GRAN TURISMO 81 IV F/5.9 APO TRIPLET

The William Optics Gran Turismo 81 Version IV is a three element apochromatic refractor with a focal ratio of f/5.9 and a focal length of 478mm. Utilizing FPL-53 synthetic fluorite glass, this telescope provides excellent aberration correction.

The 2.5" 10:1 rack & pinion focuser is smooth, stable and reliable, providing no slippage over long imaging sessions. The newly designed rotator allows you to precisely adjust the angle of your camera.

The CNC-machined and anodized handle bar with finder-style saddle is perfect for attaching a guide scope or other accessories. The Gran Turismo 81 also includes William Optics' innovative clear Bahtinov mask integrated into the lens cap.

William Optics uses high quality steel lens cells for their Gran Turismo and FLT triplet refractors. This is perfect for temperature compensation and will prevent pinched optics in cold weather conditions.

For best imaging results, it is recommended to pair the Gran Turismo 81 with its matching Flat6AIII 0.8x field flattener.

Note: As the Flat6AIII an adjustable flattener, you must adjust the distance for your specific telescope. See the Instructions tab above.

Specifications

Included items

• Gran Turismo 81
• Lens cap with Bahtinov mask
• Finder saddle handle bar
• 210 mm Vixen-style dovetail bar
• Soft carry case

Instructions

Note: Once you have unscrewed the rear adapter to the appropriate value in the table below, the remaining backfocus distance to make up will be 55mm from the rear M48 thread.  

Distance adjustment needed for correct backfocus