Field Flattener f/5 to f/7 Congrats Featuring a seamless transition between

Featuring a seamless transition between interior and exterior appearance with color-matched ceramic coating

Base: Rum Cream

Hecho en Paraguay

The Explore Scientific field flattener is designed to work with telescopes with focal ratios between f/5 and f/7

Field Flattener f/5 to f/7 Congrats Featuring a seamless transition betweenWhen doing astrophotography with refractor type telescopes, the faster the focal ratio the more field curvature becomes a problem. Field curvature will appear in the corners of astrophotographs, making the stars smear perpendicular to the axis of the image. This is called coma coma is Latin for comet, because the stars look like comets. The more the curvature, the closer to the center the coma appears. The larger the sensor, the worse the coma.