Extension tube
An attachment that can be placed between the body of the digital single-lens reflex camera and the lens to facilitate macro and close-up photography. Because there is an additional extension between the lens and the sensor, the lens is able to focus more closely and provide a more magnified image than would have been possible without the extension. There are a total of seven distinct magnifications available when using extension tubes, which are typically offered in groups of three. Extension tubes can be used singularly or in combination with one another.
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