As the recent ‘History of the Camera’ infographic revealed, digital technology has changed photography forever. Digital cameras have revolutionised the whole photography process, from taking the pictures to developing them. Digital technology has also revolutionised the way in which images are stored and distributed. File size, compression and colour profile conversions are all relatively new things for photographers to concern themselves with. This article details a few considerations for digital photography and using images online.
One of the most important distinctions between photography for print and online is the CMYK/RGB distinction. All computer monitors use RGB, while for years the print industry has relied on CMYK. RGB actually has more colours than CMYK, so CMYK to RGB conversion is relatively straight forward.
Accurate colour is hard to achieve online, as each computer monitor uses device-dependent colour. That doesn’t mean you shouldn’t attempt to accurately match colour online. In terms of creating images, the best thing you can do is ensure that your own monitor is as accurate as possible. Digital photographers should be using high-definition monitors that are calibrated regularly.
Some monitors have a colour correct or calibrate feature which will help to match colour standards. It is possible to calibrate a monitor by eye, which may seem like an easy and economical solution, but it is also highly inaccurate. This may be acceptable, but for professional photography, such as product photography for digital catalogue production for example, accurate colour matching is crucial.
Size and resolution
Size and resolution are other important aspects of digital photography, as resizing images within HTML code can result in some highly unfavourable results. Most digital cameras have many options regarding the size and resolution of captured images. Size is the actual dimensions of the image, as in its width and height, while resolution refers to the density of information or pixels.
When using images online there are two things to consider; quality and load time. High quality images will take a long time to load, hogging user’s bandwidth and impeding a website’s performance. Small images will load quickly but will inevitably be lacking in quality. While it’s easy to reduce the quality of images for the web, it’s impossible to “scale up” an image once the resolution or size has been reduced. Keeping copies of an image in the highest possible size and resolution is best practice.
There are many different types of image file formats that can be used to publish images digitally. For web, the most common are JPEG, GIF and PNG. Each file format has a different type of compression, which is an algorithm used to reduce the size of the file. Each also has different colour profiles, so the correct file type to choose depends on the specific context.
- GIF stands for Graphics Interchange Format, and the format has been used since 1987, particularly on the World Wide Web. A lack of colours makes GIF files unsuitable for large colour photographs and designs, but well suited to smaller, simpler images such as logos and other graphics that have large areas of solid colour.
- PNG or Portable Network Graphics files support lossless data compression. The file type was designed as an improvement on the Graphics Interchange Format (GIF). PNG was designed for World Wide Web images, and as such does not support the CMYK colour profiles traditionally used for print designs and photography
- JPEG, named after the Joint Photographic Experts Group, is the most common image file type on the web, and is used by most digital cameras. The great thing about JPEGs is that the degree of compression they use on an image can be adjusted, so you can more finely weigh-up storage size and image quality.