Adobe’s Photoshop software is a very powerful image editing program that is by far the market leader for editing image files. I use Photoshop extensively when creating, and editing images for the web sites that I design. Almost all professional photographers and printers also use Photoshop to create all of the wonderful images that appear in magazines, billboards, and even on television. I am not the best artist in the world, but with Photoshop I have enough power to create brilliant images with tools that are built-in to the software. The coolest thing about Photoshop is that even as powerful as it is out of the box, there are many different plug-ins to make Photoshop even more powerful. The Photoshop plug-ins can be grouped into a few major categories which include 3D, color management, digital asset management, photographic, retouching, and special effects.
In the camera world there are dozens of formats, each format has something unique and some are more common than others. DNG (Digital Negative) Camera companies have introduced many different, and frequently changing, raw file formats. For example, one source states that there are over 140 RAW formats with more coming-some of them specific to a single camera model. On top of this, manufacturers are often pointlessly secretive about their specifications so there are almost always RAW files your software can’t read-at least until someone reverse engineers the formats so they can support them. This lag time and inconvenience can be laid at the doorstep of the camera companies. These proprietary RAW files are at risk over time since companies come and go and interest waxes and wanes. One solution to this growing problem is a new Adobe format called the Digital Negative (.DNG). This publicly defined and openly shared format for RAW files is an attempt to ensure that you will be able to access your image files in the future. If your camera doesn’t capture RAW images in this format, you can convert them to DNG using a program such as Photoshop or Lightroom. When you do so, you can even choose to store the original RAW image inside its DNG file so you can extract it at some future date should you need it. The DNG format is supported by Photoshop and other Adobe products, some other software companies, and a number of camera companies. As with all things in computing, only time will tell if the format becomes widely accepted or gradually fades away.
When the image is then opened and displayed by any application, the compression process is reversed more or less depending on which form of compression was used lossless or lossy. Lossless compression compresses an image so when it is uncompressed, as it is when you open it, its image quality matches the original source nothing is lost. Although lossless compression sounds ideal, it doesn’t provide much compression so files remain quite large. For this reason, lossless compression is only used by the highest quality image formats-namely TIFF and RAW.
RAW files are quite large. If you use this format a great deal you will need more storage space in the camera, and computer processing times may be slightly longer. When shooting images, you may have to wait longer between shots because the buffer gets filled more quickly and the camera is tied up longer processing the last image you took, and moving it from the buffer to the memory card. Since RAW images aren’t processed in the camera, you have to process them on the computer and export them in a usable format when you want to e-mail them, post them on a Web site, print them, or import them into another program to create a slide show or publication. When you are done shooting for the day, there is still work to do. Since each camera company has defined its own proprietary RAW format, many operating systems and even photo-editing programs are unable to recognize some or all of these files. For this reason camera manufacturers always supply a program to process RAW images along with their cameras.
As you take pictures, your camera automatically creates and names subfolders within the DCIM folder to hold them (like placing manila folders in a hanging folder). The first three characters in a folder’s name, called the directory number, are numbers between 100 and 999. The next five characters are known as free characters and can be any uppercase alphanumeric characters chosen by the camera manufacturer. When a new folder is created, as one is when the current folder is full, it is given a number one digit higher than the previous folder. Some cameras allow you to create and name your own folders, or select among folders the camera creates. This lets you route new images into a specific folder and also play back images from just one folder rather than the entire card.
Extensions play another important role. An extension can be associated with a program on your system so if you double-click a file, the associated program opens and then it in turn opens the file you clicked. Also, when you use an application program’s File > Open command it often lists only those files with extensions that it can open. (You can list other file types but it usually requires an additional step or two.) If you change the extension, your system may no longer know what to do with the file.
Exif (Exchangeable Image File Format) is a specification that spells out how information about a JPEG image is stored in the same file as the image. This information, including a thumbnail image, describes the camera settings at the time the picture was taken, and even the image’s location if the camera supports GPS (Global Positioning System). Digital cameras record this information as metadata in an area of the image file called the header. This information isn’t just for managing images, it can also be used by some printers to give you better results. Basically, any camera control set to auto at the time the image was taken can be manipulated by the printer or other device to improve results. Those set to one of the camera’s manual choices is considered to be a deliberate choice and is not manipulated.
