Though different sorts of cameras use different media to store the images (film, memory sticks, CDs) there are certain factors in common for all photo media. Other factors, such as film speed ratings, apply to one form of photo creation but not the other.
Film and digital storage media are simply different ways to achieve the same result. Just as we refer to people of both sexes with the generic “him” rather than the more awkward “him/her”, we sometimes refer to “film” rather than using the more awkward “film or digital storage media.”
But the end result is the same. Whether your camera uses film or a memory stick, you’re capturing and saving an image for later manipulation and use.
Film size/pixel rating
In general, the larger the negative, the larger a print it is possible to make without loss of quality. But other factors enter into the quality of a potential print, including lighting conditions, film speed or sensitivity, and camera motion.
Enlarging the image means that everything on the negative will be enlarged – including the grain pattern of the film. High-speed film achieves its increased sensitivity to light by using larger grains of photo-sensitive silver in the film, so photos taken with high-speed film will be grainier than those taken with lower-speed film. If there is camera motion in the negative, it will be more visible as enlargements increase in size.
A very sharp, totally in-focus 35 mm negative, taken in good lighting conditions and with no camera motion, can produce prints as large as 30 by 40 inches. More commonly, a 35 mm negative will produce excellent 8 x 10s and acceptable 11 x 14 to 16 x 20 prints.
Digital cameras give the measure of their storage media in the number of pixels. Each pixel is a small square of digital information; each pixel is just one color. When thousands of pixels are lined up together, even though each one is a distinct color, the image blends together to the eye and creates the illusion of a range of colors flowing from one into the next. The smaller the pixels and the more of them which are combined to make an image, the smoother and more realistic the image appears.
When a digital image is enlarged, each pixel is increased in size. The larger the photographic blowup, the more likely it is that individual pixels will be visible.
Early digital cameras often produced images using one to two megapixels (one million to two million individual pixels). Though that sounds like a lot, each pixel is microscopic in size. So these cameras were good for small snapshots and emailed photos, but they did not create good enlargements. An 8 x 10 enlargement from such an image often began to look like a Salvador Dali print, with the image composed of small squares of color.
As digital systems have become more sensitive, the number of pixels in an image has increased, and the quality has become comparable to film. New digital cameras – even on smartphones and tablet PCs – range up to 11 megapixels, and these cameras can produce large prints as good or better than a print made from a large negative. However, such precise cameras are costly.
Film speed is a rating telling how sensitive a particular film is to light, and thus it indicates how much exposure time and light is necessary to make a good image. The current rating, ISO, replaces the ASA and DIN numbers used in the past. The higher the number, the more sensitive to light the film is.
Today many people are using films with a ISO of 200, 400, or even 800 for most of their photos.
Slower film (film with a lower number – 100 or 125) tends to give a better quality of print in terms of color balance and sharpness. These films are wonderful in bright sunlight, but they don’t work well in lower-light settings such as artificially-lit rooms.
The higher speed films (those with a higher number- 400, 800) have the ability to take photos in low light situations. Early high speed films tended to have more contrast and grain. Newer films have improved greatly, but grain can still be an issue if you’re making big prints.
Most non-adjustable cameras are not meant to use high speed films. Check your camera manual for the range of films which you should use for best results.
There are times that you may want a slow film to take photos outdoors to have less grain and contrast – for instance, if you’re shooting pictures of flowers in your garden. Other times you’ll need a faster film to take photos indoors where the light may be poor.
The question of film speed doesn’t apply directly to digital cameras. However, digital photographers still need to understand the concept of film speed, because they can adjust the digital camera to compensate for different conditions such as the amount and type of light – the kind of adjustments a film photographer makes when he chooses the film speed.
With film you must plan ahead and be able to physically change from one roll or type of film to another when conditions change. An advantage of digital photography is that you can adjust the settings and change the sensitivity of your camera from one photo to the next.
