S  

Savage Universal Corporation - Archival pages, Enclosures, Backgrounds & Stands 
Schneider Optics - Lenses, Filters, Loupes, Projection Lenses.
Sea and Sea Underwater Photography USA - Underwater Flashes
Sekonic - Flash & ambient/incidental exposure meters
Sea Life ReefMaster - Underwater Cameras
Sigma Japan - Main Website
Sigma France
Sigma US 
Silvestri - Exclusive Italian Cameras in Medium & Large format
Sinar AG - View cameras and digital backs
Singh-Ray Filters - Creative & Colourful filters
SlideScribe - Slide captioning software, labels, archival storage
Slik - Tripods and accessories.
Speedotron - Industrial, Professional Flash Systems
Sprint Photochemicals - Extensive range of B&W chemistry
Sto-Fen - "Bounce Flash Specialists"
Strato studio accessories - Articulated "extra hand" - useful!
Stroboframe - Eliminate shadows and red eye
Studioball ballheads from J.P. Graf
Studio Dynamics Backdrops - Handpainted Backgrounds
Sunpak - Flashguns for Pro/Amateur use, Videolights, batteries