Explore Scientific · Apochromat Refractor
Explore Scientific ED127 FCD100
A serious 127mm apochromat built around premium FCD100 glass, designed for sharp, color-free views across planets and deep sky.
Price updated Mar 22, 2026
Performance Scores
Overview
The Explore Scientific ED127 FCD100 is a 127mm apochromatic refractor with a 952mm focal length and a focal ratio of f/7.5, built around FCD100 extra-low dispersion glass. That glass choice matters: FCD100 is a high-grade optical material that keeps chromatic aberration tightly controlled, meaning stars render as clean points of light rather than showing the purple or blue halos common in cheaper refractors. At f/7.5, this scope sits in a comfortable middle ground, long enough to perform well on planets and the Moon, yet short enough to remain manageable for wide-field deep-sky work with appropriate eyepieces.
The 127mm aperture gives you a limiting magnitude of around 13 and a resolution of 0.9 arcseconds, which is sufficient to split close double stars and resolve fine planetary detail when seeing cooperates. Weighing 6.35kg, it is a substantial instrument and will need a solid equatorial mount to perform as intended, something like a mid-range EQ5 class mount at minimum. The carbon fiber tube helps keep weight from climbing further.
At $1,599.99, this is a considered purchase, and the low number of Amazon reviews means community feedback is limited, so factoring in broader forum research before buying is worthwhile.
At a Glance
127mm
Aperture
f/7.5
Focal Ratio
6.35kg
Weight
952mm
Focal Length
Specifications
Key Features
- FCD100 extra-low dispersion glass delivers well-controlled chromatic aberration compared to standard ED doublets
- 127mm aperture resolves detail to 0.9 arcseconds, capable of splitting tight double stars and showing planetary surface features
- f/7.5 focal ratio works across both planetary and wide-field deep-sky observing without requiring extreme eyepiece focal lengths
- Carbon fiber tube reduces overall weight while improving thermal stability during cool-down periods
- 952mm focal length is well-suited to mid-range eyepieces, giving practical, comfortable magnification ranges for most targets
- Limiting magnitude of 13 brings fainter deep-sky objects within reach, including many globular clusters and brighter galaxies
- Requires a solid equatorial mount rated for at least 7kg to maintain stable tracking and protect image quality
Customer Reviews
2 reviews
I had a model similar to this only in white. It was ok..but I had to buy a good (better) diagonal, and even with my high end eyepieces, it didn’t give me any better views than my reflector which I got for under 4 hundred dollars from GSO. I have found that Explore scientific is the most overpriced o...
You can expect the royal run-around if you ever have a problem or need warranty service. On two separate occasions the same agent (Wade) did not return emails or reply to voice mails. Once they know your number they stop answering your calls. So help requests were ignored, and then I get an email as...