Color film comes in negative and positive (transparency) forms. A transparency is what you put in a slide projector; the colors on transparency film are the same as the original subject. In negative film the colors are just the opposite of what they are in the original subject, and you need to have a print made to see the colors clearly.
How you want to use your pictures determines which film is better for you to use. Some people prefer to use transparency film so they can project slides. Other people prefer to shoot negative film and have prints made. Slides are somewhat easier to store because their total volume is less than negatives and prints combined. However, a slide is one-of-a-kind. If you tear a print, you can have another one made from the negative, but once a slide is damaged, the image is gone. Prints can be made from slides, and slides can be made from negatives, but some loss of quality should be expected when transferring images from one medium to another.
For years, many high quality photos intended for reproduction in ads or magazine layouts were done on slides because it provided a better product, usually with a much finer grain pattern. However, today the films are constantly improving and both negative and transparency films work well.
Other uses for transparencies, such as artists’ samples to show their work, are becoming less common as digital media takes over.
Black & white film
Though it’s called black and white, b&w film actually captures an image in an infinite number of shades of gray, along with absolute black and absolute white.
Images presented in black and white have an entirely different sort of impact than those presented in color, and some subjects or moods are better suited to black and white. In addition, true black and white photographs (and negatives) are more lasting than color photographs, if they have been properly processed and are stored in a cool, dry place.
The chemistry for black and white film and paper processing is somewhat simpler and less expensive than color, so for a photographer wishing to set up a home darkroom, black and white has historically been the more practical choice. Because of reduced demand, however, black and white films and photographic papers are no longer widely available. Many are being discontinued.
Many commercial processors today are not creating true black and white photos; they’re producing an image which appears black and white but is made on color paper with color processing techniques (and therefore has the same life expectancy as a color print). Most people will not immediately notice the difference. However you cannot get the same deep, rich blacks with color processing that you can with true black and white.
Expect to pay more for good black and white processing because it requires special care. A lot of places no longer do it at all; some ship the film away, so your prints will take longer to be returned to you. In many cases black and white processing is done by hand rather than with automated machinery, so you may be paying for custom handling.
Many high-end digital cameras have a black and white option in the settings. Or you can shoot digital images in color and then convert them to black and white in the computer.
Instant films have strong advantages for someone who needs a photo right now. They can be fun at parties and on vacations. The main advantage is that you know the photo came out like you wanted; if not, you can immediately take another. But with most instant films there is no negative – if you want more prints, you have to copy the original. Whenever you copy a photo, there is some loss of detail. Also if you forget to coat the prints with the preservative, they will soon start to fade.
Instant films have lost market share as digital media – which is even more immediate and less smelly – have expanded. The main use for instant film now is as a lighting test for commercial photographers.
Creating photographs through electronic files – memory sticks, CDs, hard drives – make storing, sending, and duplicating photos easy. Like instant film, digital files mean you can immediately see whether you captured the photograph you were after, and if not, you can kill the image and re-use the memory space for another photo. You can print photos on your home computer and send them by email.
For many family, vacation, and casual uses, using digital photography is a practical move. However, when you start printing your own pictures, many of the details which the photo lab handled automatically – such things as color balance and red-eye correction – will fall to the individual. Some study and practice is necessary to achieve acceptable results with a home computer and printer.
Digital cameras come with basic software for adjusting and saving photos, but these programs are limited in what they can do. The more a software package lets you adjust an image, the more expensive it is to buy and the more complex it is to learn and use.
The life span of your electronic photos will depend on the quality of your equipment and of your storage media. Some home printers use archival inks which will last fifty years or more, but most do not. Photos produced on non-archival printers may have a life span of just a few years. Many home printers also do not produce a fine enough dot pattern to produce a quality photographic image. Printers good enough to compete with commercial developers are expensive.
Memory sticks (while expensive) can be reused many times, but their life span is not infinite. The life span of CDs is not known, and sometimes new CD units do not accurately read disks burned on an older unit, so updating files to new technology is wise. Hard drives are notoriously prone to failure; always duplicate important images so you’re not relying on one form of storage to preserve them.