William Optics RedCat 71 Flatfield APO

William Optics 71mm f/4.9 Redcat

It is a real Petzval Apo with a focal length of 350mm for widefield astrophotography.
The larger William Optics Redcat Apo with a diameter of 71mm and a focal length of 350mm is a real Petzval design. When the camera is in focus, you automatically have the best field correction and you don't have to consider the correct backfocus. When focusing, the entire small telescope unit is moved in the tube, the helical focuser is rubber-armored for a good grip and the mobility is adjustable. The optics convinced us in the test, the color correction is exceptionally good and the stars remain almost round up to the corners of the full format. Test results see photo tab. The lens is adjustable and the image can therefore be maintained by us.

Technical specifications:

• Focal length 350 mm / focal ratio f/4.9
• real Petzval design, no flattener and no backfocus problem - it automatically fits in focus
• extremely pure color optics (FPL-53 and FPL-51, 4 elements in 3 groups)
• Very well corrected and illuminated image field of 44 mm diameter - up to full format (see photo tab for flat and correction)
• better transmission than a photo lens with many lenses
• Camera connection via M48 external thread (previously M54 thread available)
• Focusing via precise and handy helical focuser, friction is adjustable
• Prism rail suitable for Vixen Level
• Standard finder shoe fits directly to the tube ring
• Carrying bag and Bahtinov mask for astrophotography integrated in the cap are included in the scope of delivery