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Camera and Photographic Equipment Repairer

Real-Life Activities

Real-Life Math

You are repairing a flash on an expensive camera. Once you have finished the repairs, you want to make sure the camera is operating properly, so you take some trial pictures.

"Cameras require a bit of math to figure out film speeds, apertures and shutter speeds," says Jennifer Elder, a camera repairer. The aperture is the size of the opening that allows light through the lens into the camera.

"We also use math to add up invoices, order parts and that type of thing," says Elder.

In order to calculate the flash range for the subject you are photographing, use the following formula:

Maximum flash range (in yards) = Guide number / aperture you selected
Minimum flash range (in yards) = Maximum flash distance / 5

There are a few variables you need to know. You are using an aperture of 3.5. You are also using an ISO 50 film speed. Use the following chart to find your guide number:

ISO Film SpeedGuide Number
256
508.5
10012
20017
40024

What are the maximum and minimum ranges of this flash?

Contact

  • Email Support
  • 1-800-GO-TO-XAP (1-800-468-6927)
    From outside the U.S., please call +1 (424) 750-3900
  • North Dakota Career Resource Network
    ndcrn@nd.gov | (701) 328-9733

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