| Year | 1955 |
| Date | 07-Jul |
| Volume | 113 |
| Issue | 2,824 |
| Page | 14 |
| Category | Photographic |
| Part | |
| Title | Testing Shutter Speeds |
| Author | R.G.Kennard |
| Notes | A Simply-Constructed Device, Equally Effective for Roller Blind or Sector Shutters. Rear and front views, test traces |