Most professional photographers use 35mm or digital single lens reflex (SLR) cameras. However, medium format cameras that use 120 and 220 roll film are on the market. Presently, the smallest available medium format is 645, which means 6 x 4.5cm picture size. The largest normal format is 6 x 9cm. However, some models use formats such as 6 x 12 cm. Medium format photos can also be taken on 4x5 large format cameras by using roll film backs attached to them.
Some medium formats have interchangeable backs and can use high resolution digital backs. Medium formats are useful when 35mm quality isn't sufficient and large format is too costly or slow. Many wedding and portrait photographers use medium format as larger style cameras take photos with richer details. They also create larger negatives that can be retouched. Medium format cameras aren't as popular as other types and only about 25,000 professional-level models are sold in the U.S. each year. The main reason of the low numbers is because of the cost of the cameras- as they range in price from about $250 to over $7,500.
