There are many differences between film and digital photography. To most amateur photographers they do not matter much. They prefer the convenience, ease of use and lower cost of digital cameras and are not going to revert to the film age. However understanding the differences can help taking even better photos and can also help when debating with friends about the future of film.
Following is a list of differences that are important to understand. The differences are listed in no particular order.
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The sensor: The most obvious difference between film and digital is the sensor used to take the photo. With film cameras a film sensitive to light is placed behind the lens. When a photo is taken the shutter opens for a predetermined period of time and light hits the film. The result is a photo "printed" on the film. To take a new photo the film has to be rolled and a fresh "clean" film is place behind the lens. With digital cameras a fixed electronic sensor (sometimes known as CCD) is situated behind the lens. The sensor is built from tiny light sensitive sensors each representing a pixel. When the shutter opens light hits the sensor and each pixel gets its "value". Put together all the pixels comprise one photo. To take a new photo the photo is saved on a digital media and the CCD is electronically emptied.
What does a different sensor mean? The main difference is in the Depth of Field. Since digital sensors are smaller in size than a 35mm film the depth of field will be much higher and in fact in most compact digital cameras almost infinite. The result is that blur backgrounds can not be created.
The cost of a photo: Photos taken with a digital camera literally cost nothing. The photos are kept in erasable memory and thus can always be discarded at no cost. Also the photos you would like to keep can be copied to digital media such as a computer's hard disk. With storage prices going down the cost of saving a photo on disk is practically zero. Film does cost money. With a film camera you have to pay for the roll of film, for developing the negative and for printing the photo. Every time you press the shutter button you spend money.
The capacity: With ever growing storage capacities digital cameras today can hold hundreds and sometimes thousands of photos on a single media. You can always have a few more in your pocket and changing is very fast. The result is that a digital camera has practically infinite capacity. You can shoot as many photos as you want and at the end of the day just dump them on your computer's disk. Film cameras' capacity is very limited. A roll of 36 photos can only hold 36 photos. After a roll is used changing to a new roll can take time and is not easy to do in scenarios such as darkness or a harsh environment. For that reason many professional journalists carry a few cameras on them and instead of changing rolls they turn and use another camera just so that they do not miss a shooting opportunity.
The feedback: One of the most important features of the digital camera is instant feedback. Almost all digital cameras include a small LCD screen. Once a photo is shot you can go back and watch it on that screen. The ability to see how the photo looks like results in better photos. If the photo is not good you can take another one. Being able to see the photos on the spot results in an educated decision how to fix a photo or how to better compose it. It takes a lot of the guessing away from photography. With film cameras there is no way to know how the photo on the film will look like when printed.
New shooting angles: Just a few days ago I took a great photo with my digital camera that I would have never taken with my film one. I shot a cat that was resting on little rock. I held the camera in my hand and positioned it down where it almost touched the ground and I started shooting. I probably took 50 or more photos. I immediately looked at the camera's LCD to review my photos and make sure they were focused and had the cat in them. The result was one great photo looking at the cat from the ground. I can not imagine myself just lying down on the dirty ground with a film camera looking through the viewfinder and perfecting that one shot.
With digital cameras you can actually take photos without having your eye glued to the viewfinder. Overhead shots where you raise the camera over your head are much easier to do since you can still see what the camera is shooting by just looking up at its LCD screen.
Correcting photos: With digital cameras photos can be corrected using photo editing software. Some correction abilities are built-in to the cameras but many more are available as software packages for your PC. With film cameras what you get is what you get. After the film is developed it is very hard to make any corrections. Usually if corrections are absolutely needed the negative or the printed photo will be scanned (i.e. converted to digital) corrected and then printed again (in a long and costly process).
Changing conditions: Every roll of film is designed for best results in a specific environment. For example there are indoor and outdoor films or films with different light sensitivity. If conditions change rapidly a film camera user will have to either shoot with the wrong film, change the roll (and usually lose photos that were not used in the current roll) or use another camera with a different film in it. The results of shooting with the wrong film can be distorted colors (reddish photos for example), a grainy photo and more.
With digital cameras the characteristics of the sensor can be changed instantly for each photo taken. With a click of a button the camera can be put in an indoor or outdoor mode, low light, night photography etc. Some cameras will automatically sense the scenario and set the sensor mode accordingly.
The myth of quality: While it is true that film photography has its advantages the claim for superior quality is no longer true. As digital camera evolved the quality of high end digital SLR cameras is superb and in many ways even better than film. When considering quality you should also consider the quality in terms of composition and the scenario caught in the photo. With digital cameras' high capacity, zero photo cost and instant adaptability to changing conditions photographers can produce better compositions and experiment more to get the best photo possible.
Longevity: We have also paged through old photo albums of our grandparents. The photo looked a a bit yellow, scratched and just plain "old". Storage of printed film photos or even negatives results in quality deterioration. Digital photos on the other hand never lose their quality. A digital photo will be identical today and 500 years from now. As long as we remember to refresh the digital media every now and then and to back it up our photos can literally list forever and not lose their quality.
The aberration amid blur and agenda photography
