Explore Scientific 3" Field Flattener/0.7x Focal Reducer

Explore Scientific 3" Field Flattener/0.7x Focal Reducer

Explore Scientific 3" Field Flattener/0.7x Focal Reducer

B&H # EXFFFR507X00 MFR # FFFR507X-00
Explore Scientific 3" Field Flattener/0.7x Focal Reducer

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Product Highlights

  • For Astrophotography/Astro-Imaging
  • For 1.25" Focusers, 2" Adapter Included
  • Corrects for Spherical Aberration
  • Reduces the Focal Ratio by 0.7
  • Fully Mutlicoated Optics
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Explore Scientific FFFR507X-00 overview

  • 1Description

The 3" Field Flattener/0.7x Focal Reducer from Explore Scientific is a dual-purpose accessory for astrophotography and astroimaging. Use the two pieces together or separately to finely tune your telescope for capturing the best possible images. As a field flattener, it corrects for the inherent spherical aberration of curved lenses. Uncorrected, this aberration causes images to appear distorted at the edges of the field of view. As a focal reducer, it reduces the focal ratio of the scope by 0.7x, which translates into wider fields of view with shorter exposure times. This fully multicoated optic fits 1.25" focusers and comes with an adapter for use with 2" focusers.

UPC: 812257014408
In the Box
Explore Scientific 3" Field Flattener/0.7x Focal Reducer
  • 2" Focuser Adapter
  • 2 x T-Thread Adapters
  • Limited 1-Year USA Warranty, Extendable to Transferrable Lifetime Warranty with Registration
  • Table of Contents
    • 1Description

    Explore Scientific FFFR507X-00 specs

    Dimensions 3.5 x 3.1" (9.0 x 7.8 cm)
    Weight 22.6 oz (640 g)
    Packaging Info
    Package Weight 2.9 lb
    Box Dimensions (LxWxH) 7.4 x 6.6 x 6.2"

    Explore Scientific FFFR507X-00 reviews

    3" Field Flattener/0.7x Focal Reducer is rated 5.0 out of 5 by 3.
    Rated 5 out of 5 by from Superior Astrophotography I have a Explore Scientific 127mm triple refractor which is f/7.5 The 3 field flattern reducer increases my telescope speed by decreasing the f ratio to about a f/5.2 and gives sharp stars to the edge of the field in my photographs. The item works perfectly with my Explore Scientific telescope.
    Date published: 2015-04-28
    Rated 5 out of 5 by from Great focal reducer and field flattener This is a top-notch focal reducer and field flattener.� I tested it with the Lunt 152mm f/7.9 refractor and a full-frame camera (Canon 6D) just to see how good it is.� Exactly 0.7x reduction, and even on that full-frame sensor, stars are pinpoint sharp edge-to-edge.� I was astounded!� The only problem that I found, which always affects these setups, is vignetting.� That could probably be improved if Explore Scientific put a 48mm instead of a 42mm camera adapter on the unit, or made one available.� I could not find anything on the market that size that fits this reducer.� Vignetting is less of a problem if you are using a camera with a smaller sensor, such as APS-C or still smaller ones.� Also, don't forget that if you want to use this with a 2" draw tube (which most scopes have), you'll need to buy the 2" adapter, ES part #510364.� I don't know if B&H sells that but it is available.
    Date published: 2017-11-26
    Rated 5 out of 5 by from Excellent flattener/focal reducer I have the removable dew shield ES127ED APO model. I unthreaded the 3 barrel and used the Adapter 1 to thread the flattener/focal reducer directly to the focuser drawtube. I then threaded my SBIG ST2000xm to the front of the FR using the CCD camera adapter t-threads. The star field is tack sharp from edge-to-edge, no aberrations.
    Date published: 2016-02-10
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