Askar 71F Flat-Field APO Refractor
  Zoom
Askar 71F Flat-Field APO RefractorAskar 71F Flat-Field APO RefractorAskar 71F Flat-Field APO Refractor
Askar 71F Flat-Field APO RefractorAskar 71F Flat-Field APO Refractor

Askar 71F Flat-Field APO Refractor

£599.00
  (1 Review)
✓ 2 year warranty

:  

5x in stock shipped 1-2 working days

About this product

Model:  askar_71f_flat_field
Part Number:  71F

Askar 71F Flat-Field APO Refractor

The new Askat 71F is an Apochromatic Optical Tube with an aperture of 71mm, a focal length of 490mm, and a native focal ratio of F6.9.

The Askar 71F adopts a quadruplet air-spaced APO lens design, including one piece of ED glass, which can effectively reduce chromatic aberration. The Askar 71F supports 44mm full-frame imaging with great surrounding star points.

The Native F6.9 Focal Ratio delivers very good image quality photographically and visually. The Four Element design ensures you do not need an additional Field Flattener.

The Askar 71F is a self-flattened design that removes the need for users to calculate the back focus and buy additional flatteners. After attaching the imaging accessories, users can directly use it for shooting after the OTA is in focus. This further reduces the cost and improves the pleasure of shooting.

With practicality and versatility in mind, the Askar 71F's weight and size ensure it is portable, making it easy to carry and use. The Askar 71F OTA weighs only 2.5kg, and the gross weight is 3kg (including the tube rings and dovetail plate).

The Askar 71F is versatile in its use, allowing for both visual observation and astrophotography. For users' convenience, Askar has also included three observation accessories standard for the 71F: an 8mm eyepiece, a 20mm eyepiece, and a 1.25-inch 45° erecting prism which converts the 71F into a high-quality Terrestrial Telescope that can be used for Birding and Nature Observing.

The 8mm eyepiece has a magnification of 60x, and the 20mm eyepiece has a magnification of 25x. The Askar 71F can be used with different eyepieces depending on the target, and both eyepieces are ideal for viewing birds and landscapes.

Both eyepieces have a 1.25-inch barrel and a rubberised top for a soft and comfortable user experience.

The 1.25-inch 45° erecting prism provides correct left-to-right and down-to-up image views, making it easy to observe without seeing images reversed up, down, left, and right.

The Askar 71F also includes a photographic extension tube, which includes M48*0.75&M54*0.75 adapters, and a built-in 2-inch filter thread for easy shooting connections. No matter whether connecting a traditional DSLR camera or a dedicated astronomical camera, it is very convenient to use. 

The mechanical design of the Askar 71F itself adheres to Askar's consistent philosophy of high quality and great value.

The dew shield of the Askar 71F is a retractable design, further shortening the overall length and increasing portability. The entire lens tube of the Askar 71F is crafted using high-quality CNC machining. The inside surface of the dew shield is covered with matt paint to reduce stray light reflections effectively. The overall blue and white colour scheme gives the telescope a premium finish.

The Handle Bar includes a standard Finderscope Slot for mounting a Finder/Guidescope.

In addition, there are two finder bases on both sides of the focuser, which eliminates the need for disassembling when changing the position of the finder scope and provides additional mounting positions for other astronomical accessories.

The Askar 71F is equipped with a dual-speed R&P 2.4-inch rigid focuser with a 1:10 fine adjustment and a 360° scale field rotator at the rear end for precise angle adjustment.

The Askar 71F's dovetail plate is a 230mm long standard Vixen dovetail plate with slotted 1/4 screw holes as well as 3/8 screw holes for direct tripod attachment.

The Askar 71F is an affordable and high-quality versatile self-flattened OTA.

Askar 71F Connection Diagram

Locking Screw Position Diagram

What's in the box

  • 1x 71F OTA
  • 1x Pair of tube rings
  • 1x Handle
  • 1x Askar 230mm Vixen dovetail plate
  • 1x Set of photographic adapters
  • 1x 1.25" 45° erecting prism
  • 1x 8mm eyepiece
  • 1x 20mm eyepiece

Specifications

Aperture size

71mm

Focal length

490mm

Focal ratio

f/6.9

Objective lens

Quadruplet air-spaced APO(including one ED glass)

Image circle

44mm

Maximum accessory connection (with the focuser fully retreated)


Imaging mode:
82.5mm (from the base of M48×0.75 male thread)
100.5mm(from the base of M54×0.75 male thread)

