and can approach the performance of telescopes that cost three or four times as much. This is especially true when matched with astronomy cameras with smaller 1" and 4/3" sensors. Cameras with larger APS-C and full-frame sensors may, in some cases, reveal slight aberrations at the edge of the field.

Specifications:

• Aperture size：60mm
• Focal length：300mm
• Focal ratio：f/5
• Objective lens: Quintuplet fully air-spaced Petzval APO (including one ED element)
• Image circle：44mm full-frame
• Maximum accessory connection (with the focuser fully retreated)：
  • Imaging mode:
    • 71mm (from the base of M42×0.75 male thread)
    • 67mm (from the base of M48×0.75 male thread)
    • 71mm (from the base of M54×1male thread)
• Total length：303mm
• Net weight：2.26kg
• Gross weight：3.12kg
• Rear-end thread：M48x0.75 male thread
• Main tube diameter = 82mm; Dewshield diameter = 91.3mm

What's in the Box