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Pentax 645 Helicoid Extension Tube (43.7-67.4mm)

KEH Model# 290170

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* Item pictured for illustrative purposes only, actual item not pictured. See 'Notes' next to grade for included items.

Pentax 645 Helicoid Extension Tube (43.7-67.4mm) Description


Helicoid Extension Tube 645: Adjustable magnification by means of internal helicoid, can be used in Aperture Priority AE mode. Magnification can be adjusted from 0.57X to 1.06X with standard 75mm lens attached in normal position, or from 1.93X to 2.35X with 55mm lens attached in reverse.

KEH Specifications

  • Function: Increases the distance between the camera and the lens allowing for closer focusing and higher magnification ratio
  • Compatibility: Pentax 645/67/6x7
  • Step Range: 43.7 - 67.4mm
  • Note: Use of step-down rings can cause vignetting


General information

Brand Name Pentax
Product information

Physical Characteristics

Lens Mount Pentax 645 A