Digital photography, as opposed to film photography, uses electronic devices to record and capture the image as binary data. This facilitates storage and editing of the images on personal computers, and also the ability to show and delete unsuccessful images immediately on the camera or software itself.
Digital cameras now outsell film cameras and include features that are not found in film cameras such as the ability to shoot video and record audio. Some other devices, such as mobile phones, now include digital photography features.
Sensors and storage
Sensors read the intensity of light as filtered through different color filters, and digital memory devices store the digital image information, either as RGB color space or as raw data.
There are two main types of sensors:
- charge-coupled device (CCD) – photocharge is shifted to a central charge-to-voltage converter
- CMOS sensors ("Active pixel sensor")
Nearly all digital cameras now use solid state flash memory, but for a time floppy disks were used in early digital cameras such as the Sony Mavica.
Comparison with film cameras
Advantages of consumer digital cameras
The advantages of digital photography over traditional film include:
- Instant review of pictures, with no wait for the film to be developed: if there's a problem with a picture, the photographer can immediately correct the problem and take another picture.
- Only successful pictures need to be printed. This allows one to take numerous shots of the same scene with slightly different settings, then choose the best one. This review and revise process is impossible with traditional film because such film requires time and equipment to develop.
- Minimal ongoing costs for those wishing to capture hundreds of photographs for digital uses, such as computer storage and e-mailing, but not printing.
- If one already owns a newer computer, permanent storage on digital media is considerably cheaper than film.
- Images may be copied from one medium to another without any degradation.
- Pictures do not need to be scanned before viewing them on a computer.
- Ability to print your own pictures using a computer and consumer-grade printer.
- Ability to print your own pictures using printers that can communicate directly with the camera, or its memory card, for computer-less printing.
- Digital cameras can be much smaller than film cameras of equivalent quality.
- Ability to embed metadata within the image file, such as the time and date of the photograph, model of the camera, shutter speed, flash use, film speed, and other similar items, to aid in the reviewing and sorting of photographs. Film cameras have limited ability to handle metadata, though many film cameras can "imprint" a date over a picture by exposing the film to an internal LED array (or other device) which displays the date.
- In camera electronics allow many features and effects which would be impossible with film.
- Ability to capture and store hundreds of photographs on the same media device within the digital camera; by contrast, a film camera would require regular changing of film (typically after every 24 or 36 shots).
- Many digital cameras now include an AV-out function (and cable) to allow the reviewing of photographs to an audience using a television.
- Digital photography enables you to experiment with the camera settings, different styles of images can be tried out, learnt from and techniques improved all without the expense of film processing.
- Digital anti-shake tools allow taking sharp hand-held pictures where previously a tripod was required
- You effectively have a home colour darkroom where you can do much with an image.
- You bypass the photo labs.
- You can change the ISO values easily in the middle of shooting, for example when the weather changes from bright sunlight to cloudy. In film it means you have to rewind the film, unload it and load the new film with desired ISO value, and this is obviously not as convenient.
Advantages of professional digital cameras
- Immediate image review and deletion is possible; lighting and composition can be assessed immediately which ultimately conserves storage space.
- The ability to shoot in RAW format (images that contain tagged data directly from the sensor). However, as of this writing, there are a number of proprietary RAW formats, some of which require specific software to manipulate.
- Faster workflow: Management (colour and file), manipulation and printing tools are more versatile than conventional film processes. However, batch processing of RAW files can be time consuming, even on a fast computer.
- Digital manipulation: A digital image can be modified and manipulated much easier and faster than with traditional negative and print methods. The digital image to the right was captured in RAW format, processed and output in 3 different ways from the source RAW file, then merged and further processed for color saturation and other special effects to produce a more dramatic result than was originally captured with the RAW image.
Recent manufacturers such as Nikon and Canon have promoted the adoption of digital Single-lens reflex cameras (dSLRs) by photojournalists. Images captured at 2+ megapixels are deemed to be of sufficient quality for small images in newspaper or magazine reproduction. Six to 14 megapixel images, found in modern digital SLRs, when combined with high-end lenses, can approximate the detail of film prints taken with 35 mm film based SLRs, and the latest 16 megapixel models can produce astoundingly detailed images which are believed to be better than 35mm film images and the majority of medium format cameras.[3]
Disadvantages of digital cameras
- Power consumption (battery usage) greatly exceeds that of film cameras.
- Digital images are less trusted as evidence than film images.[citation needed] Some manufacturers attempt to soften this disadvantage by providing methods to show whether their camera images have been altered.[citation needed]
- Digital sensors often have less dynamic range than color print film. However, some newer CCDs such as Fuji's Super CCD, which combines diodes of different sensitivity, have addressed this problem.
- Multi-coloured image noise is evident in some pictures.
For most consumers in prosperous countries such as the United States and Western Europe, the advantages of digital cameras outweigh their disadvantages. However, the professional photography community is split on the issue. Much of the post-shooting work once done in the past by a photo lab is now done by the photographer himself. Problems some professional photographers have voiced include: editing and post-processing of RAW files can take longer than 35mm film, downloading a large number of images to a computer can take away from valuable shooting time, shooting in remote sites requires the photographer to carry a number of batteries and add to the load she/he must carry, all cameras break from time to time — film cameras can often be fixed on the spot but digital cameras often can not.As time passes, it is expected that more professional photographers will switch to digital.
