file formats

Digital File Formats ...

• JPEG…
• TIFF…
• RAW…
• DNG…

JPEG… Joint Photographic Experts Group…

Your digital camera usually offers various sizes of JPEG images under various guises and, headings like Large, Fine, Standard, Medium and Small for example… This allows the photographer to choose how much compression they want to impart to the image, enabling the file size to be reduced to as little as 5% of the original image size…

Some people are confused when they see the options given in the cameras menu of large, medium and small or fine, standard and low especially if they have read the manual and it gives the actual image sizes that correspond to those settings… Take the Canon 10D for instance, large is 3072 x 2048 pixels, medium is 2048 x 1360 pixels and small is 1536 x 1024 pixels… Does this mean only part of the sensor is used to capture the image when medium or small are chosen? The answer is no, all it means is the algorithms of the cameras processor chooses which data to throw away while compacting the information into a smaller image size… The information that is thrown away is usually in the mid tone range making the image appear sharper when displayed in smaller prints but at the loss of gradation between shades, which becomes obvious if you need larger prints… So if you need large prints use the finest JPEG your camera will offer, if you only want small prints or to view the images on the computer medium or small will do…

JPEG is known as a cooked file format, which means the image is actually processed in the camera therefore at the mercy of the individual cameras algorithms… The sharpness, saturation, white balance etcetera are all imbedded and converted into an image file by the cameras processor…

Note: JPEG is the most commonly supported photographic file type for the web and for commercial digital printing…

TIFF…Tagged Image File Format…

This is a lossless format retaining all the original information recorded on the sensor therefore creates large files than JPEG’s when processed by the camera… TIFF is also known as a cooked file because all the data conversion is done in the camera by its built in software…This file format or your digital editing softwares own lossless file format is the one to use when you wish to alter an image and resave it for further work because it retains all the pixels of the original image…

Note: This is one of the most commonly supported formats for storing bit-mapped images in computers that can be read by both PC’s & Mac’s

RAW…

This is actually unprocessed data not a cooked image and RAW files require a special software program that comes with the camera to decode the files or a third part software program like Adobe Photoshop or RawShooter… Most camera manufacturers have their own version of RAW images… If you are saving your images as raw files the camera creates a data file and metadata file that contains all of the camera settings (metadata is data on the data) including the sharpening level, contrast, saturation settings, colour temperature / white balance, lens, aperture, shutter speed and so on and so forth, the amount of information stored depending on the camera…

The image is not cooked by these settings but it’s tagged on to the raw data and can be changed before the image is actually processed by the external digital software... This has the advantage of being able to use a more powerful set of algorithms because It is not confined to memory space in the camera… You can change the exposure value if the RAW data preview is under or over exposed, you can change the sharpness, saturation, shadows, brightness and contrast etcetera before the data is converted into an image … RAW also has the advantage of not being able to be overwritten by accident as the images when saved can be saved as jpeg, tiff for printing or whatever file type your software will allow...

DNG…

Now the clever people at Adobe have come up with the Digital NeGative file format… They have a free program called Adobe DNG, which will convert most camera manufacturers own RAW formats in to a standard digital negative file format called DNG… This converts the individual camera manufacturer’s information to one that can be read by Photoshop, enabling editors etc to open RAW files from users of most makes and models of digital cameras… This conversion still retains all the detail and RAW options offered by the original file but reduce its file size… RawShooter will also read DNG files

	Freelance Photographer Seeing things differently A taker of Photographs - A creator of images
Kennymc.com

Digital File Formats ... • JPEG… • TIFF… • RAW… • DNG… JPEG… Joint Photographic Experts Group… Your digital camera usually offers various sizes of JPEG images under various guises and, headings like Large, Fine, Standard, Medium and Small for example… This allows the photographer to choose how much compression they want to impart to the image, enabling the file size to be reduced to as little as 5% of the original image size… Some people are confused when they see the options given in the cameras menu of large, medium and small or fine, standard and low especially if they have read the manual and it gives the actual image sizes that correspond to those settings… Take the Canon 10D for instance, large is 3072 x 2048 pixels, medium is 2048 x 1360 pixels and small is 1536 x 1024 pixels… Does this mean only part of the sensor is used to capture the image when medium or small are chosen? The answer is no, all it means is the algorithms of the cameras processor chooses which data to throw away while compacting the information into a smaller image size… The information that is thrown away is usually in the mid tone range making the image appear sharper when displayed in smaller prints but at the loss of gradation between shades, which becomes obvious if you need larger prints… So if you need large prints use the finest JPEG your camera will offer, if you only want small prints or to view the images on the computer medium or small will do… JPEG is known as a cooked file format, which means the image is actually processed in the camera therefore at the mercy of the individual cameras algorithms… The sharpness, saturation, white balance etcetera are all imbedded and converted into an image file by the cameras processor… Note: JPEG is the most commonly supported photographic file type for the web and for commercial digital printing… TIFF…Tagged Image File Format… This is a lossless format retaining all the original information recorded on the sensor therefore creates large files than JPEG’s when processed by the camera… TIFF is also known as a cooked file because all the data conversion is done in the camera by its built in software…This file format or your digital editing softwares own lossless file format is the one to use when you wish to alter an image and resave it for further work because it retains all the pixels of the original image… Note: This is one of the most commonly supported formats for storing bit-mapped images in computers that can be read by both PC’s & Mac’s RAW… This is actually unprocessed data not a cooked image and RAW files require a special software program that comes with the camera to decode the files or a third part software program like Adobe Photoshop or RawShooter… Most camera manufacturers have their own version of RAW images… If you are saving your images as raw files the camera creates a data file and metadata file that contains all of the camera settings (metadata is data on the data) including the sharpening level, contrast, saturation settings, colour temperature / white balance, lens, aperture, shutter speed and so on and so forth, the amount of information stored depending on the camera… The image is not cooked by these settings but it’s tagged on to the raw data and can be changed before the image is actually processed by the external digital software... This has the advantage of being able to use a more powerful set of algorithms because It is not confined to memory space in the camera… You can change the exposure value if the RAW data preview is under or over exposed, you can change the sharpness, saturation, shadows, brightness and contrast etcetera before the data is converted into an image … RAW also has the advantage of not being able to be overwritten by accident as the images when saved can be saved as jpeg, tiff for printing or whatever file type your software will allow... DNG… Now the clever people at Adobe have come up with the Digital NeGative file format… They have a free program called Adobe DNG, which will convert most camera manufacturers own RAW formats in to a standard digital negative file format called DNG… This converts the individual camera manufacturer’s information to one that can be read by Photoshop, enabling editors etc to open RAW files from users of most makes and models of digital cameras… This conversion still retains all the detail and RAW options offered by the original file but reduce its file size… RawShooter will also read DNG files


Designed by Ken McDonald	All Copyrights Reserved