Astronomy Specialist



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The SharpStar field flattener & reducer for the 140PH is a 3" dedicated corrector with a reducing power of 0.74x. It reduces the focal length of the 140PH to 673mm and the focal ratio to f/4.8.

This 3 element corrector delivers a fully illuminated and corrected field of 44mm, making the telescope compatible with full frame sensors. The working distance between the flattener and the sensor is 88mm.

The SharpStar flattener can be connected to the focuser of the Sharpstar 140PH by using the M88x1 male thread, and on the camera side there is the universal M48x1 male thread. The reducer can be rotated 360 degrees.

If more backfocus is needed, the top part of the flattener/reducer can be unscrewed. This extension has an optical length of 50mm and connect to the M74x1 male thread of the flattener/reducer.  


  Chromatic aberration 140PH + 0.74x reducer



Spot diagram 140PH + 0.74x reducer


Reducing power 0.74 X
Focuser connection
M88 x 1 male
Camera connection
M48 x 0.75 male
Backfocus distance
55 mm
Thread on the flattener/reducer toward the camera side M76 x 1
Extension / rotator details
50mm optical thickness, M76 x 1female to M48 x 0.75 male 
Optical elements
3 lenses


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