Askar 160 APO 1x Full-frame Flattener

1× field flattener for the 160APO refractor (Askar). This three-element flattener corrects the field curvature of the Askar 160APO for sensors up to full frame. Its 1× factor retains the 1120 mm focal length and f/7 focal ratio. The included adapters provide a choice of M68, M54 or M48 imaging connections.

Key features

• corrects a 44 mm image circle
• three-element optical design
• internal thread for a 2" filter

Included items

• field flattener 1× for 160APO
• three threaded adapters: M68, M54 and M48
• two threaded metal caps

Technical specifications

• compatible refractor: Askar 160APO
• focal-length factor: 1×
• number of optical elements: 3
• image circle diameter: 44 mm
• required backfocus: 55 mm from the base of the external M48 thread
• telescope-side thread: M92 × 1
• imaging connections: M68 × 1, M54 × 0.75 and M48 × 0.75
• internal filter thread: M48 × 0.75, for a 2" filter
• weight: 0.56 kg

Choosing the appropriate connection and maintaining the required backfocus enables field correction in a 160APO imaging setup.