What is Large Format?
Strictly speaking, large format refers to a film size of 5 x 4 inches or bigger, such as 5″x 7″ or even the huge 8″x 10″ (that’s in inches!). Panoramic 6x17cm also falls into this class as large format because, although it uses medium format film (120 or 220 roll film), it uses a big slice at a time, 17cm in fact. Making it the same length as a piece of 5″x 7″ film.
All this is technical; the reality for the viewer is amazing clarity of colour, depth and sharpness, even when enlarged to enormous proportions!
This is due to the large area of film used for each shot, more than 11 times greater than a standard 35mm negative… for example, a print 1m long from a 35mm negative is enlarged 28 times from the original, whereas a 6×17 only needs to be enlarged 5.8 times to achieve the same result… in reality a 35mm negative runs out of steam at about A3, the film grain becomes very prominent and the image becomes fuzzy. At that size the 6×17 is just starting, that’s hardly an enlargement at all! So, as you can imagine, the potential is huge! (See a review of the Fuji 617 cameras here)
Medium Format Cameras
Medium formats are usually considered to be the ranges of 645 (6cm x 4.5cm), 6×6 (6cm x 6cm), 6×7 (6cm x 7cm) or 6×9 (6cm x 9cm). These formats were always the choice when dramatically higher image quality was required but without the bulk and difficulty of using a large format camera. Most medium format cameras are able to be used hand held, and some of them even take the form of large SLR formats, like a big 35mm camera (the famous Pentax 6×7). These medium format cameras take 120 or 220 roll film with the ease of use that comes with roll film, rather than loading double dark slides for each exposure as with large format cameras.
Digital Medium Format
All these parameters changed with the advent of Digital cameras. The first digital cameras were prohibitively expensive, slow and of very low quality, but since then they have caught up and overtaken film as the premium choice, both for quality and convenience. The current range of professional and semi professional DSLRs, such as the Canon 5D Mk II, are capable of shooting images of medium format quality and beyond, while the more expensive medium format backs, such as the Phase One Camera and the Hasselblad, exceed even 4″x5″ film quality. Due to the clean grainless nature of Digital capture, digital images are able to be enlarged many times over with little degradation of image quality and sharpness, assuming of course the necessary ingredients are there in the first place. ie: correct exposure, image sharpness, lens and camera quality.
Digital Vs Film
I have heard it said many times that the clean grainless look of a digital image looks somehow fake or unrealistic, but i think this is just habit. We are used to seeing photographic images with grain, it has become normal, and the grainless look of digital is still quite new. But where to from here? Will film vanish completely?
Film cameras are already vanishing from the scene rapidly in front of the advancing tide of digital technology, film has virtually disappeared altogether from the consumer market, and the majority of professionals have long converted over. What I would expect to see over the next few years is a dramatic shrinking of the Film market supply, down to perhaps one or two suppliers making one or two types of film, that perhaps you would need to order over the internet. Processing labs would also diminish to very few options, it may come down to posting your unprocessed films interstate or even overseas to have them developed. Everything from that point would be scanned and digitally printed (see this Post and this post for details), as is already the case now (apart from some smaller operators). The best simile would be the vinyl record industry when CDs became common, you can still buy vinyl, if you know the suppliers, and there are still many people who use nothing but.
See this related article about Depth of Field in medium format cameras.