Askar 71F Flat-Field ED Refractor
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Askar 71F Flat-Field ED RefractorAskar 71F Flat-Field ED RefractorAskar 71F Flat-Field ED Refractor
Askar 71F Flat-Field ED RefractorAskar 71F Flat-Field ED RefractorAskar 71F Flat-Field ED Refractor

Askar 71F Flat-Field ED Refractor

£599.00
  (1 Review)
✓ 2 year warranty

:  

Out of stock due 10-15 working days

About this product

Model:  askar_71f_flat_field
Part Number:  71F

Askar 71F Flat-Field ED Refractor

The Askar 71F features quadruplet (four lenses) air-spaced optics with an ED glass lens that provides a flat-field, 44mm, full-frame imaging circle with minimal chromatic aberration. 

The Native F6.9 Focal Ratio delivers very good image quality for both astrophotography and visual astronomy. 

The flat-field design eliminates the need to calculate back focus distance or buy additional flatteners. Simply attach your camera and focus. 

The sturdy dual-speed 2.4-inch R&P includes a 1:10 micro-focusing and a 360° scale field rotator for precise angle adjustment. 

Askar includes a photographic extension tube with M48*0.75 and M54*0.75 adapters and a built-in 2-inch filter thread for easy shooting connections. It is easy to connect a traditional DSLR or dedicated astronomical camera. 

Askar also includes an 8mm eyepiece (60x magnification), a 20mm eyepiece (25x), and a 1.25-inch 45° erecting prism for visual astronomy. The erecting prism ensures views that are right way up and not inverted. These accessories convert the 71F into a high-quality terrestrial telescope that can also be used for birding and nature observation. 

The convenient handle incorporates a 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 included dovetail plate is a 230mm long standard Vixen-type with slotted 1/4 screw holes as well as 3/8 screw holes for direct tripod attachment.

The telescope weighs only 2.5kg, and its gross weight is 3kg (including the tube rings and dovetail plate). This makes it convenient for travel. 

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

Objective lens diamater

71mm

Focal length

490mm

Focal ratio

f/6.9

Optical design

Quadruplet air-spaced optics with one ED glass lens

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 (dew shield contracted)
430.9mm, including 1.25" adapter (dew shield extended)
415mm, including photographic adapter (dew shield contracted)
473.4mm, including photographic adapter (dew shield extended)

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):  
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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.

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