A changing bag
is a bag specifically designed so that it does not allow light to enter while in usage. It is required for certain applications involving photosensitive
materials when a dark room
is not available. Common usages include removing film
from its canister to put it into a developing tank. They are also commonly found on the set of a film
, where the clapper loader
may need one if shooting on location or far away from a dark room.
It is handy to use when a darkroom is not available as is often the case in field shooting. It is also used in commercial photoprocessing labs, often to change paper.
A changing bag has two sleeves at one end for both the user's arms, and a zipper (often more than one, for double layered changing bags) to insert the tools and film needed. There are several sizes available, from smaller ones for many still photography applications to larger bags used in large-format still photography or filmmaking, which may need to hold both a magazine and a can of film stock which each have a 1000 foot capacity. Larger changing bag sizes are also available as "changing tents", where the top of the bag can be held in a dome-like configuration through the use of two curved rods.