TS-Optics Photon 305 f/4 OTA This PHOTON Newtonian combines a 305 mm (12") aperture with a 1220 mm focal length at f/4. Its parabolic primary mirror and fast optical geometry support deep-sky imaging and visual astronomy.
Manufacturer model: TS-Optics Photon 305 f/4 OTA · Specifications checked against manufacturer data on 2026-11-04
This PHOTON Newtonian combines a 305 mm (12") aperture with a 1220 mm focal length at f/4. Its parabolic primary mirror and fast optical geometry support deep-sky imaging and visual astronomy.
Optics and illumination
The manufacturer specifies 94% enhanced mirror reflectivity with a protective quartz layer. Secondary-mirror size and illuminated-field figures are specific to this aperture; the table distinguishes fully illuminated field from partial illumination where TS publishes both.
Focusing and tube
The metal tube is fitted with a 2" Monorail focuser with 1/10 dual speed, adapter to 1.25" and compression ring. Use the published dimensions and assembled-weight configuration when selecting a mount; cameras and other added equipment contribute further load.
Imaging configuration
A suitable coma corrector is optional for wide-field imaging. Native focuser backfocus is available mechanical travel/spacing, not automatically the sensor-spacing requirement of a chosen corrector. Keep primary and secondary collimation aligned for the installed camera train.
Additional specifications
Aperture ratio
f/4
100 illuminated field
23 mm - ideal for APS-C format sensors with suitable coma corrector
90 illuminated field
35 mm - thus also suited for larger sensors (flats helpful)
Limiting magnitude visual
16.5 mag
Tube dimensions
Length 1170 mm, diameter 356 mm
Manufacturer listed equipment
TS 12 f/4 Newtonian Tube rings (dovetail is optional) 2" extension tube 35 mm for visual observing Dust cover for the front opening Primary fan with battery holder 8x50 finder with quick releaseNote: The telescope is delivered without dovetail bar; a suitable bar can be found under "Recommended accessories".
63053
Data sheet
Aperture
305 mm (12")
Focal length
1220 mm
Focuser
2" Monorail focuser with 1/10 dual speed, adapter to 1.25" and compression ring
Manufacturer part number
TPM12F4
Model
TS-Optics Photon 305 f/4 OTA
Primary mirror
Parabolic primary mirror with 94% reflection and protective quartz layer
Resolution
0.39 arc seconds
Secondary mirror
100 mm minor axis with 94% enhanced reflection and protective quartz layer
Support surface on the bottom of the tube rings
Flat support surface with an M6 thread
Support surface on the top of the tube rings
Flat support surface with a 1/4? internal thread (tripod socket)
Tube material
Steel
Tube weight
21 kg with tube rings and finder
Specific References
MPN
TPM12F4
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TS-Optics Photon 305 f/4 OTA This PHOTON Newtonian combines a 305 mm (12") aperture with a 1220 mm focal length at f/4. Its parabolic primary mirror and fast optical geometry support deep-sky imaging and visual astronomy.
Manufacturer model: TS-Optics Photon 305 f/4 OTA · Specifications checked against manufacturer data on 2026-11-04
