Askar 91F Flat Field Refractor
Want Another Take? Here's Another Option You'll Love
Looking for another no-fuss scope with speedier light gathering capabilities and support for larger imaging equipment? Take a look at the Askar FRA500 APO Refractor! This 90 mm scope is on par with the Askar 91F in terms of aperture, though can help you shave off some imaging time thanks to its faster focal ratio. For instance, a 5 minute exposure with the f/5.6 FRA500 is equivalent in brightness to a ~7 minute exposure with the f/6.7 91F. That’s 1.4x as fast! Additionally, the FRA500 offers expanded gear compatibility thanks to its massive 55 mm image circle. This means you can expect edge-to-edge coverage across medium-format sensors. Even with today’s largest cameras, the Askar FRA500 has you covered. Be sure to explore more of what the Askar FRA500 has to offer!
A Highly Versatile, Powerful Scope from Askar!
Looking for a large, versatile refractor that packs a punch? Askar has just the solution! This Askar 91F is well equipped for both visual astronomy and astrophotography, making it a must have tool for any astronomy enthusiast. Additionally, this scope is excellent for use during daylight hours, either as a spotting scope or for everyday terrestrial photography. The sizable 91 mm aperture delivers bright views and outstanding clarity within your eyepiece—that’s 64% more light gathering power than the Askar 71F! However you choose to utilize this multifaceted scope, you’re set up for success!
As a quadruplet refractor, four internal lenses correct the incoming light to a high degree of precision for stunning detail within your eyepiece and camera sensor. One of these lens elements is extra-low dispersion (ED) glass, a substrate specially engineered for reducing chromatic aberration. These four lenses are air-spaced and arranged within a 3+1 configuration for peak performance. An inherent flat field spans the 44 mm image circle for sharp stars across some of today’s largest sensors, while this Petzval design means there’s no need to fumble with backspacing calculations! As long as your camera can reach focus, the entire field of view will be in focus as well. Askar includes a number of accessories to help get you started: a photographic adapter set, two visual adapters, an erect prism diagonal, multiple eyepieces, a pair of finderbases, and a Vixen-style dovetail plate. Weighing in at just under 10 lbs. fully assembled, the Askar 91F is the perfect companion for any adventure!
Suitable for Any Occasion!
Designed for astrophotography, visual astronomy, and terrestrial viewing and photography, this Askar 91F Flat-Field Refractor is your all-in-one solution! The four internal lenses ensure peak color correction within your astroimages, while the inherent flat field provides pinpoint stars from corner to corner. For those who are in pursuit of awe-inspiring visual sessions, enjoy crisp, sharp views of the full disk of the Moon with the included 8 mm eyepiece, and be stunned by the beautiful glow of the Orion Nebula with the included 20 mm eyepiece. Askar also includes a 1.25” erect diagonal within the box for your viewing comfort! These included visual accessories are highly beneficial for terrestrial viewing as well, offering brilliant, upright sights of wildlife and surrounding landscapes at multiple magnifications. Equipped with a photographic adapter set, adjoining your dedicated astrocamera, mirrorless camera, or DSLR is a breeze. A choice scope for a wide range of applications, the Askar 91F refractor is ideal for every type of explorer!
Feature-Rich and Built to Perform
Multi-use in design, delivering impressive performance, and equipped with everything you need to get started right out of the box, the Askar 91F Flat-Field Refractor is a highly valuable tool for any adventure. Read on as we take a closer look at the key aspects of this Askar scope, highlighting the variety of celestial objects to discover, the supplied adaptability, its focusing system, and what comes standard within this package!
Discover Our Night Sky in Stunning Clarity
With 609 mm in focal length and a large 91 mm aperture, a wealth of celestial objects are ready for observing. Capture vibrant detail on the Orion and Running Man nebulae, fill the frame with the Pleiades Open Star Cluster, and point your scope at the Milky Way core for beautiful images of the Lagoon Nebula. When used visually, the included 20 mm eyepiece offers 30x magnification, a rate ideal for viewing the core of the Andromeda Galaxy, the Hyades Open Star Cluster, and the Hercules Globular Cluster. Or, tack on the included 8 mm eyepiece for a closer look at 76x magnification! This optical scale is perfect for up-close views of the Dumbbell Nebula, the Whirlpool Galaxy, and one of the most popular supernova remnants, the Crab Nebula. For even closer views, tack on a user-supplied Barlow lens for planetary observations as well!
Multiple Adapters Included
Within this package you’ll find a photographic adapter set along with a pair of visual adapters to help get you started. This photographic adapter set houses three different threaded connections: M64×1-M54×0.75, M54×0.75-M54×0.75, and M54×0.75-M48×0.75 (includes M48 filter threads). Whether you plan on attaching your dedicated astrophotography camera, your mirrorless camera, or your DSLR, Askar helps you do so with ease! For those eager to view the wonders of the night sky with their own eyes, the 1.25”/2” visual adapter enables use with just about any eyepiece and star diagonal on the market today.
A Rock-Solid 3" Rack & Pinion Focuser
Boasting a dual-speed Rack & Pinion focuser, finding precise focus is a walk in the park. First find rough focus with the coarse adjustment knob, then narrow in the details with the 1:10 fine adjustment knob. This rigid 3” focuser provides a sturdy mounting point for your imaging train, and can be easily adapted for electronic focusers upon arrival. Thanks to Askar, achieve sharp, pinpoint focus in a snap!
What's Included in the Box?
Starting you off right, Askar has loaded this package with a host of included accessories. As mentioned above, the photographic adapter set ensures seamless integration with your camera, while the 1.25/2” visual back offers use with just about any eyepiece and star diagonal. Furthermore, two eyepieces come included: a 20 mm eyepiece and an 8 mm eyepiece for various viewing opportunities. The 1.25” erect prism diagonal that comes standard with this scope provides a correct left-to-right and up-and-down image orientation, making it easy to maneuver across the night sky and terrestrial scenery. The set of tube rings hold your telescope snug, while the 230 mm Vixen-style dovetail plate is contained with a wide range of equatorial mounts. A retractable dew shield, two finderbases, a built-in 360° rotator, and a dual-use handle bar are also included with this Askar 91F!
Astronomy Hub: Your one-stop-shop for Astrophotography Knowledge!
Our Gear Experts have compiled a wealth of information to help expand your astrophotography knowledge! Below you’ll find links to articles, videos and "how-to" guides. Just one more reason that our Astronomy Hub is a one-stop-shop for all your astronomy and astrophotography needs!
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