Designed and written by Geoff Cable & Gary Crouch from the · Camera manufacturers all have their own form of RAW files (Canon is CR2, Nikon is NEF). RAW files are high quality, retaining

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Designed and written by Geoff Cable & Gary Crouch from the

Image File Formats

Different file formats have different uses and, in this Cheat Sheet, we describe some of the most common file formats used in photography and modern media, including their advantages and disadvantages.

JPEG (JPG) (Joint Photographic Experts Group)

This is one of the most commonly used file formats in photography. Most digital cameras produce images using the JPEG format. It is also widely used for web display photographs and photographic printing. A JPEG file retains all the colour information in an RGB (Red Green Blue) image but is designed to discard data in order to compress file size. However when your camera is set at the highest quality JPEG setting it still retains virtually all of the detail.

Advantages:

Produces smaller file sizes, taking up less space on your memory card and your computer. Faster transfer times. Images are rendered and produced in camera ready for sharing and printing.

Disadvantages:

Lower quality than some other file formats. Some information lost from the capture, limiting the amount of manipulation and processing possibilities in post-production.



RAW

Camera manufacturers all have their own form of RAW files (Canon is CR2, Nikon is NEF). RAW files are high quality, retaining all of the data captured by the cameras sensor. RAW files need to be rendered into an image using some form of processing software (RAW converter). They are like a digital version of an unprocessed film negative that needs developing. Most D.S.L.R.s and sophisticated Compact and Bridge cameras can produce RAW files.

Advantages:

Produces high quality images retaining all of the captured information. Lots of scope for manipulation and processing an image in post-production.

Disadvantages:

Slower transfer times than JPEG. Large file size takes up more space on your computer and memory card. They have to be processed using some form of editing software (RAW converter) adding time to your post-processing workflow.

TIFF (Tagged Image File Format)

This is a file format that is commonly used to transfer information between different applications and computer platforms. It is the format used to move and process an image from Adobe Lightroom into Adobe Photoshop. Most desktop scanners can produce TIFF images. TIFF is a bitmap format that is supported by most image editing and page layout software (unlike some other formats). TIFF is a high quality file format that retains all of the captured information.

Advantages:

High quality. Accepted by many applications. Lots of scope for post processing.

Disadvantages:

Large file size takes up more space on your computer and memory card. Slow transfer times.



DNG (Digital Negative Format)

This is a file format developed by Adobe to address the fact that there isn't a cross industry RAW file format (manufacturers all have their own separate formats). It is available to all manufacturers and is intended as an archival format that is future proof (if for instance a manufacturer goes out of business or software doesn't recognise a specific type of RAW file)

Advantages:

Is recognised by most post processing software. Should always be available in the future.

Disadvantages:

You have to convert your existing RAW files into DNG (using post processing software), which is an extra stage in your work flow.

PSD (Photoshop Document)

This is Photoshop’s standard default format used to work with and retain all the information in a multi layered file. It is non-destructive, meaning that as long as you save the file as a PSD all the information contained in every separate layer will be retained and leaves the original untouched. However if you save a PSD as a different file type (such as a JPEG) or flatten the layers into one, you can no longer edit individual layers or go back to an earlier editing point.

Advantages:

Allows for non-destructive editing of a multi layered document, such as a composite.

Disadvantages:

Multi layered documents can become very large files taking up valuable space on your computer.



PNG (Portable Network Graphics)

The PNG file format was developed as an open file format to replace an old file format called GIF. It is not available in-camera, however is widely used for website images. It allows for a full range of colour and better compression.

A PNG file can have a transparent background and is generally larger and of higher quality than some other formats. Therefore, a PNG is ideal for logos or photo cut-outs on websites because it can have a transparent background and can appear on a webpage as a shape that overlays a coloured background.

Advantages:

PNG is recognised by most post processing software and should always be available in the future. The possibility to store a transparent background is a major advantage of this file format.

Disadvantages:

Although smaller than PSD and RAW file formats, PNG is larger than JPEG and so will have a slower transfer time and take up more space.

HEIF (High Efficiency Image Format)

The HEIF file format is the latest format to be released and has been developed by MPEG, the very same people to develop the newest video compression codec, HEVC (also known as H.265). HEIF has been designed as a direct rival to the JPG format, which has been the first-choice compressed photo file format for over 25 years and is widely supported across all manufacturers of software and hardware, and it stands a good chance at succeeding at taking over JPG’s top spot position. Apple are one of the first companies to embrace the use of the HEIF format after announcing that, from IOS 11, all photos taken with their devices, including iPhones and iPads, will be in HEIF format by default and that JPG would no longer be supported.

Based on this you can bet that HEIF will become a major player in the future of image formats.

Advantages:

HEIF image files are approximately half the file size of JPG image files, allowing twice as many photographs to be stored. As an example, an iPhone 7 with 128GB storage can store around 50,000 JPG images at 12 megapixels, however this quantity doubles to around 100,000 when using the HEIF format, with apparently no loss in image quality.



Disadvantages: The HEIF file format is not currently very widely supported through the high number of software and hardware platforms. Anything that displays images will need to support the new format and the extent of this is not yet fully known. Web browsers (Chrome, Firefox, Internet Explorer etc.), editing software such as Adobe’s Photoshop and Lightroom as well as video editing software, digital ‘point and shoot’ camera’s as well as DSLR’s, digital photo frames, the list goes on and on and on. Anything that displays images is affected. This is certainly one to watch for the future. To check or reset the file format you are using with your camera go to the cameras menu, it is usually listed under Quality. There you can set the file type and also the amount of detail required (for instance RAW or JPEG and Low, Medium or High quality). If you want to set JPEG for speed and RAW for post processing quality many cameras offer an option to shoot both at the same time, however this will use up a lot of memory on your data card and computer.

We hope you found this cheat sheet useful, visit our web site at www.gc2photoclub.com for more and sign up to our newsletter to be kept up to date with the latest cheat sheets, tutorials and information. Bye for now Geoff and Gary

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Designed and written by Geoff Cable & Gary Crouch from the · Camera manufacturers all have their own form of RAW files (Canon is CR2, Nikon is NEF). RAW files are high quality, retaining