- Photo File Format types introduced
Photo File Format types introduced
With numerous different photo files and format files the aim of this article is to explain their role in photography in the digital realm.
Each photo file format has a different purpose and with each file comes a positive and a negative attribute.
Read on to obtain a better understanding of photo files, and which is the right one for you and your purpose. You will probably identify different types which you could utilise at different points in yourworkflow from shooting editing and output, depending on your setup, what you shoot and where it gets printed or published and what its used for.
This is not an exhaustive list but neverthelss should provide a bit of basic information for those who hear these terms but do not know what they mean.
What is compression?
With file sizes ever increasing we need to adapt and harness the relevant information and on some occasions dispose of the unwanted. By disposing of our unwanted information (i.e. compressing our images) we can keep our digital files at a manageable size, appropriate for their various uses. For example, a photo for a website needn’t be larger than 1 megabyte, if it was larger than this it would take an age to load up. By compressing the file you dispose of the duplicated information and patterns within the file. However if you compressed a photo for web use and attempted to print it out you would notice severe blocking on colours and distortion of rounded edges.
What is Lossy?
Lossless compression algorithms do not discard any information; instead it will represent an image in a more efficient manner. This can be found in replacing recurring patterns with simplified abbreviations, this will reduce file sizes without a loss in image quality.
Lossy will commonly replace complicated colour or detailing information at a lower resolution then the original image. This is witnessed by subtle tonal changes in an image turning into simple monotone blocks of colour or worse still curved surfaces turning in to block formations simulating a curve.
What is a Jpeg? : (Joint Photographic Experts Group)
A Jpeg is a universal photo format file that is recognised by most of today’s digital devices. This file is currently the most widely used digital file throughout the world, the benefit of this is the ability to capture an image load it onto your computer and publish this in an email or on a website. The key with a Jpeg file is that it is suitably small for use in almost any application achieving a fantastic compression ratio while maintaining good image quality (depending on the strength of compression applied).
What is a RAW File?
RAW files in short are uncompressed, loss-less files where all the original information will be maintained throughout the life of the file, regardless of how many times the file is opened. RAW files come in many different file formats .CR2 (canon), .NEF (Nikon), ect... As there are so many different versions of these RAW files you will require specific types of computer based software to read the file.
The advantages of using RAW files are extraordinary.
What is a DNG?
DNG or Digital Negative files are universal RAW files. With a large variety of manufacturers changing their RAW files so frequently it is difficult to ensure a RAW file is optimised over multiple computers without the implementation of dozens of different software programs. A DNG file offers the user the flexibility of using almost any software with none of the loss in quality or post-production options.
What is a TIFF File?
TIFF standing for Tagged Image File Format, supremely flexible TIFF files are available in compressed and uncompressed options when being saved. Used almost exclusively as an uncompressed file sizes are noticeably higher then Jpeg, but image quality is 100% retained and TIFF’s are almost universally accepted by computers. This can also offer one crucial benefit in the long term, should manufacturers cease to support their older RAW formats without the appropriate software your files will become increasingly hard to access. Converting your RAW files to DNG files will ensure your images are accessible into the distance future.
What is a GIF?
GIF files are used primarily for web work, offering a strict use of 256 colours. This is achieved by employing algorithms to modify colours close to its accepted shades and thus reducing the information needed and the file size. GIF also uses one other function to compress files, by replacing repeated information such as “Red, Red, Red, Red,” an algorithm will simple input “3 Red”. GIF’s are one of the highest forms of compression when using colour rich images, but for graphics with less than 256 colours e.g. logos, GIF files are lossless.
What is a PSD?
PSD files are proprietary formats created and used by Adobe for their use within Adobe Photoshop, these files retain all the editing powers that have been applied previously and will allow further editing to be applied in the future. This offers users the benefit of reverting their edited work to its original stage or even part of the way through their edited path. This can be useful if you are mid way through editing an image and need to save your work, offering you to ability to start where you previously left off. However it is strongly advisable to save your work in a universal format when you are satisfied you have completed your image thus retaining the option to view your files on different computers without the need for the specific software.
Why should I use RAW?
RAW files require extra software due to the amount of information they contain and the potential within each file. Unlike any other image file RAW files are able to retain a noticeable broader range of information. As such should you encounter an image that is too dark, there is sufficient remaining information to re-enter the data post capture. This re-entering of information means that as opposed to brightening your image and turning the black areas into grey you are shifting the entire exposure. Raw files are currently offering 3 stops exposure latitude in their recovery of information. Teamed with this there are numerous other modifications such as white balance adjustment that can be made without deformation or loss of detail, this can be done by utilising the extra data contained within the file.
Once you have edited a RAW file you will notice that there is an identically named .XMP or sidecar file, this is because editing RAW files is a non-destructive process, these XMP files contain all of your modification data in and it is important to keep these as safe as the original RAW files. Should you delete these files or neglect to transfer these with the RAW file your image will appear as it was originally recorded with no modifications.
Are there any downsides to using RAW?
In short, there only a few downsides with RAW files one is the compatibility issues requiring you to have the appropriate software installed on your computer. The other downside is the noticeably larger file size occupying more space on your camera’s memory card. Due to this it offers you the opportunity to capture fewer images while out taking pictures. But bearing in mind the ever increasing storage drives and reducing costs of digital data storage this is only a minor problem.