Film prices usually vary from country to country because of duty and local taxes and because the cost of processing is sometimes included in the price of the film. If you don't have a built-in electronic flash unit, take along a small accessory flash unit for your 35 mm camera. Batteries Most cameras need batteries to power built-in flash, exposure meters, and motors. So it's important to test your batteries and to replace them if they're weak. When you remove the batteries, replace them with the exact type recommended by your manual.
Invisible deposits can build up on battery contacts during shipment, storage, or use of equipment.
When this happens, the batteries may not work consistently and the flash will fail to go off. For successful flash operation, clean the battery and equipment contacts with a clean cloth or a water-dampened cotton swab. It's a good idea to start your trip with new batteries and to take a spare set with you. Refer to your camera manual for the size and type of batteries your camera needs. To help you remember places and names, take a notebook and jot down facts about the pictures you take.