What does the 0.8x focal reducer in the ED80 bundle do?
The 0.8x reducer shortens the telescope's focal length from 480mm to 384mm and changes the focal ratio from f/6 to a much faster f/4.8. This provides a wider field of view and allows you to capture images with significantly shorter exposure times, which is ideal for deep-sky astrophotography.
How do I attach my DSLR camera to the Explore Scientific ED80 with the reducer?
You will need a camera-specific M42 T-ring (sold separately). The T-ring screws directly onto the male M42x0.75 threads on the back of the 0.8x focal reducer. A DSLR on a standard T-ring usually sits close to the required 55mm (+/- 2mm) of back spacing.
Is a mount included with this Explore Scientific ED80 bundle?
No, a mount is not included. The telescope has a Vixen-style dovetail bar, making it compatible with a wide variety of equatorial mounts. For long-exposure astrophotography, a sturdy German equatorial mount is required.
Can I use this ED80 telescope for visual observing of planets?
Yes, the ED80 is an excellent visual instrument. To use it visually, you would remove the 0.8x reducer and add a 2-inch star diagonal (the 2026 catalog lists a 99% reflective 2-inch diagonal with a 1.25-inch adapter for the ED80 Essential tube assembly) and eyepieces (sold separately). The native 480mm focal length provides sharp, high-contrast views with virtually no false color of the Moon, Jupiter, and Saturn.
What kind of mount do I need for astrophotography with the ED80?
For astrophotography, you will need a stable German equatorial mount. The tube weighs 3.4 kg; add your camera and accessories and choose a mount whose imaging capacity comfortably exceeds the total.
How does the ED80 handle chromatic aberration?
The ED80 uses an air-spaced triplet objective that includes one element made of HOYA FCD1 ED glass. This apochromatic design brings different wavelengths of light close to a common focus, virtually eliminating the purple fringing (chromatic aberration) often seen around bright stars in less corrected telescopes.
Is this ED80 bundle a good choice for imaging the Andromeda Galaxy (M31)?
Yes, this is an excellent setup for the Andromeda Galaxy (M31). With the 0.8x reducer, the 384mm focal length provides a wide field of view that can frame the entire galaxy, including its faint outer arms, when paired with a common APS-C or full-frame sensor. The fast f/4.8 ratio helps capture the faint nebulosity in a reasonable amount of time.
Will I need extension tubes to reach focus with the ED80?
The ED80 Essential's focuser system includes extension tubes to help accommodate different imaging and visual setups. Whether you need them depends on your specific camera and accessories. It's common to need them for visual use with a diagonal, and sometimes for imaging depending on your back focus requirements.
What is the difference between this Essential ED80 and the FCD100 version?
The main difference is the type of ED glass used. This Essential model uses HOYA FCD1 glass, which provides excellent apochromatic correction. The FCD100 series uses a higher-grade HOYA FCD100 glass, offering an even greater level of color correction, approaching that of fluorite lenses, and often comes with upgraded mechanics like a larger focuser.
Can I use this ED80 bundle to image Jupiter's Great Red Spot?
While the ED80 has excellent optics, its native 480mm focal length is quite short for high-resolution planetary imaging. To get a large enough image scale to resolve details like the Great Red Spot, you would need to remove the reducer and use a high-quality 3x or 5x Barlow lens (sold separately) along with a dedicated high-frame-rate planetary camera.
