Film is a technological marvel. My opinion might be skewed because I am a science geek. Oh well. It's still amazing. Can we take a minute and look at how it works? Skip to the next section if you're not interested.
How Photographic Film Works
Let's start with "simple" black and white film. If you were to unravel an undeveloped roll of film and separate it from the paper backing, what you would be left with is a plastic base covered in an emulsion made up of millions of light-sensitive silver halide crystals suspended in a gelatin layer. When the shutter is depressed and light strikes the film, photons liberate the electrons on a given silver halide crystal causing the reduction of silver ions and the formation of metallic silver atoms. The more light that strikes a given crystal, the more metallic silver atoms are formed. At this stage, a latent image is formed, which is basically an invisible image waiting for development. The appearance of film with a latent image does not differ from unexposed film.
When exposed to a developer, silver halide crystals with enough silver atoms are converted to macroscopic silver particles, which appear black to the naked eye. These silver particles remain on the film during the fixing process and the remaining unused silver halide crystals are washed off. At the end of the development process, what you are left with is a "negative" or reversed image.
Seen above is a scan of a film negative from a black and white roll after developing.
Prior to the invention of scanners, all photo printing was performed in the dark room using enlargers, photographic paper, and another set of chemicals. By projecting light through the enlarger and the film negative onto photosensitive paper, another latent image is produced. Once taken through a development process, a "positive" image is created on the paper. Today, it is possible to forgo this part of the process, although some film enthusiasts may strongly disagree. In my current workflow, I simply scan the film negative and a positive image is created using software. It isn't as fascinating as the darkroom process, but it certainly is more practical when you are lacking space and time.
Seen above is the "positive" image created from a negative film scan and software processing.
Color film works in a similar fashion, but involves several emulsion layers, each capturing a different color, as well as protective layers in between each emulsion layer. Because of the complexity of color film, the required labor to manufacture it is much greater compared to black and white film. Thus, only a few factories remain in the entire world.
Poloraid or instant film is the most complex of them all. It basically has all the chemistry of film itself and the developing process wrapped up into one small and scientifically precise package. Here is an excellent video put together about instant film.
Sustaining these high-output factories does not make financial sense since the world has mostly shifted to digital. Thus, we have seen factory closures of larger companies such as Kodak. Interestingly, the rise and sustainment of companies such as Lomography and the Impossible Project have clearly demonstrated that there is still a market for film and instant film. More recently, an Italian group by the name of Film Ferrania had their kickstarter campaign successfully backed and will be building a new factory using the parts from an older factory, which was originally founded in 1923. This group recognized the desire for film and instead of trying to sustain the old factory designed for the larger demand of the past, they decided to build a new smaller factory to meet the needs of today's market.
Why Keep Film Around?
Here are the reasons that keep me coming back to my analog cameras.
1) No LCD on the Back
With digital it is easy to want to preview each shot after it is taken, which leads to a couple of unhealthy habits. First, you're missing out on the moment while staring at the back of the camera. Secondly, one tends to make negative judgments about themselves with each preview, which can affect the rest of the shooting for the day. On the opposite end of the spectrum, one can become complacent and not want to chase after that perfect shot. With film, you have no idea whether or not you captured the moment. The only choice is to keep shooting until you think you got it.
2) Distancing Yourself from Your Shots
On a similar note, not being able to instantly download your shots onto your computer and being forced to wait for your film to be processed before being able to view your images allows you to lose the emotional attachment. Everyone loves their own shots more than their peers. That is the honest truth. By waiting to view your images, you are able to distance yourself from your photos and let yourself make judgements based on photographic principles such as composition and light instead of emotion.
3) Learn from Mistakes Faster
Did you meter correctly? If not, the roll will be blown, not just one frame.
3) Less $$$ Upfront
Film cameras can be had for pennies compared to their digital counter parts. Admittedly, the learning curve for analog photography is a little steeper, but it isn't anything a little internet browsing can't solve. Although the upfront cost of analog is much lower, it is important to consider the time, space, and financial cost required for processing and development of your film before investing in an analog system.
4) Access to Larger Formats
Although digital is now commonplace in the 35mm format, getting into digital systems for medium format (MF) will cost you an arm and leg. New digital backs for MF systems can cost anywhere from $15k - $60k and that is just the back. You would still need a body and lens (add another $5-10k). Digital solutions for large format (4x5 and above) do not exist at this point in time. If you want to shoot that, you will have to look to analog.
5) The Aesthetic
This is the hipster response. Simply put, there is a feel to film that cannot be denied.
6) Conversation Starter
Analog cameras always tend to draw eyes and make it easier to break the ice with strangers before taking their portrait. In most cases, the person you are talking with has previous experience with analog photography and loves to reminisce about it as much as you do.
Many past analog shooters tell me they have shot enough film and digital is all they will shoot now. From a business standpoint, I completely understand. The high output and fast turnaround time of digital cannot be matched by analog photography. But from an artistic standpoint, analog does offer something different, both in workflow and aesthetics. It is a nice change of pace, especially for those born in the digital age.