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Ultra-compact 80mm f/11.3 Mak-Cassegrain OTA. Weighing only 1.1kg and 245mm total tube length, fits into a business bag and carriable anywhere. The excellent optics yields very crisp images up to highest power for planetary observations. Useful features like a versatile dovetail plate, a lightweight dot-sight finder and a folding dustcover are all inclusive. Ideal for beginners, yet nice as a casual sub-scope for advanced astronomers and a quality telephoto lens for birders.
<Development Concept>
"Compact and lightweight as fitting into a business bag, carriable anywhere, easy to use, suitable for both astronomical and terrestrial observations and photography, not too small aperture, excellent optical quality, yet very reasonably priced - a telescope with all those factors is eagerly demanded".... To satisfy this grasping requirement, the best "answer" should be a small Mak-Cassegrain. Several kinds of 90mm models are already available, but the tube size is still large and the weight is over 2kg, too large and heavy to fit into a business bag. Besides, the f-ratio of those models is too slow to get low-enough powers suitable for deep sky observations. Considering this halfway situation, Kasai produced this compact scope with the help of our partner factory that has a long experience of manufacturing small Maksutov optics. Just the right optical specs as 80mm f/11.3, only 1.1kg featherweight tube ... and much more special features are integrated in this cute scope by utilizing Kasai's plenty of knowledge through our long experience in dealing with Maksutov telescopes since 1993.
The optics of PICO-8 basically follows a simple Gregory-type Maksutov Cassegrain design, yet optimizing the radius of the corrector plate to achieve both faster f-ratio as f/11.3 and excellent imaging performance as keeping practical sharpness up to highest magnification range like 120x - 160x. Of course no chromatic aberration is detectable. The secondary obstruction is comparatively small (34%) for this kind of compact Cassegrains, contributing higher definition, exerting high performance in observing faint figures on planets.
<Tube & Finder>
The main tube is made of metal with glossy pale cream finish. The front and the tail parts are made of durable ABS resins to keep the lightweight feature. The folding dustcover (detachable) in front of the corrector plate is standard. The 150mm long dovetail plate (metal) on bottom is Vixen-compatible to fits various mass-market mountings. Four 1/4"-20 threaded holes on the dovetail plate fit photo/video tripods directly. Comes with a simple and very lightweight (only 40g) red dot sightfinder, detachable from the base when transported. This finder base (metal) is compatible with Vixen, GSO, SYNTA and many other brands'.
<Focuser & Eyepiece Adapter>
Moving primary mirror focusing mechanism is adopted. Though the design is simple, annoying mirror shift is kept in very small level, assuring a stress-free focusing even in high power observations. The eyepiece adapter (metal) is for 1.25" size with brass compression ring, and M42/T2 male threads to accept various T2-format accessories. Of course T-ring can fit directly without any other adapter or ring, accepting a camera body for prime-focus photography. (Notice: The camera rotary angle adjustment should be done with 3 small setscrews around T-ring.)
<Collimation (Optical Axis)>
The primary mirror collimation screws are equipped on the tail part (around the eyepiece adapter), permitting fine adjustment of the optical axis. Still, as each unit is carefully tested and pecisely collimated by Kasai before shipment, and the scope itself is durable enough to keep well collimated condition under normal usage, generally there will be no need for the users dare to make re-collimation works.
<General Aptitude>
Combining ultra compactness and high optical performance, PICO-8 is suitable for various uses: casual observation on the balcony, star & terrestrial watching while travelling, observing & photographying wild birds, daily solar observations with a solar filter, mounting onto another telescope as a guidescope .... this "Small Almighty" can satisfy various users' various requirements.
Clear Aperture 80mm
Focal Length 900mm
Focal Ratio F11.3
Central Obstruction 27.2mm
Obstruction Rate in Diameter 34%
Obstruction Rate in Area 11.6%
Tube Diameter 94mm
Tube Length 200mm (245mm incl. Eyepiece Adapter)
Weight 1,060g (1,100g incl. Finder)
Focsuing Mechanism Moving Primary Mirror Focusing Mechanism
Other Features *Primary Mirror Collimation Function
*Vixen-Compatible Dovetail Plate with 1/4-20 threads x 4
*Dovetail Base for Finder Bracket
Standard Accessories Red Dot Sight Finder (X-Y Direction Adjustable / Illumination Adjustable)
Folding Dustcover
<Astronomical Set>
+ 1.25" Diagonal Prism
+ FMC PL-25mm
+ FMC PL-6mm
<Astro/Terrestrial Set>
+ 1.25" 90º Erecting Prism
+ FMC PL-25mm
+ FMC PL-9mm
<Terrestrial Set>
+ 1.25" 45º Erecting Prism
+ FMC PL-25mm
+ FMC PL-12mm
Kasai Trading Co., Ltd.
5-19-33, Kami-Meguro, Meguro-Ku, Tokyo 153-0051, JAPAN