Vixen SD81SII 81mm f/7.7 Super ED Apochromatic Refractor Telescope

Experience the Stars: Clear and Crisp Views

Want unparalleled precision in stargazing? Get the Vixen SD81SII telescope to capture celestial wonders without dealing with annoying aberrations.

Features

• 81mm / 3.2" Apochromatic Refractor: Offers stunning views of celestial objects with superior image quality.
• 625mm Focal Length, f/7.7 Focal Ratio: Ideal balance for both visual observation and astrophotography.
• FPL53 Super Extra-Low Dispersion Glass: Minimizes chromatic aberration for clear, high-contrast images.
• Multicoated Optics: Ensures maximum light transmission for bright, crisp views.
• Versatile Adapter Threads (60mm and 42mm): Compatible with a wide range of accessories and cameras.
• 1.25" Dual-Holder Flip-Mirror Diagonal: Conveniently switch between two eyepieces or an eyepiece and a camera.
• Red Dot Finderscope: Simplifies locating and tracking celestial objects.
• Lightweight and Portable Design: Easy to carry and set up for stargazing on-the-go.
• Robust Focusing Mechanism: Rack-and-pinion system with lock knob for precise focusing.
• Vixen Standard Dovetail Plate: Quick attachment and detachment, compatible with various mounts.

The Vixen SD81SII is for you if…

• You're an Amateur Astronomer: Seeking superior optics to explore the moon, planets, and deep-sky objects with breathtaking precision.
• You're an Astrophotographer: Looking to capture stunning, high-quality images without dealing with chromatic aberrations.
• You Value Portability: Need a lightweight, portable telescope that's easy to set up and transport to various observation sites.
• You Demand Durability: Require a reliable, well-constructed telescope that minimizes maintenance and withstands regular use.
• You Seek User-Friendly Features: Prefer a telescope with an intuitive design, making it easy to use and enjoy the wonders of the night sky.

Unleash the potential of your astronomical pursuits with the Vixen SD81SII 81mm f/7.7 Super ED Apochromatic Refractor Telescope – your gateway to the cosmos. 

Designed for amateur astronomers and photographers alike, this optical marvel lets you capture the moon, planets, and deep-sky objects with breathtaking precision and clarity.

Vixen's standard "photo-visual" SD apochromatic refractor with a handy focal length of 625mm.

Vixen SD apochromatic refractors feature "Super extra-low Dispersion" optical glass in its objective lens. The SD81SII has a ring spacer around the objective lens to make the diffraction pattern of stars visible equally for more refined star images in astrophotography. With the use of an SD reducer HD kit or SD Flattener HD kit, the image circle of 44 mm in diameter is obtained to be used for photography with DSLR cameras with full-frame imaging sensors.

A ring spacer placed around the objective lens refines star images beautifully in astrophotography.

In the previous SD81S model, a set of three tiny tin foils are placed around the objective lens as a spacer between the doublet lens. The end of the tin foils protruding over the objective lens obstruct the incoming light. As a result, the protruding tin foils make the light of diffraction of stars chipped radially. Exchanging the tin foils for the spacer ring makes the diffraction of the stars' light equal. It allows you to create more refined and beautiful star images in your astrophotography.

The SD lens suppresses residual chromatic aberration far below the threshold of visibility.

A lens of refracting telescopes has chromatic aberration which is caused by different wavelength of visible light (colors) focusing at different distances. The Vixen SD lenses, made of FPL53 super extra-low dispersion glass, allow for correcting the chromatic aberration over a wide spectrum of light.

The SD lenses focusvisible rays of light from the C-ray(red), d-ray(yellow), e-ray(green), F-ray(blue) to g-ray(violet) at nearly the very same position. As shown in the diagrams of spherical aberration, it verifies that the chromatic aberration is highly corrected over a wide spectrum of light with the SD lenses.

Especially the g-ray, which affects image contrast, is suppressed excellently. The SD81SII delivers outstandingly sharp images with high contrast for both visual and photographic applications. Moderately bright F7.7 images will satisfy the most demanding visual astronomer or astrophotographer.

A short optical tube in length is handy for not only visual observation but also astrophotography.

The ED81SII optical tube has a moderate short length to enable you to carry and set it up readily. Also, a lightweight optical tube allows you to balance it with fewer counterweights. The ED81S comes equipped with a metal carry handle and the Vixen standard dovetail slide bar M for quick attaching and detaching.
The provided Flip mirror diagonal switches incoming light to allow for using two eyepieces of different magnifications alternately. Also, you can install a camera on the straight side and view an image through an eyepiece on the right-angled side of the flip mirror diagonal.

Full-frame imaging with a DSLR camera.

Using an SD reducer HD kit or an SD Flattener SD kit, which are available optionally, the SD80SII provides an image circle of 44mm, adequate for taking photos with a DSLR camera. (Photo) M8, M20 nebulae taken with Vixen SD81SII with SD reducer HD kit (compound focus 496mm) and Pentax K-1 at ISO1600, 49 minutes exposure.

Optional accessories to expand your pleasure of taking astrophotography.

SD Reducer HD Kit: This kit includes a flattener lens to be combined with a reducer lens for a flat and wide imaging field when you use them with the SD81SII, SD103SII, or SD115SII optical tube. The reducer lens reduces a focal length by 0.7X. 
Direct Wide Photo Adapter 60DX: It is available for Nikon DSLR cameras. It is possible to change the orientation of a camera for a framing of the photographic field.

Elevate Your Stargazing Experience

Invest in the Vixen SD81SII 81mm f/7.7 Super ED Apochromatic Refractor Telescope and elevate your stargazing experience. With its exceptional optical performance, ease of use, and versatile capabilities, this telescope is the perfect choice for those who seek to explore the cosmos with precision and clarity. Join the ranks of satisfied astronomers and astrophotographers who trust Vixen for their celestial observations.