SDP65SS Optical Tube Assembly at CP+2025 Special Site

Compact Astrograph! High performance approaching that of the VSD series is now more accessible.

The optical system is made up of 4 elements in 4 groups including 1 SD lens and 1 ED lens, so you can easily enjoy unprecedented imaging performance approaching that of the VSD series. The newly designed inner-focus mechanism makes it even easier to use!

Designed for Astro imaging.

The lens is made up of 4 elements including SD glass, high refractive index ED glass, and Lanthanum glass, and the power arrangement of these lenses has been optimized. This has significantly reduced axial chromatic aberration, while successfully suppressing astigmatism to the same level as the flagship VSD series telescopes.

It provides a high level of correction for the distortion of peripheral star images, achieving an extremely flat image surface even without a flattener lens, and creating beautiful star images across the entire field of view of the dia. 44m image circle.

Excellent flatness

IC1805 (The Heart Nebula) and IC1848 (The Soul Nebula)

Optical system: SDP65SS
Camera: ZWO ASI6200MM Pro (35mm full-frame)
Filter: LRGB filter
Exposure time: 100 min. (L: 5 min. x 8 (Gain 0), R/G/B: 5 min. x 4 (Gain 100))

The lens is made up of 4 elements including SD glass, high refractive index ED glass, and Lanthanum glass, and the power arrangement of these lenses has been optimized. This has significantly reduced axial chromatic aberration, while successfully suppressing astigmatism to the same level as the flagship VSD series telescopes.

It provides a high level of correction for the distortion of peripheral star images, achieving an extremely flat image surface even without a flattener lens, and creating beautiful star images across the entire field of view of the dia. 44m image circle.

Abundant peripheral illumination

It is designed to narrow the light flux at the final lens. Vignetting is unlikely to occur regardless of the shape of the camera adapter, etc., so rich peripheral light can be obtained with any shooting system. More than 90% of the light is ensured at the very periphery of a full-frame camera, and a significant reduction in image processing such as peripheral light correction is expected.

Newly designed inner-focus system with fixed eyepiece

Inner-focus mechanism is employed that moves the objective lens unit back and forth using a rack and pinion. It is equipped with a vernier that can read the focus position in 0.1mm increments. Since the eyepiece does not move, the focus is not affected even when heavy camera equipment is attached, and there is no need to retract the eyepiece short after use as with the draw tube type.

Readout for scales (with vernier)

Incorporates a readout for scales serving as a guide for the focusing position, making it possible to read in 0.1mm increments with the vernier.

Compatible with focuser

For more precision focusing, it is compatible with a Dual Speed Focuser (optional) or ZWO EAF (electric focuser).

Lightweight and compact design

It is extremely compact in 413mm long, and even more compact at 359mm when the retractable dewshield is stored, making it easy to carry around.

Supports shooting with a wider field of view! SDP Reducer 0.8x (Optional)

The focal length of the SDP65SS is shortened by approximately 0.8 times, and the F value is reduced from 5.5 to 4.4, ensuring an image circle φ30mm (covering APS-C, and more than 90% light intensity at the very periphery). Even at the very periphery of φ44mm of the full-frame format, 70% light intensity is ensured while minimizing star image distortion.

M45 (The Pleiades)

Optical system: SDP65SS + SDP reducer 0.8x
Camera: ZWO ASI6200MM Pro (35mm full-frame)
Filter: LRGB filter
Exposure time: 100 min. (L:5 min. x 8 (Gain 0), R/G/B: 5 min. x 4 (Gain 100))

Spot diagram comparison with the FL55SS telescope

Even with the FL55SS + Reducer HD for FL55SS kit, which has received high praise for its imaging performance, the peripheral image is somewhat distorted when enlarged to a 100μm scale in the spot diagram. On the other hand, with the SDP65SS, the star image is well-balanced and rounded.

Gallery

IC2177 (The Seagull Nebula)

Optical system: SDP65SS
Camera: ZWO ASI6200MM Pro (35mm full-frame)
Filter: LRGB filter
Exposure time: 120 min. (L:5 min. x 10 (Gain 0), R: 5 min. x 6 (Gain 100), G/B: 5 min. x 4 (Gain 100))

NGC1499 (The California Nebula)

Optical system: SDP65SS + SDP reducer 0.8x
Camera: DSLR camera (35mm full-frame)
Exposure time: 90 min. (L: 5 min. x 18)

NGC2244 (The Rosette Nebula)

Optical system: SDP65SS
Camera: ZWO ASI6200MM Pro (35mm full-frame)
Filter: LRGB filter
Exposure time: 125 min. (L:5 min. x 10 (Gain 0), R/G/B: 5 min. x 5 (Gain 100))