Telescopes & Astronomy

M48 11-Piece Stainless Steel Spacing Shim Set for precision back-focus adjustment in astrophotography. Includes shims ranging from 0.02mm to 1.0mm thickness, allowing fine-tuned spacing between your telescope and camera for optimal image quality.

Fine-tune your imaging train's back-focus distance with this 11-piece M42 stainless steel spacer ring set, featuring thicknesses from 0.02 mm to 1.0 mm. Combine multiple shims to achieve precise spacing adjustments down to hundredths of a millimetre—essential for eliminating star elongation and field curvature when using field flatteners, coma correctors, and reducers. Durable 304 stainless steel construction ensures each ring stays flat and rigid for years of reliable use.

Bring out the best in your nebulae astroimages with the H-alpha H-beta OIII (Hα-Hβ-OIII) Imaging Filter for the 8” RASA. This specialized filter allows high transmission of light from emission nebulae while blocking light pollution, helping to make your images pop with detail off the black sky background with superior contrast.

Fortunately, many sources of light pollution have relatively discreet emission spectra; they emit primarily at specific wavelengths of light. By strategically blocking these “bad” wavelengths, the filter essentially eliminates the effect of light pollution while letting the “good” wavelengths of light associated with the emission nebula pass through to the camera. You’ll notice much higher contrast in your images immediately, even if imaging from your light polluted backyard! And since the transmission at the key wavelengths is so high, the nebula will not be dimmed—only the background will be blacker.

• Enhance your 8” Rowe-Ackermann Schmidt Astrograph (RASA) by blocking light pollution, improving image contrast, and darkening the sky background.
• This filter selectively blocks wavelengths of light from sources of light pollution, such as streetlights, not broad regions of the spectrum.
• Does not block wavelengths associated with emission nebulae, keeping your nebula images bright and detailed.
• Fits into the 8” RASA’s integrated filter mount, maintaining peak optical performance.
• Optically flat surfaces free of defects, constructed of Schott glass with anti-reflection coatings.

• 24mm Ultra Flat Field eyepiece designed for 1.25” focusers
• Incredibly crisp views from center to edge of field
• Fully multi-coated, 8-element lens design for excellent light transmission
• Wide 65° apparent field of view allows you to see more of the night sky
• Generous 29mm eye relief and fold-down rubber eyeguard for comfortable viewing with or without eyeglasses
• Molded rubber grip ring for non-slip handling

• 18mm parfocal Ultra Flat Field eyepiece designed for 1.25” focusers
• Incredibly crisp views from center to edge of field
• Fully multi-coated, 8-element lens design for excellent light transmission
• Wide 65° apparent field of view allows you to see more of the night sky
• Generous 20mm eye relief and fold-down rubber eyeguard for comfortable viewing with or without eyeglasses
• Molded rubber grip ring for non-slip handling

• 15mm parfocal Ultra Flat Field eyepiece designed for 1.25” focusers
• Incredibly crisp views from center to edge of field
• Fully multi-coated, 8-element lens design for excellent light transmission
• Wide 65° apparent field of view allows you to see more of the night sky
• Generous 16mm eye relief and fold-down rubber eyeguard for comfortable viewing with or without eyeglasses
• Molded rubber grip ring for non-slip handling