Flattener for Skywatcher ED50

• Two Lens Field Flattener
• Fully Multi-Coated
• 28mm Flat Field
• 6º Pinpoint Stars
• Back Focal Length 17.5mm
• 1.25" (31.7mm) Internal Diameter
• M42x0.75 Exterior Thread (T2)
• Green Anodised Aluminium Screw-on End Caps
• Net Weight 150g

Flatteners can be used to make the stars sharp even at the edges when taking photos with a refracting telescope without changing the focal length. The Flat-110 model even increases the focal length (by 10%). On the telescope side they provide 2" tube while on camera side a T2 mount is provided.

Some test images can be seen below with different flatteners and without any flattener.

The Standard Flattener is available at a very favorable price, but it corrects a slightly smaller field of view than the Universal model.

The Universal Flattener is the best choice for most of the apochromatic refractors. According to our test with most of the telescopes it provides an ideal correction up to APS-C sized sensors.

The Flat-110 is for Sky-Watcher's ED80 apochromatic refractor. The focal length is increased by 10% making a 80/660 refractor.

The ES Flattener ideal for 80/500 Equinox, can be mounted on a T2 thread.