Celestron 1.25" Universal Barlow and T-Adapter

This 1.25" accessory serves three functions:

• 2x Visual Barlow: Doubles the magnification of any 1.25" eyepiece you insert into it.
• Prime Focus T-Adapter: After unscrewing the lens element, it connects your DSLR/SLR camera (with a T-Ring) to the telescope, using the scope's native focal length.
• "Barlowed" T-Adapter: It connects your camera to the telescope and uses the lens element to double the imaging magnification, which also helps achieve focus on scopes with limited travel.

Yes. You will need a T-Ring that is specific to your camera's brand and model (e.g., Canon EOS, Nikon F-mount). The T-Adapter has the male T-threads, and the T-Ring has the female T-threads on one side and the camera's lens mount on the other.

Yes, this is exactly what the "tele-extended" mode is for. By keeping the Barlow lens element attached to the T-adapter, the focal plane is extended outward, which typically provides the extra focus travel needed for fast refractors and Newtonians to achieve a sharp image on the camera sensor.

For an 8" SCT, you have two great options. For a full-disc image of the Moon, use the adapter in prime focus mode (Barlow lens removed). This uses the telescope's native ~2000mm focal length. To capture close-up details of specific craters like Copernicus or Tycho, use it in tele-extended mode (Barlow lens attached) to double the effective focal length to ~4000mm.

No, one of the key benefits of this design is that it doubles the magnification while preserving the original eye relief of the eyepiece you are using. This is especially helpful for eyeglass wearers who rely on the long eye relief of low-power eyepieces.

While the product is designed for high-contrast views, the manufacturer does not specify the exact coating details. It is engineered to provide sharp, 2x magnification for both visual and imaging applications.