Medium format

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Image:Film size comparison.jpg

Medium format is a film format in still photography. Generally, the term applies to any film size between 35 mm and large format (4"×5" or more) sheet film and to the type of camera that uses the format. Due to the higher image resolution offered by the larger film size, the majority of medium-format users are professional photographers who often require fine image detail, but the format is also favoured by many amateur enthusiasts.

Contents

Characteristics

The main draw to medium format is that, due to its increased film size (around three to four times bigger than 35 mm), it offers much higher image resolution. This allows for relatively big enlargements and smooth gradation without the grain or blur that would characterize similarly enlarged images produced from smaller film formats. While large-format film used in view cameras offer greater film size and higher resolution still, they generally lack the versatility and convenience of a medium-format camera due of their bulky size and relatively awkward processes.

Medium-format film can also be shot in a variety of aspect ratios, which differ depending on the camera or frame insert used. The most common aspect ratios are 6×6 cm (square) and 6×4.5 cm (rectangular). Other frequently used aspect ratios are 6×7 cm, 6×9 cm, and 6×17 cm panoramic. The 6×4.5 cm format is usually referred to as "645", with many cameras that use this ratio bearing "645" in their product name. Cameras that can switch to different aspect ratios do so by either switching camera backs, by using a frame insert, or by use of special multi-format backs. All of these dimensions are nominal; actual dimensions are a bit different. For example, 6×7 cm might give an image on film that is actually 56×70 mm; this enlarges exactly to fill an 8×10 sheet of paper. Another feature of many medium format models is the ability to use Polaroid instant film in an interchangeable back. Studio, commercial and architectural photographers value this system for its ability to verify the focus and exposure. Another pro is that, like large-format cameras, many medium-format cameras have various interchangeable parts. While most 35-mm SLRs support different lenses, it is standard for medium-format cameras to support different lenses, winding mechanisms, viewfinders, and camera backs.

Compared to 35 mm, the main drawbacks are accessibility and price. While 35-mm cameras, film, and photo finishing services are generally widely available and cheap, medium format is usually limited to professional photography shops and can be prohibitively expensive for some. Medium-format film also supports fewer exposures per roll, usually around 12 to 16, and are generally more difficult to load and handle than their 35-mm counterparts.

Medium format photography today

All medium-format cameras manufactured today use the 120 film format. Many also can use the 220 film format, which is twice as long and hence allows twice the number of exposures. A large number of medium format cameras capture 6x6cm exposures on the film, but there are also 6x4.5, 6x7 and 6x9 alternatives. When buying a used camera, it is necessary to ascertain whether it takes a film format that is currently easily available. Large sheets of film can be hard to find and expensive. 120 and 220 film is still almost as available as 35mm from speciallist shops.

Digital photography has come to the medium format world with the development of digital camera backs, which can be fitted to many medium-format cameras. Digital backs are a type of camera back that have electronic sensors in them, effectively converting a camera into a digital camera. These backs are usually very expensive and are used predominantly by professional photographers. Like with film, due to its increased size they deliver more pixels and have lower noise. Features like fan cooling also improve the image quality of studio models.

"Lomography" and other low-budget medium format cameras

While most professional medium format cameras are very expensive, some inexpensive plastic imports, such as the Diana and Holga, are gaining in popularity, particularly with toy camera enthusiasts. Due to the poor quality of the camera, the exact image captured on the negative is somewhat random in nature. These camera usually have distorted lenses that offer poor or uneven focus, light leaks that vignette or oddly colorize an image, and a multitude of other "flaws" that are generally undesirable to photographers. While these elements certainly are "flaws" in camera design, they can produce interesting, artistic, or enjoyable results. Because of the popularity of lomography and toy camera culture, medium-format photography has seen a resurgence with the amateur class. Lomography detractors point out that twin-lens reflex cameras (TLRs) and folders without the distortion and light leaks can be had on the used market in the same price range.

The Chinese Seagull TLR and medium-format cameras from the former Soviet Union such as the Russian Lubitel and somewhat better made Ukrainian Kiev-Arsenal 60 and 88 are also available at moderate prices. These cameras can deliver quality images, although the lenses and camera bodies are not at the level of those from Swedish, German and Japanese manufacturers.

Used folding cameras, TLRs, and box cameras are also cheap option to shoot medium format. Sadly many U.S.-made folders, including most of the mass produced Kodak folders use the discontinued 620 film requiring the user to respool 120 film.

Medium-format cameras

Types

  • Folding-bed field cameras

Additionally, most large-format cameras can, with the use of roll-film adapters, use medium-format film.

Common brands

"Classic" medium format cameras are collected and used by antique camera enthusiasts. Names like Graflex, Omega, Voigtländer and Zeiss can quicken a collector's pulse.

External links

sv:Mellanformatskamera th:กล้องกลาง