Introduction 
 Cameras 
 Equipment 
 Using cameras 
 Software 
 File Types 
 Resolution 
 Image Structure 
 Workflow 
 Raw 
 Printing 
RAW files

Overview:
When a digital camera captures an image, it has to be saved. The file is saved in a format which is recognisable to computer software which then enables that software to open the file.

Jpegs:
All digital cameras will save files in .jpg format. There are many reasons for this. Jpeg files are widely used and understood by programs and so can be opened on any computer without specialist software. They are a compressed file which mean that an image when saved will typically take up about one eighth of the space that an uncompressed file would take. This means that you can store eight times the number of pictures on you camera. In saving the file as .jpg all the setting on your camera are used in the writing of the file. If you have set black/white mode the image will be black/white. If you set the white light balance or vivid colour, sharpening, or any other parameters they will become part of that file. They can not be undone.
Because the image is compressed some of the original image information captured is 'thrown away' as the file is saved.

 

RAW:
A RAW file will not compress the information, and although it records the details as taken, it saves the information captured without applying any parameters, you then have the option of using Raw conversion software to reset the colour, tonal range and to a degree exposure. Because the file is not compressed all the information captured is saved, nothing is discarded. By allowing you to make decisions about the file parameters after taking you have much greater flexibility. A greater tonal range is possible with a RAW file. There is no single RAW format, rather it is a generic name that describes a a family of file formats. Most camera manufactures have their own formats, some have more than one. This means that there are over 12 commonly used file types - all called 'RAW'. To open these files you need a program that will understand and process them enabling them to be saved as one of the more common file types.

Option 1
The camera manufactures will provide software for their camera, which will usual not open files from other cameras. The quality and usability of this software ranges from reasonable to almost useless. Some manufacturers will charge you for this software.

Option 2:
This involves using 'third party software' written by someone other than the camera manufacturer to open you files. Some are 'stand alone' allowing you to open, adjust and then save the file before re-opening it in a manipulation program (eg. Photoshop). Other provide a plug in to Photoshop or other programs.

Option 3:
Two programs will open most RAW files directly. Both Photoshop and Gimp will open just about all RAW files in an addition interface before loading them into the main program. Although Photoshop offers some extra options, Gimp with Ufraw is an excellent option. Profiles for your camera can be loaded for optimum compatibility. In the raw-converter I adjust the white balance and exposure to ensure that the highlights are not 'clipped' and leave everything else till the next stage.

Photoshop and Gimp open the raw image in an additional 'front end' to the programme, once converted they are transferred into the main program and you can work on them as you would any other image. My method is to first carry out any resizing, cropping and transforming. Next I make colour and contrast adjustments (usually in levels or curves) and finally sharpen the image if required. Individually adjusted images should then be saved into the appropriate folder. Saving files as .tif will maintain the quality, but for photographic lab printing you will need to save as .jpg.