Sky-Watcher 0.77x Reducer/Flattener for Esprit 150

• 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