APM CNC-LW II 180/1260 Refractor OTA

Description

Shave 140mm off the focal length of a comparable 175mm apo and the difference shows up immediately in the eyepiece: wider framing, faster imaging, and an f/7 ratio built for speed rather than pure magnification. The APM CNC-LW II 180/1260 resolves down to 0.64 arcseconds, sharp enough for severe double star separation that slower ratios can’t match.

Like every OTA in this line, the tube ships without a mount or tripod, and at 17.5kg it needs an equatorial setup rated for at least 35kg once you add a camera and imaging train. The payoff for that weight is a wide-field APO refractor built to gather light fast across a bigger sensor, cutting exposure times on faint deep-sky targets that a slower scope would take twice as long to capture.

Key Features of APM CNC-LW II 180/1260 Refractor OTA

The same 3-element air-spaced Super ED triplet formula APM uses across this line delivers 99.6% transmission per surface, tuned here for a faster f/7 output.

• Faster f/7 focal ratio cuts exposure time on faint deep-sky targets compared to slower APO designs
• Zero secondary obstruction keeps contrast high across the full field, with no diffraction spikes from support vanes
• 0.64-arcsecond resolving power holds up even on demanding double star pairs
• Starlight Instruments Feathertouch dual-speed focuser locks in critical focus without slipping under a heavy imaging train
• 60mm image circle covers medium-format sensors edge to edge without vignetting
• Retractable dew shield protects the front element through long unattended imaging runs
• Losmandy D-style dovetail with CNC tube rings keeps the tube balanced as accessories are added
• Magnification tops out at 360x, with a practical low end of 26x for wide framing

What Makes the APM CNC-LW II 180/1260 Different

Compared to the longer 1400mm focal length in this series, the 180/1260’s shorter tube trades a bit of pure magnification for a meaningfully wider field and faster f-ratio, which matters more than raw aperture for anyone imaging large nebulae or galaxy fields rather than tight planetary detail. The heavy-duty flight case included with the OTA reflects that this tube is built to travel to darker sites, not just sit on a permanent pier.

Applications & Use Cases

Suited to professional observatory-grade wide-field deep-sky astrophotography, this refractor also handles severe double star separation and demanding lunar and planetary tracking across large-format sensors.

• Imagers prioritizing wide nebula and galaxy fields over tight planetary close-ups
• Observers who need a mount rated for at least 35kg and want the fastest ratio in this aperture class

APM Warranty & Support

The CNC-LW II 180/1260 carries a 2-Year Factory Warranty covering manufacturing defects on the optical tube and focuser assembly, handled directly through APM’s support channel.