Observing mode:
117mm(from the end of 1.25" eyepiece holder)
127mm(from the end of 2" eyepiece holder)

Total length

372.5mm(including 1.25" adapter as dew shield contracted)
430.9mm(including 1.25" adapter as dew shield fully stretched)
415mm(including the photographic adapter as dew shield contracted)
473.4mm(including the photographic adapter as dew shield fully stretched)

Net weight

2.5kg

Gross weight(Including tube ring&dovetail plate)

3.0kg

Rear-end thread type:

M64×0.75-M54×0.75
M54×0.75-M54×0.75
M54×0.75-M48×0.75 (with M48×0.75 filter thread)

Standard package items

A 71F OTA, a pair of tube rings, a handle, a Vixen 230mm dovetail plate,

a set of photographic adapters, a 1.25" 45° erecting prism, an 8mm eyepiece, a 20mm eyepiece

Customer reviews

Average Rating (1 Review):  
Write a Review and share your opinions!

Rating (max 5):  
Excellent Little Scope
05 May 2024  | 

This is a great little scope. Like my other Askar telescopes the 71F is a high quality instrument, the deep blue accents making a welcome change to the red, gold, and green offerings that seem to have become so popular. The fit and finish is first class, and once again Askar appear to have put a lot of thought into the design of both the telescope and the accessories that come with it.

I purchased the 71F to use as a high quality spotting scope as well as for astronomical use, and indeed Askar are promoting the terrestrial capabilities of this scope both in their promotional material, and by including an erect image diagonal and a couple of eyepieces in the package. As far as I know this is the only Askar scope that has this.

This is a handsome looking scope and includes such luxuries as a retracting dew shield, twin finder mounting shoes, a carry handle that can also hold additional accessories, a sensible length 230mm vixen style dovetail bar, CNC machined tube rings, and a rotating duel speed 2.4" focuser.

The included eyepieces are 8mm and 20mm plossls which seem to be of good quality if a little restrictive in their apparent field of view. The erecting diagonal is a bit of a let down in that it is made of plastic - very un-askar-like - but it seems to do the job adequately.

A camera adaptor is also provided. It screws into the focuser in place of the eyepiece holder and terminates in a 48mm thread onto which you can attach a camera T-ring, or the barrel of a dedicated astro camera. The 48mm threaded ring unscrews to reveal a larger 54mm thread, and the facility for mounting a single filter if required. This arrangement is pretty standard for Askar scopes. Back spacing is not an issue, if you are in focus you are good to go.

There is no carrying case provided. For larger scopes this would not be so much of a problem, but small scopes are more likely to be transported around, so a compact padded soft carry case would have nicely completed the package.

Now to the optics, the heart of any telescope. This is a four element flat field instrument that follows the same layout as in the more illustrious PHQ series, comprising is a triplet up front with a single field flattening element further back, the significant difference being that in the 71F there is only one ED element (of unspecified type) rather than two. Having four lenses certainly adds the the weight of the system, and the OTA with its accessories weighs 3kg as compared to 2kg for Skywatcher's 72ED.

So how does the 71F perform? In a word. excellent. In several words, very impressive indeed. Using a 2" 40mm focal length wide angle eyepiece, details were sharp pretty much to the extremities, any minor aberrations probably due to my 25 year old eyepiece rather than the telescope. Attaching a full frame DSLR and taking a series of short exposures in the region around Polaris showed nice round stars right across the frame and into the extreme corners. This is indeed a flat field telescope doing exactly what it claims to do.

Askar didn't quite get it all right though. The small screw that locks the focuser in position is not attached when the scope arrives, but is in a little bag packed away with the instructions and quality control certificate. When I tried to attach it to the underside of the focuser I found that I couldn't because the dovetail plate was in the way. Sliding the tube backwards in the rings cured this, but resulted in the dew shield not being able to retract fully, and with a heavy DSLR attached the balance point was off the rear end of the dovetail plate. Raising blocks under the tube rings would cure this, but to be honest the focuser works so well without the little locking bolt in place that I just removed it.

Next point, the carry handle cannot be used as a carry handle. It it too short, at least for my stubby male hands, and there is not enough room between it and the tube to fit your fingers underneath it. More raising blocks required, perhaps. To be honest though, the 71F is so good in every other way that I can forgive it these minor misdemeanours.

This is a lovely little scope, well equipped, and very good value for money. An absolute winner in my book, and I can recommend it.

FAQ

Please fill in the form below to ask a question.

*
*
*
*
Please add the two numbers