- Place your lens at the 70cm mark of your meter stick (have someone hold it if you don’t have a lens stand)
- Place your Cardstock at the 100 cm mark of your meter stick (either have someone hold it up or find a way to tape it up)
- Put your sticker on the lens of your mini flashlight. Then hold your lens directly behind the lens and the cardstock. If all three don’t line up, move them so they do.
- Move your flashlight either forward or backwards until a clear image of your letter shows up on the cardstock
- Measure how far you are from your lens.
- Place your Cardstock in a different location and repeat.