Astrophotography Accessories

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.

M42 x 0.75mm Aluminium Alloy Extension Spacer Ring for telescope photography. This 15mm spacer can help you achieve precise back-focus spacing in your imaging train.

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.