Some of you may want to use SIGMA 17-70mm F2.8-4.5 MACRO with SEA&SEA dSLR housing. SEA&SEA do not officially supports this lens with their housing. You know, SIGMA 17-70mm is a best lens for both wide angle and macro situation. I use to consider design/create custom zoom gear for this lens. However, I just found a simple solution for zooming SIGMA 17-70mm. Since, SIGMA 17-70mm is relatively large lens, you can zoom this lens with it’s weight. SIGMA 17-70mm with some filter zooms when a camera heads down. And also the lens widen when a camera points in the air.
