The ultimate astrograph, now within your reach.

Committed to a 6-Element / 6-Group Design

Developing the SJH-75UF involved many iterations of optical design. While more elements can push performance higher, they also increase design and assembly complexity, elevate cost, and potentially reduce light transmission and the Strehl ratio.

Balancing chromatic aberration, spherical aberration and field curvature at the highest level — while optimizing design, assembly and cost — SIGHTRON JAPAN's definitive answer is this 6-element / 6-group configuration. The spot diameter is 0.67 μm at the center and remains 1.31 μm even at a 22 mm image height.

A Highly Flexible Imaging System

Supports a wide range of accessories — commercial motorized focusers such as the ZWO EAF, off-axis guiders, filter drawers and more. This flexibility for building a complete imaging system is one of the SJH-75UF's key strengths.

Not just for imaging — a telescope for visual observation.

The SJH-75UF supports eyepiece use as well. With a Strehl ratio reaching 99.2%, it delivers pin-sharp, needle-point star images. Lunar craters, planetary belts, and the fine details of nebulae and star clusters all reveal themselves with striking clarity.

Multiple internal baffles, a long dew shield, and special low-reflection anodizing on select lens spacers and baffle rings combine to suppress stray light and deliver outstanding contrast. The full ULR coating across every lens surface keeps transmission loss to a minimum — faint targets stay bright and subtle gradations are preserved naturally.

The 50.8 mm sleeve and 31.7 mm adapter are included as standard. You can enjoy visual observation with your own eyepieces from day one.

CMOS, DSLR, and Visual — All in One

The SJH-75UF comes standard with an M48 thread and 50.8 mm / 31.7 mm sleeve connections. As shown above, camera adapters, filter adapters, filter drawers and off-axis guiders can be combined flexibly.

From astronomical CMOS cameras to DSLR imaging and visual observation with eyepieces — configure the system to suit your needs.

* Accessories shown in the diagram (camera adapters, extension tubes, filter drawers, etc.) are sold separately.

M54 Filter Adapter(release planned)

An adapter that connects the camera with the larger M54 thread instead of M48. This further improves usability when shooting with full-frame cameras. Supports M52 filters.

Suppression of Stray Light

Select lens spacers and baffle rings inside the tube utilize a special low-reflection anodizing that suppresses stray reflection more effectively than standard matte anodizing. By eliminating off-axis ghosting, flare and halation caused by stray light bouncing inside the tube, it reveals subtle detail in faint nebulae and improves contrast on dimmer stars.

Quality of internal finish — invisible on any spec sheet — is what allows the optics to fully express their performance.

ULR Coating Designed for the SJH-75UF

Every lens surface of the SJH-75UF receives a ULR (Ultra Low Reflection) coating designed specifically for this telescope. Optimized for the glass type, curvature and spectral characteristics of each element, this ultra-low-reflection coating dramatically reduces the light lost at every air-glass interface — so faint nebulae and subtle color gradients reach the field at their full original brightness and contrast.

Suppressing surface reflection also makes ghosting and flare around bright stars far less visible. The coating draws out everything the optical design has to give.

Exceptional Rigidity and Micro-Precision Focusing for Heavy Equipment

A high-rigidity rack-and-pinion focuser incorporating a linear guide rail. Even with a heavy full-frame CMOS camera and accessories attached, both the tactile feel of focusing and the payload holding force are maintained. The dual-speed mechanism enables coarse and fine motion for precise focus control.

From the feel of the rotator and the focuser's lock-down to the precision of the drawtube travel — every unit is adjusted and verified one by one.

Everything you need for imaging — in the box.

The SJH-75UF ships with the accessories you need in the field. Tube rings, top plate, dovetail bar, finder shoe — all the essentials sold separately by most manufacturers are included.

Mount it on an equatorial mount the day it arrives, and add a finder or guide scope smoothly. No guesswork about what else to buy before you can start — experience the SJH-75UF's optical performance straight away.

* A separate camera adapter is required when attaching a DSLR/mirrorless camera.

* Equatorial mount, camera, and motorized focuser are sold separately.

MADE IN JAPAN — Hand-Finished, One Unit at a Time

From optical assembly tolerances and focuser torque adjustment to rotator function checks — every item is verified in a strict final inspection before each unit ships.

Each product comes with a 5-year warranty so you can keep using it with confidence. As a domestic manufacturer in Japan, we maintain full repair and maintenance support.

Optics & Performance

Mechanics & Accessories

A Guide for Back-Focus Calculations

Dimensions of the rotator, focuser and drawtube section. Use them when planning back-focus for CMOS cameras, filter drawers, and other accessories.