Takahashi has released a new flattener for use with the FSQ-85EDX telescope that provides a flat field like that of the FSQ-106EDX4 for full frame DSLR and CCD cameras. This flattener is available for pre-order, with expected delivery in late November 2017. When originally conceived, the FSQ-85EDX was meant for use with APS-C or smaller CCD or CMOS chips. At an image circle radius beyond about 14 mm, field curvature could become evident in larger chips. This new flattener will greatly reduce this field curvature, resulting in a practically flat field out to a 22mm image circle radius. The two spot diagrams below demonstrate the impact of the flattener on field curvature:
In addition, all FSQ-85ED scopes sold after January 1, 2018, will include the flattener as part of the basic telescope SKU. There will be a part number change and a slight increase in the base price of the FSQ-85ED OTA at that time.
Description: Flattener 1.01X for FSQ-85EDX
Effective Focal Length: 455 mm (f/5.4)
Image Circle Diameter: 44 mm
Metal Back: 56 mm