William Optics 1.25" 90-deg Erecting Prism Diagonal for RedCat/WhiteCat 51 only (Silver) # D-EP90-125-RC51-SL
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Product Details
William Optics 1.25" RedCat Erecting Prism Diagonal (For Select RedCat 51 Telescopes Only - I, Ix, II (not for use with II-U))
This high-quality William Optics erecting prism diagonal provides a "correct" image when observing with the William Optics RedCat 51 telescope. When observing with this diagonal, "up is up" and "left is left" which makes it the perfect accessory for terrestrial daytime observing. The precisely engineered diagonal prism is made from anti-reflection coated BAK4 glass for maximum image quality and light transmission. It also includes a matte blackened interior to reduce internal stray light reflection and maximize contrast. The diagonal is made from CNC-machined 6061T aluminum and incorporates a silver aluminum anodized plate.
Its 1.25" barrel accomodates any 1.25" eyepiece. However, while many eyepieces will reach focus, not all will be able to do so due to the limited backfocus availability. We are unable to advise you which eyepieces may come to focus and which might not.
Attaching the Diagonal to a William Optics RedCat Telescope
The RedCat telescope has very limited backfocus and cannot accept regular 1.25" diagonals, even if attached to the telescope's terminal M48 male thread via a suitable thread-converting adapter. This special RedCat diagonal has a male M56x0.75 thread on the telescope side. In order to attach the RedCat diagonal to the telescope, you must first remove the telescope's rear tilt adapter to access the RedCat's M56 female thread.
Two important things to note:
1) You will require a 1.5mm Allen key/wrench to remove the tiny screws on the removable adapter on the scope. This is not included with the diagonal. Newer RedCat scopes include this Allen key (earlier shipments of the Redcat did not).
2) Once you remove the adapter to attach the RedCat diagonal, you will no longer have access to the internal M48 female threads to attach 2" threaded filters, which is not usually a problem for terrestrial viewing.
Manufacturer part number: D-EP90-125-RC51-SL
Other Information
- Country of Manufacture: Taiwan
