Dead-simple shutter speed tester from old mouse parts - Make:
ALVANDI Shutter Speed Tester
How to test your camera's shutter speed using lasers and an Arduino
Introducing the PhotoPlug – Easy Shutter Speed Testing for Your Smartphone - Silvergrain Classics
Film Shutter Speed a simple test method | Photrio.com Photography Forums
At-Home Test to Troubleshoot Shutter Speed Issues » Shoot It With Film
Phochron XA Film Camera Shutter Speed Tester by Eric Bergstrom — Kickstarter
Arduino on X: "Talk about a 'flashy' first Arduino project! 📸 This Redditor created a Nano-controlled camera shutter speed tester: https://t.co/ktdlFH1lCY https://t.co/P1a9swx9xq" / X
Free shipping] Camera shutter speed tester (for 35mm film cameras) w/ LED light | eBay
DIY Arduino Camera Shutter Speed Tester. HOW TO, less than $10! - YouTube
Phochron XA Film Camera Shutter Speed Tester by Eric Bergstrom — Kickstarter