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Explore Scientific 127mm FCD100 f/7.5 ED APO Triplet Refractor

SKU : ES-FCD100-127075-02

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  • Aperture: 127mm (5")
  • Focal Ratio: f/7.5
  • Focal Length: 952mm
  • Top notch refractor that is totally free of chromatic abberation

Product Details

  • Expose the wonder of Earth's celestial neighborhood with the Explore Scientific 127mm FCD100 Refractor. You'll experience the beauty of the barren lunar landscape, the smooth elegance of Saturn's ring structure, the most luminous deep sky objects in the Messier catalog, and more!

    For all intents and purposes, the 127mm FCD100 is the same instrument as the Explore Scientific 127mm Essential Series Refractor, but with higher quality optics. Explore Scientific uses Hoya FCD100 extra-low dispersion (ED) glass which has characteristics analogous with Ohara FPL-53 glass. With a true diffraction-limited optical design and compact size, the 127mm FCD100 is a premium quality refractor that has been made to inspire impromptu stargazing adventures.

    By combining Hoya FCD100 optics with Explore Scientific's proprietary EMD enhanced multi-layer coatings on all optical surfaces, the 127mm FCD100 air-spaced triplet refractor produces radiant images with high contrast while avoiding chromatic aberrations almost entirely.

    This incredible little scope also comes with a 2.5" Hexagonal focuser that features an extremely rigorous design and support for up to 10 lbs. of accessories.

    Even though the 127mm FCD100 is an outstanding telescope by itself, it is also small enough to mount on a larger instrument. This gives you flexibility when astro-imaging by splitting guiding and imaging responsibilities between the two scopes.

  • specifications

    Aperture127 mm (5")
    Focal Length952 mm
    Focal Ratiof/7.5
    Optical DesignTriplet Refractor
  • included items

    • Explore Scientific 127mm FCD100 f/7.5 ED APO Triplet Refractor
    • 2" Star Diagonal
    • 2.5" Hexagonal Focuser
    • Cradle Ring with Handle
    • Vixen-style Dovetail

Product Reviews

Customer Reviews
4.8 Based on 6 Reviews
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United States United States

Great optics for the price, hex focuser "ok"

Very happy overall with the 127mm-FCD100. When I bought it, I had the option for a FeatherTouch focuser, and looking back I should have added it. But I have installed a Rigel motorized focuser and it works well enough in my not so great environment. I use the OTA almost exclusively for narrowband imaging. My G-11 mount handles it easily and my only complaint is stray light from the streetlight across the street. With the primary lens up front, I have to ***** a shield to block stray light from entry into the instrument - wasn't a problem, of course, with my older SCTs - I should have recognized the potential problem but its easy enough to get around.

Dennis H.
United States United States

Great Refractor

I purchased mine over a year ago, I'm amazed with the optics on this scope. The FCD100 glass is amazing and I've been able to get several pics using my DSLR. I've recently upgraded to a ASI294MC Pro OSC camera and it really shows just how great the optics are on this scope. I can highly recommend this scope to anyone looking. The attached pic of M13 tells the story, and I'm not that good at post processing yet.

OPT Telescopes Explore Scientific 127mm FCD100 f/7.5 ED APO Triplet Refractor ReviewOPT Telescopes Explore Scientific 127mm FCD100 f/7.5 ED APO Triplet Refractor ReviewOPT Telescopes Explore Scientific 127mm FCD100 f/7.5 ED APO Triplet Refractor ReviewOPT Telescopes Explore Scientific 127mm FCD100 f/7.5 ED APO Triplet Refractor ReviewOPT Telescopes Explore Scientific 127mm FCD100 f/7.5 ED APO Triplet Refractor Review
Caleb S.

Solid Refractor

I recently purchased this scope along with some massive upgrades to my gear back in August and have been taking it for a spin almost every clear night we have here. For visual observation it has been really great, especially for planetary and lunar observation. I've been steadily working my way into DSLR AP and I've only hit one real issue with it and that is that I get these weird spikes when imaging stars that are in focus. The support team from ES has been very responsive in trouble shooting what might be the cause (probably the travel screws that come with it to help keep the optics in place), but I'll have to wait a week to do another test run. Overall, very, very pleased with this scope and the quality of my purchase. Thanks for all the help OPT for sorting through gear questions and helping with the purchase.

Stephen M.
United States

Great refractor

I upgraded to the Explore Scientific127mm f/7.5 FCD100 ED APO Refractor from the Explore Scientific 102mm f/7 APO Refractor that I have had for almost a year. The 127mm is a significant improvement over the 102mm. The images achieved are much sharper and larger due to the increase in diameter and FOV area. I am extremely pleased with both of the extremely fine Explore Scientific Refractors and would recommend them to anyone.

Roger S.
United States

5 inch APO Explore Scientific Refractor

I have never owned a refractor before. My only experience with telescopes has been with 8 inch and 10 inch SCT's which are awkard to setup. The 5" refractor is dong a fine job. It is much easier to setup and the view is more or less "the same" as larger scopes using mirrors. I am using a Celestron AVX mount which is what I had been using with the 8 inch Meade SCT OTA..

A OPT Telescopes Customer
Mike M.

Focuser needs work

Good glass. I stepped up from a 72mm doublet, and I use a 294 osc. My only complaint is the focuser. It's quite notchy. It will focus, but it's very rough. I made a few adjustments but it's not better. I may upgrade to a moonlite in the very near future. Great scope