Apochromatic Refractors

Choosing an apochromatic refractor: the optical benchmark for astrophotography

An apochromatic refractor brings colours precisely to a common focus through combinations of high-precision optical glass. With no secondary mirror obstructing the light path, it delivers a deep black sky background and pin-sharp stars, free from unwanted colour fringes.

The different designs available:

• Astrographs with integrated correctors (Petzval designs, quadruplets or quintuplets): The Askar ranges (PHQ, FRA) and William Optics models incorporate their corrector lenses directly into the optical design. They ensure a perfectly flat field from edge to edge on medium-sized and large sensors, without complex back-focus spacing calculations.

• Modular doublets and triplets: Highly versatile and lightweight, these optical tubes adapt to all your interests. Add a simple focal reducer to photograph deep-sky nebulae, or a suitable eyepiece to explore the surface of the Moon and the planets.

• Ultra-compact portable models (40 to 72 mm apertures): Fine optical instruments designed for lightweight travel mounts, perfect for capturing vast Milky Way panoramas in just a few exposures.
  
  

Equipped with reinforced dual-speed focusers, these refractors support the weight of your cameras and filter wheels without flexure, ensuring trouble-free imaging nights and adjustments precise to the micron.