Glasseye Snapper (Bart)

Forum username: glasseye snapper
Real name: Bart
Posts: 721
Active years: 2005—2024
Primary forums: Photography Gear and Technique, Critter Identification, Shooting Technique/Workflow/Editing
Specialization: Optical science applied to underwater photography, fish biodiversity, mirrorless camera systems

Community Role

Glasseye Snapper (Bart) was a distinctive voice on Wetpixel who combined deep scientific and technical knowledge with a passion for marine life identification. Originally from the Netherlands, Bart moved to Canada in 1994 and became active on Wetpixel from 2005. His 16-year active span (2005—2024, with gaps in 2018 and 2020—2022) made him one of the community’s most enduring contributors.

Bart’s username references the glasseye snapper, a nocturnal reef fish — fitting for someone whose interests bridged photography and marine biology. His posts were characteristically analytical, often bringing scientific rigor to discussions about optics, light physics, and filter performance. He regularly participated in critter identification threads, particularly for gobies, blennies, and other small reef fish from the Caribbean, Red Sea, and Indo-Pacific.

In his 2023 reintroduction to the community, Bart explained that he had retired and planned to spend 4—6 months per year diving, primarily in the East Indies region. He reported completing a 3-month PADI AWARE Foundation-funded fish survey in Dauin (Negros Oriental, Philippines), documenting 790 fish species, including many never before reported from the Philippines and a few believed to be new to science (^[1]).

Notable Contributions

• “Magick Numbers” analysis (March 2006): Bart’s most celebrated contribution was a detailed scientific analysis of Magic Filters for underwater photography. Using spectral measurements and computer simulations of light transmission in pure seawater, he calculated the theoretical performance of color-correcting filters at various depths. He demonstrated that the Magic Filter’s “sweet spot” was in the 6—10 meter depth range, and suggested that going deeper would require stacking filters or combining with green-attenuating filters. Alex Mustard praised the analysis, noting it aligned with real-world experience (^[2]).

• “Mirror, mirror, on the wall…” (March 2014): Authored a comprehensive comparison of mirrorless (CSC) versus DSLR systems for underwater photography, covering autofocus performance, continuous shooting speed, image quality, sensor size trade-offs, and system maturity. The analysis was technically rigorous, citing lens rental testing data and covering practical implications for underwater photographers. This thread (21 replies) became a reference point for the community as mirrorless adoption accelerated (^[3]).

• Ikelite 7D housing thread (December 2009): First to flag the availability of the Ikelite Canon 7D housing on Wetpixel, starting a 25-reply discussion about this important new product (^[4]).

• Red Sea rhinoceros blenny discovery: Documented an unidentified blenny species from shallow waters at Marsa Shagra, Egypt. After posting to Wetpixel, Bart contacted blenny expert Ben Victor, who forwarded the images to Jack Randall and Sergey Bogorodsky. The fish remained unidentified, with the conclusion that it could be an unknown species. Alex Mustard later added a photo of what appeared to be the same species (^[5]).

• Dive site mapping (March 2014): Explored GPS-based techniques for mapping dive sites, researching affordable GPS trackers and photogrammetry approaches for a citizen-science project at Twin Rocks, Anilao (^[6]).

• Technical article comments: Provided scientifically informed comments on articles, including a question to Stephen Frink about diopter optics on wide-angle lenses that prompted a substantive exchange about field-of-view effects (^[7]).

Equipment

• Canon crop-sensor DSLRs (20D era, later 7D era)
• Ikelite housings
• Olympus OM-D mirrorless system (later years)
• Various macro lenses (Canon 100mm, Olympus 60mm)
• Sigma 150mm macro
• Subsee and Nauticam SMC close-up lenses

Fish Biodiversity Work

After retirement, Bart shifted focus to fish biodiversity surveys, conducting a PADI AWARE Foundation-funded survey in Dauin, Philippines (early 2023) that documented 790 species. His subsequent travel plans included extended stays in Dauin, Raja Ampat, and Pulau Weh (Sumatra). His dive site documentation project at biodives.com reflected this citizen-science orientation.

Activity Profile

• Peak years: 2006—2014
• Threads started: 78
• First post: 2005-10-12
• Last post: 2024-04-23
• Forum focus: Photography Gear and Technique, Critter Identification, Shooting Technique, Conservation, Trip Reports
• Comments on articles: 2