Sky-Watcher Black Diamond Photo 150 on EQ-AL55i Pro Reflector Telescope with Tripod

The Sky-Watcher Black Diamond Photo 150 on EQ-AL55i Pro Reflector Telescope features a powerful 150mm Newtonian aperture with diffraction-limited optics, providing all the light-gathering power required for both visual use and high-end astrophotography. Newtonian reflectors are among the most cost-effective designs on the market, offering much larger apertures than equivalently priced refractors. This large aperture is essential for resolving faint, extended objects like distant nebulae and galaxies, while the 750mm focal length provides the magnification necessary to reveal the fine details of lunar craters and planetary surfaces.

To ensure professional-level precision, the 150/750 Photo Reflector is equipped with a high-quality Crayford dual-speed focuser, featuring a 10:1 reduction adjustment knob for fine-tuning your focus with absolute accuracy. The optical system utilizes an aspheric, parabolic primary mirror to eliminate spherical aberration, while extra-thin secondary mirror spider supports minimize diffraction spikes on bright stars to maximize contrast. For immediate observation, the telescope includes a 3-element 28mm LET eyepiece, providing a comfortable 20mm of eye relief and a 56° apparent field of view.

Product Features in Detail

Precision Dual-Speed Focusing

The Crayford dual-speed focuser is a standout feature for photographers. While the main knob moves the tube quickly into the general focus range, the 10:1 micro-focuser allows you to make tiny, incremental adjustments to achieve the critical focus needed for sharp star images on a camera sensor.

Diffraction-Limited Aspheric Mirror

Sky-Watcher uses a parabolic (aspheric) primary mirror rather than a cheaper spherical one. This ensures that all incoming light rays converge at exactly the same focal point, eliminating the "blurring" effect of spherical aberration and providing the highest possible resolution.

Minimized Secondary Obstruction

The secondary mirror is held by extra-thin spider vanes. By reducing the surface area of these supports, the telescope minimizes light scattering, which increases the overall contrast of the image and produces cleaner, more aesthetic stars.

Excellent Thermal Management

The thin secondary mirror design allows the optics to reach ambient temperature quickly. This reduces "tube currents"—heat waves inside the telescope that can distort the view—ensuring that you can begin high-power observing shortly after setting up.

Versatile Photo/Visual Hybrid

Though labeled as a "Photo" reflector, the 150/750 is equally adept at visual astronomy. The included 28mm LET eyepiece offers a generous 20mm of eye relief, making it exceptionally comfortable for users who wear eyeglasses.

Superior Value per Inch

Because mirrors are less expensive to manufacture than large glass lenses, this Newtonian design provides a massive 150mm aperture at a fraction of the cost of a similar-sized refractor. This makes it the ideal choice for budget-conscious astronomers who don't want to sacrifice light-gathering power.