Cerianthus (Gerard Wijnsma)

Forum username: Cerianthus
Real name: Gerard Wijnsma
Posts: 813
Active years: 2005—2022
Primary forums: Photography Gear and Technique, Critter Identification, Conservation and the Environment
Specialization: Canon DSLR with Ikelite housing, European diving, Dutch underwater photography community

Community Role

Cerianthus (Gerard Wijnsma) was a long-tenured Wetpixel member from the Netherlands, active for 17 years from 2005 to 2022. His username references the tube anemone genus Cerianthus, reflecting his marine biology interests. Gerard was a thoughtful and technically curious contributor who bridged the European and international underwater photography communities on Wetpixel.

Gerard brought a distinctive perspective as a Dutch diver who regularly shot in the challenging cold, murky waters of Northern Europe while also traveling to warmer destinations including Brittany (France), the Red Sea (Marsa Shagra), Scotland, and the Philippines. His posts often addressed the practical challenges of underwater photography in temperate conditions — limited visibility, cold water, RIB-based diving, and autofocus performance in low-light murky environments.

He was a Canon shooter using a 20D in an Ikelite housing with two DS-50 strobes, later upgrading to a Canon 70D. He was also a contributor to the Wetpixel editorial content, authoring a BOOT 2007 show report as a Wetpixel article (^[1]).

Notable Contributions

• BOOT 2007 show report (January 2007): Authored a Wetpixel article reporting on the BOOT Dusseldorf dive show, covering housing manufacturers including Sealux, Hugyfot, Seacam, Subal, UK Germany, and Subtronic. He also highlighted lesser-known German brands like BS Kinetics (carbon-fiber housings), Gun-Lux, and Silverfish. The report was illustrated with photos taken using his new Sigma 15mm fisheye (^[2]).

• Kees Opstal celebration (November 2007): Promoted fellow Dutch underwater photographer Kees Opstal (DuikKees) winning the Dutch Championship for Underwater Photography for the second consecutive year, noting wins in macro and wide-angle categories. Alex Mustard and Cor Bosman joined the congratulations (^[3]).

• Wetpixel favicon suggestion (November 2007): Suggested adding a favicon to Wetpixel, which Eric Cheng acknowledged as a “GREAT idea” and added to his to-do list (^[4]).

• Konica Minolta discussion (September 2005): Started a thread asking whether the underwater photography industry would ever support Konica Minolta DSLRs, prompting Alex Mustard to explain the economic realities of housing manufacturing and the trend toward fewer supported camera models. The thread proved prescient — Konica Minolta exited the camera business shortly afterward (^[5]).

• Lens and strobe compatibility: Contributed detailed discussions about lens trade-offs for European diving conditions, including the Sigma 15mm fisheye vs. Tokina 10-17mm debate, focusing on practical concerns like Magic Filter compatibility, autofocus speed in murky water, and DS-50 strobe coverage angles (^[6]).

• Practical diving logistics: Shared real-world problem-solving threads including transporting housed cameras on RIBs, dealing with strobe floods, and troubleshooting sync cord issues (^[7], ^[8]).

• Basking sharks lens choice (August 2015): Sought advice on lens selection for photographing basking sharks in Scotland with a Canon 70D, demonstrating his continued diving adventures in European waters (^[9]).

Equipment

• Canon EOS 20D in Ikelite housing (6871.20) with 4-port lock update
• Canon EOS 70D (later years)
• Two Ikelite DS-50 strobes
• Sigma 15mm f/2.8 fisheye
• Tokina 10-17mm fisheye (considered/acquired)
• Canon 10-22mm
• Canon EF-S 18-55mm kit lens
• Ikelite 5503 dome port
• Inon viewfinder (aftermarket)
• Vacuum leak detection system (aftermarket)

Timeline

• 2005-08: Joined Wetpixel, began participating in gear and technique discussions
• 2005-09: Started Konica Minolta housing discussion (^[10])
• 2007-01: Published BOOT 2007 show report on Wetpixel (^[11])
• 2007-05: Dealt with strobe flood on Ikelite DS-50 (^[12])
• 2007-07: Photographed while diving from RIBs in Brittany, France (^[13])
• 2007-11: Suggested Wetpixel favicon; celebrated Kees Opstal’s championship win (^[14], ^[15])
• 2007-12: Debated Sigma 15mm vs. Tokina 10-17mm trade-offs (^[16])
• 2014-04: Listed Ikelite 20D system for sale, indicating upgrade to newer system (^[17])
• 2015-08: Preparing for basking shark photography in Scotland with Canon 70D (^[18])
• 2022-05: Last recorded forum activity

Activity Profile

• Peak years: 2007—2015
• Threads started: 37
• First post: 2005-08-18
• Last post: 2022-05-11
• Forum focus: Photography Gear and Technique, Critter Identification, Conservation, Feedback, Shooting Technique
• Articles authored: 1 (BOOT 2007 show report)