The 0.8x reducer can bring Askar 103APO's focal ratio down to F5.4. This is a standard reducer with field flattening capabilities as well. A shorter focal ratio allows the OTA to have a wider field of view and faster exposure times.
The 1x flattener does not change the telescope's focal ratio itself. After connecting with the Askar 103APO, it still maintained a focal length of 6.8.
Designed for serious Astro-Imagers. Optimised for the Evostar-72ED PRO, this superb quality accessory effectively reduces the telescope’s focal length by a factor of 0.85x and provides much improved field-edge correction.
Brand new adjustable field flattener for the William Optics Zenithstar 61 OTA. This is a brand new 2019 item which is now in stock at Rother Valley Optics.
Brand new adjustable field flattener for the William Optics Zenithstar 73 OTA. This is a brand new 2019 item which is now in stock at Rother Valley Optics.
This very elegant 2" reducer/field flattener has been designed to optimize the flat-field imaging performance of William Optics F/6 to F7.5 ratio refactors. WO Flat 6Alll will provide good illumination and flat field across 97% of full frame sized sensors.
The Takahashi 1.01x flattener has been introduced to cure the mild field curvature and edge of field astigmatism when using larger format cameras. The focal ratio is slightly increased when using this accessory.
Two-element design incorporating one ED element. Reduces the standard focal length of the Evolux-82ED by a factor of 0.9x and provides top quality field-edge correction.
Takahashi has released a new flattener for use with FS and FC series telescopes that is an improvement when compared to previous flatteners available for these telescopes.
Two-element design incorporating one ED element. Reduces the standard focal length of the Evolux-62ED by a factor of 0.9x and provides top quality field-edge correction.