Cloud Break Optics

0.77x Reducer/Flattener for Esprit 150 (S20215)

0.77x Reducer/Flattener for Esprit 150 (S20215) - Main image
$325.5 $525 In stock

Category: Astrophotography Accessories

  • 36mm fully illuminated field, compatible with both APS-C and full frame sensors
  • 90mm back-focus (55mm when back focus spacer and M48 ring installed)
  • Drops f/ratio from native f/7 (1050mm) to f/5.4 (810mm)
  • Reduces exposure time by 68% compared to native f/7
  • 2.54 x 1.7-degree field of view when used with a full frame camera
  • 1.66 x 1.11-degree field of view when used with APS-C crop sensor
  • Includes reducer, metal thread-on caps, back focus spacer and M48 thread adapter
  • Built-in 2" filter cell for mounting filters into the light path
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Customer Reviews (4.6 / 5 · 5 reviews)

Joshua ★★★★★

I was worried about back-focus compatibility with my full frame setup, but the included spacers made it dead simple to hit 55mm. The drop from f/7 to f/5.4 cuts exposure times noticeably, and stars are sharp corner to corner on my APS-C camera.

Brian ★★★★★

The 36mm fully illuminated field covers my full-frame sensor perfectly, no vignetting at the edges. Dropping from f/7 to f/5.4 cut my sub-exposure times by about 40%, which is exactly what I needed for my narrowband setup.

Benjamin ★★★★★

Tried it last night with my APS-C camera and was thrilled to see pinpoint stars across the entire frame—the 36mm fully illuminated field really delivers. Dropping the scope from f/7 to f/5.4 cut my exposure times noticeably, and the back-focus setup with the spacer was straightforward.

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