Optics & Photography
Wide Converters

Olympus PTWC-01 wide converter - test pictures

Olympus PTWC-01 Magnification: 0.6× underwater (approx).
Configuration: 4 elements, 4 groups,
AR coated.
Mounting: M67 screw thread.
dot_bu Depth rating: 40 m (has internal air spaces).
Dimensions /mm: 130.5 Ø, 68.6 L.  
: 1.086 kg
verboten Not designed to work in air.
Olympus PTWC-01
verboten Will block camera's internal flash (use external light source if artificial light is needed).
vignet Rear optical aperture: 50.8 mm - sufficient for 28 mm camera lenses if port to entrance pupil distance is not too great (zoom in slightly or crop image later if vignetting occurs).

Pictures taken using Canon S100 camera in ikelite housing.
Corner detail images have been resized to 2582 × 1937 (5Mp) before cropping.
Underwater light source: 2× ikelite Pro 2800 video lights. 

ptwc01_24 ptwc01_24dt

ptwc01_28 ptwc01_28dt

ptwc01_35 ptwc01_35dt

ptwc01_50 ptwc01_50dt

redstar Star performer
Lens shows slight vignetting with the S100 camera at f = 28 mm (35 mm equiv.) but this will be pushed out of the picture if radial correction is used. Images show exceptionally low chromatic aberration given the relatively large port to entrance pupil distance imposed by the 5× zoom lens of the S100 camera. The excellent optical quality can be attributed to the very large exit aperture. Pictures taken with this adapter can be exhibited at high magnification without the need for additional correction. Assuming a screen resolution of 96 ppi, the corner detail images are as they would appear with the picture displayed at 27 × 20" (68 × 51 cm).

  David Knight

Pictures by Steve Knight
© David W Knight & Stephen D Knight 2012, 2018

Optics & Photography
Wide Converters