The fast SCT, reinvented.
8 inches. f/2.8. Carry-on weight.
The Observable Space FSCT8 is the first native f/2.8 Schmidt-Cassegrain ever built in an 8-inch form factor. A 42 mm image circle, fused silica quartz mirrors, and a 267 mm carbon-fibre OTA under 9 kg — designed from the optical axis out for astrophotographers who demand observatory results without the observatory.
Every clear night is too short. The FSCT8 makes sure you get the most out of every hour of it.
f/2.8 native. The SCT form factor finally fast.
A conventional 8-inch SCT runs at f/10. The FSCT8 runs at f/2.8 natively — no reducer stacks, no optical compromises. That is a 13-fold increase in photon-gathering speed. A four-hour integration target becomes roughly 20 minutes of effective exposure. For imagers working under Australian skies with limited clear nights, this is the most impactful single step up possible.
mm fully illuminated image circle. Sharp stars across the entire field at under 6.2 μm RMS — covering APS-C and most medium-format sensors with no vignetting.
Quartz mirrors. Focus doesn’t move.
Primary (210 mm) and secondary (114 mm) mirrors are both fused silica quartz — the same glass used in research-grade observatories. Near-zero thermal expansion means the focus point does not drift as temperature drops. Your collimation is still correct at 3 am.
267 mm OTA. Fits where full-size SCTs don’t.
The carbon-fibre upper cage is rigid, thermally stable, and keeps total OTA length at just 267 mm. That is shorter than many refractors. It mounts on mid-range equatorial platforms and travels as carry-on — without sacrificing the optical performance of a full 8-inch system.
Flat field. Corner to corner. No caveats.
The 88 mm broadband AR-coated corrector lens flattens the focal plane and holds sub-6.2 μm RMS optical performance across the full 42 mm image circle — from dead-centre to the corner of a full APS-C sensor.
Your full imaging train. No extensions required.
A 100 mm back focus from the mounting surface accommodates camera, filter wheel, electronic focuser, and off-axis guider without extension tubes. The 2.75 μm per arcsecond image scale is matched to modern small-pixel CMOS sensors — making the most of every pixel in the frame.
Purpose-built for imaging. Not retrofitted for it.
Observable Space — the PlaneWave and OurSky collaboration — built the FSCT8 as an imaging instrument from the ground up. Mirror material, corrector geometry, tube construction, back focus distance: every decision serves the astrophotographer. This is not a visual SCT with a reducer bolted on. It is a dedicated astrograph that fits in a carry-on bag.
8-inch aperture. Mid-range mount. Dark-sky remote site. All viable.
At under 9 kg and just 267 mm OTA length, the FSCT8 is mountable on equatorial platforms that a conventional 8-inch SCT with reducer stack would overload. It travels as carry-on, sets up in minutes, and puts professional-grade optical performance within reach of any dark-sky site — no permanent observatory required.
NGC 6992. The Eastern Veil Nebula.
Supernova remnant in Cygnus. Delicate filamentary emission structure that demands long exposures from slower systems resolves here in a fraction of the integration time — f/2.8 working exactly as intended.
M97. The Owl Nebula.
Planetary nebula in Ursa Major, approximately 2,600 light years distant. Extended shell structure and the characteristic owl-eye cavities resolved in a single night — a target that a slow system would need multiple sessions to match.
More signal per hour. Every clear night finally worth the effort.
Native f/2.8 focal ratio — the first fast SCT in an 8-inch system, designed for wide-field deep-sky imaging from the optical axis out
42 mm fully illuminated image circle with optical performance under 6.2 μm RMS across the full field — sharp stars edge to edge
Fused silica (optical-grade quartz) primary (210 mm) and secondary (114 mm) mirrors with enhanced aluminium coatings for temperature stability
Carbon-fibre upper cage construction — 267 mm OTA, under 9 kg total weight for use on mid-range to high-end imaging mounts
88 mm broadband AR-coated corrector lens delivers a flat focal plane and 2.75 μm per arcsecond image scale suited to modern CMOS sensors
100 mm back focus from mounting surface — accommodates cameras, filter wheels, and electronic focusers in a standard imaging train
4°+ field of view with a 42 mm sensor — ideal for large emission nebulae, galaxy groups, and all-sky survey programmes
An Observable Space instrument — the merger of PlaneWave precision optics engineering and OurSky imaging systems expertise, purpose-built for the astrophotographer
