Function

Photo enlargements are often used to showcase artwork in a gallery or to display family portraits.

History

Before digital photography, the quality of photo enlargements depended greatly on the speed, or ISO, of the film that was used. Faster films are more sensitive to light, but they create "noise" in photos that make for low quality enlargements. Therefore, the slower the ISO, the bigger an enlargement can be before it loses quality.

Digital Enlargements

In digital photography, ISO is still a determining factor in blown up images, but this setting can be changed instantly. In digital cameras, megapixels and file size settings are also important to consider for enlargements. More megapixels and larger file sizes provide higher quality enlargements without pixellation.

Types

Enlargements can be printed onto a variety of papers and other materials. Some printers offer services to blow up images on canvases and watercolor papers of varying textures.

Time Frame

One-hour services are available in most pharmacies and print shops for simple enlargements. Poster-size enlargements, or those on specialty materials, may take up to a week or more to process.

Source:

Photo.net: Film

GiantPrint.com: Glossary

Power-Graphics.com: Printing Materials