This page is designed solely to allow App Store reviewers without access to actual resistors to verify the functionality of ResistorVision. Actual users will use the app only with actual resistors.

It is more difficult to get a good reading with a screen image than it is with an actual resistor.

For best results:

  • Angle camera slightly downwards so screen doesn't pick up glare from iPhone's torch light. (With real resistors, the light from the torch improves color accuracy.)
  • Getting the distance from the screen right is a delicate balance.  Too close and the camera picks up moire patterns from screen.  Too far, and the camera won't be in focus. (Neither of these problems happen with real resistors.)
  • If you have a retina display, try shrinking the page (command-minus in Mac Safari) once or twice.  The higher resolution of the retina display will allow you to move closer to a smaller image without the camera generating moire patterns.


100 Ω (ohm) resistor



220 Ω (ohm) resistor



10K Ω (ohm) resistor