Asahi Pentax Helicoid Extension Tube

The Helicoid Extension Tube is a handy 6x7 camera accessory which permits free variation of subject magnification, thus making it extremely handy for close-up and copy work with the Pentax 6x7, 67 & 67II. It fits between the camera body and the lens in use and permits focusing and composition while viewing directly through the viewfinder. Minimum and maximum magnifications obtained with the Helicoid Extension Tube very in relation to the lens in use, as do film-to-subject distance, picture area and exposure factors.

Works with all Asahi Pentax 6x7 lenses in the 55mm to 200mm range are adequate for close-up work without reversal. When high quality close-ups with ultra sharp resolution are desired to bring out the fine details of the subject, use of the 135mm F4 Macro Takumar Lens, optimised for close-up and copy work,is recommended.