William Optics RedCat WIFD Erecting Prism - 1.25"

This prism converts your RedCat 51, or any telescope with a 1.25" focuser, into a terrestrial spotting scope. It corrects the inverted and reversed image produced by the telescope, providing a view that is correctly oriented for daytime activities like birdwatching, nature observation, or surveillance.

While you can use it for casual stargazing, an erecting prism is not ideal for critical astronomical observation. The complex light path required to correct the image can introduce minor aberrations and light loss compared to a high-quality mirror or Amici prism star diagonal. For the best possible astronomical views, a dedicated star diagonal is recommended.

For birdwatching, having a correctly oriented image is essential for tracking moving subjects. This 90-degree prism ensures that when you move the telescope up, the view moves up, and when you move it left, the view moves left. This intuitive control allows you to follow birds in flight or locate them in dense foliage much more easily than with an astronomical diagonal.

A standard star diagonal corrects the image vertically but leaves it mirror-reversed (left-to-right). This is acceptable for astronomy but confusing for terrestrial viewing. An erecting prism, like this one, corrects the image on both axes, providing a fully correct, daytime-friendly view.

Yes, this is an excellent accessory for plane spotting. The fully corrected image allows you to track aircraft across the sky intuitively, and the 90-degree angle provides a comfortable viewing position when the telescope is pointed at high altitudes. The high-contrast optics will help you resolve details and airline liveries clearly.

Absolutely. This erecting prism uses a standard 1.25" barrel, making it compatible with any telescope that accepts 1.25" eyepieces and diagonals. You will just need to ensure your focuser has enough travel to reach focus with the prism in the optical train.