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: 40m.
Dimensions /mm: 130.5 Ø, 68.6 L.  Weight: 1086 g
verboten Not designed to work in air.
verboten Will block camera's internal flash (use external light source if artificial light is needed).
Olympus PTWC-01

vignet Rear optical aperture: 50.8mm - sufficient for 28mm 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 = 28mm (35mm 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 96ppi, the corner detail images are as they would appear with the picture displayed at 27 × 20" (68 × 51 cm).

David Knight
© Cameras Underwater Ltd. 2012
Pictures by Steve Knight