Explore Scientific’s ED Essentials line promises true triplet apochromat performance at a price almost as low as most ED doublet refractors. In this review, we’ll be looking at the largest of the Essentials scopes, the 127ED.
The Essentials scopes are sold mostly for visual users or those on a budget. If you’re interested in serious deep-sky astrophotography and are willing to spend a few hundred dollars extra, the FCD100 upgrade offers (at least theoretically) slightly better color correction, hexagonal focusers which are more suitable for heavy cameras, and a larger unvignetted image circle, in part due to the said focuser. Visually, however, the difference is basically unnoticeable and thus most of my comments on the Essential 127ED can also apply to the FCD100 version.
Both the Essentials and FCD100 127ED are available with carbon fiber tubes. These lighten the scopes by a few pounds and avoid the expansion/contraction problems that can sometimes occur when imaging with a metal tube.
With all that in mind, let’s get to this review.
Overview of Essentials 127ED
The Essentials 127ED uses Hoya FCD1 glass, which is basically the same as Schott/Ohara’s FPL-51. This is cheaper than the FPL-53 glass widely used in most doublet ...