The Sky Rover 80 GPS is the portable imaging refractor in the GPS lineup — the one you grab when setup time matters. Eighty millimeters of Super ED triplet glass, 480mm at f/6, integrated Camera Angle Adjuster (CAA), and a package light enough to ride a star tracker or travel mount without complaint. It won't gather light like the 102 or 130, but it cools down in minutes, sets up fast, and starts collecting data while larger scopes are still reaching thermal equilibrium. For the imager who values time-to-first-frame and portability, that trade-off is worth making every clear night. But like all fast triplet refractors, the 80 GPS has inherent field curvature. On-axis, the performance is exceptional. At the edges of an APS-C or full-frame sensor, stellar images soften in a gentle, predictable curve — a physics limitation that becomes obvious the moment you examine a wide-field star field. The SR80GPSFF 1× field flattener is the solution.
The flattener threads directly onto the 80 GPS's integrated CAA using the standard M63×1 connection. It maintains the native 480mm focal length and f/6 ratio — speed, working distance, and exposure time all stay unchanged. What transforms is the focal plane itself. The curved surface becomes flat, matching the flat silicon of your camera sensor. Stars that were tight at center now stay tight and round all the way to the corners. For an 80mm f/6 triplet built for imaging, adding the matched flattener is the final piece — the hardware that completes a portable, ready-to-shoot imaging system.
Flattener, Not Reducer
This is a 1× flattener — it preserves the native focal length and focal ratio of the 80 GPS. You maintain the full 480mm f/6, unchanged. The field of view, exposure times, and image scale all remain the same as the uncorrected scope — you gain what matters: perfectly flat, corrected stars across the entire sensor from center to corners.
Direct CAA Threading
The 80 GPS's integrated CAA features M63×1 female threads. The SR80GPSFF threads directly onto those threads — no adapters, no spacers, just a clean one-piece connection between scope and flattener. This integrated design gives you the mechanical simplicity and optical stability you need for precise imaging work.
Camera Connection
The camera side of the flattener connects to your imaging equipment via standard 48mm T-threads. DSLR and mirrorless cameras connect via a T-ring for your specific camera mount (sold separately). Dedicated CMOS and CCD astronomy cameras typically have 48mm T-threads built in and connect directly without a T-ring.
What's Included
- Sky Rover SR80GPSFF 1× field flattener for 80 GPS
Features
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1× field flattener — no focal reduction. Maintains the 80 GPS's native 480mm f/6. Corrects field curvature for flat, sharp stars across the sensor without changing focal length, speed, or working distance.
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Dedicated design for the Sky Rover 80 GPS triplet. Matched to the 80 GPS's optical prescription and integrated CAA geometry. Purpose-designed for this scope's specific field curvature profile — not a one-size-fits-all accessory.
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Direct M63×1 threading onto CAA. The flattener threads directly onto the 80 GPS's integrated Camera Angle Adjuster. No intermediate adapters — just a solid mechanical connection that maintains optical alignment and stability.
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Portable imaging, corrected. The 80 GPS's advantage is speed — setup speed, cool-down speed, and f/6 photographic speed. The flattener preserves all of that while adding flat-field performance across APS-C and full-frame sensors. You don't give up what makes the 80 GPS convenient.
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Standard camera-side threading. DSLR and mirrorless bodies connect via a T-ring (sold separately); dedicated CMOS/CCD astronomy cameras attach directly — 48mm T-threads are standard on most.
Frequently Asked Questions
Do I need this flattener for visual observing?
No. Field curvature only affects imaging — your eye naturally accommodates the curved focal plane during visual observation. The flattener is specifically for camera work.
How does this flattener differ from Sky Rover's GPA flatteners?
The GPS flatteners thread directly onto the integrated CAA's M63 output, giving you a dedicated, mechanically optimized system. GPA flatteners use different connection threads. Each Sky Rover model has a matched flattener designed for its specific optical and mechanical design.
Will this fit the 70 GPS or other Sky Rover models?
No. The SR80GPSFF is designed specifically for the 80 GPS's 480mm focal length, M63×1 CAA threading, and optical prescription. The 70 GPS uses M54×0.75 threads and has its own flattener. Each model has its own matched accessory.
What cameras does this work with?
DSLR and mirrorless cameras connect via a T-ring for your specific camera mount (sold separately). Dedicated CMOS and CCD astronomy cameras typically have 48mm T-threads built in and connect directly without a T-ring. The flattener works equally well with APS-C and full-frame sensors.
What's the back focus distance?
It has the industry standard 55mm of back focus. The critical measurement is the distance from the flattener's rear threads to the focal plane — ensure adequate spacing for your camera's back-focus design.
Final Thoughts
The 80 GPS is the scope you take when you want to image tonight, not next weekend. It sets up fast, cools down fast, rides a lighter mount, and at f/6 it collects data efficiently. Adding the SR80GPSFF flattener completes the imaging chain — you get the triplet's sharpness, the integrated CAA's precision, and now a flat focal plane matched to your sensor. That's a corrected, portable imaging system you can have shooting in minutes. For the imager who makes the most of every clear night, that's what the 80 GPS was designed to be.
