A large number of readers will probably be using a digital camera to capture their photographs and will find themselves presented with a choice between capturing in JPEG or raw mode. Whichever way you look at it, all images are captured as raw data and the raw information has to be converted at some stage into an RGB pixel image that Photoshop can work with.
All digital cameras have an on-board processor that will interpret the raw capture data and render it as a pixel image. This process will usually take into account the camera white balance settings, along with any other custom settings that dictate things like sharpness, levels clipping, color mode and noise reduction, etc. If you shoot using the camera’s JPEG mode, you will be letting the camera decide on-the-fly how the conversion is to be carried out and the capture file output will be a fully-rendered pixel image saved using the JPEG format. If your camera output is a JPEG or a TIFF image, there is not much else you need to know about raw data right now and you can get straight down to the business of editing your images in Photoshop.
When you edit a pixel image, your starting point will always be a fixed pixel original. There are a number of ways in Photoshop that you can edit such a picture nondestructively, by using layers and adjustment layers or Smart Objects even. But your options will always be constrained by the nature of the original pixel image. Plus, adding more layers can greatly increase the overall file size.
But if you choose to shoot in raw mode, the possibilities are endless. The raw data is just that: it is the raw image data that was captured by the sensor and the only thing that is fixed in the raw file is the ISO setting that was used to capture the photograph. The raw image is therefore like a digital negative just waiting to be developed and you can have complete control over how the image is processed, whereas if you shoot using the JPEG mode, you will be letting the camera make all the raw process editing decisions for you.
The Adobe Camera Raw plug-in has evolved over several versions of Photoshop now and provides a lot of powerful features with which to process raw image files from selected cameras and convert them into pixel images that Photoshop can work with. The Camera Raw plug-in provides true non-destructive image editing because the raw file is never modified. The edits you make via the Camera Raw plug-in are effectively instruction edits that are saved as metadata to a central database and can also be saved locally to XMP sidecar files (or in the case of DNG and other non-proprietary files saved to the file itself).
This marks a radical shift in direction from the pixel-based image editing that Photoshop built its reputation on. If I want to preserve all the information from one of my Canon EOS 1Ds Mk II camera captures as a 16-bit TIFF file, the file would end up being almost 100 MB in size (and that is before adding extra layers). A raw master file by comparison will be no bigger than 15 MB (less if converted to DNG) and every time I edit the raw file, the edit instructions can be stored in just a few kilobytes of extra data. Raw image processing is now just as important as pixel imaging (some would argue it is even more so) and it is not just in the realm of Photoshop. There are now many other programs that will allow you to edit almost exclusively with raw images. The new Adobe Photoshop Lightroom program will let you edit and manage both raw and non-raw images. Capture One is another raw image processor that is popular with photographers and Apple’s Aperture which, like Lightroom, is primarily a workflow
tool for digital photographers.
How do we describe this raw image processing? Do we call it raw editing, instruction set editing, metadata editing? Whatever it is called, Raw offers photographers a greater level of control over how they process their images and encourages us to keep our images in their raw state longer, before it is necessary to render them as pixel images to be worked on in Photoshop.
All digital cameras have an on-board processor that will interpret the raw capture data and render it as a pixel image. This process will usually take into account the camera white balance settings, along with any other custom settings that dictate things like sharpness, levels clipping, color mode and noise reduction, etc. If you shoot using the camera’s JPEG mode, you will be letting the camera decide on-the-fly how the conversion is to be carried out and the capture file output will be a fully-rendered pixel image saved using the JPEG format. If your camera output is a JPEG or a TIFF image, there is not much else you need to know about raw data right now and you can get straight down to the business of editing your images in Photoshop.
When you edit a pixel image, your starting point will always be a fixed pixel original. There are a number of ways in Photoshop that you can edit such a picture nondestructively, by using layers and adjustment layers or Smart Objects even. But your options will always be constrained by the nature of the original pixel image. Plus, adding more layers can greatly increase the overall file size.
But if you choose to shoot in raw mode, the possibilities are endless. The raw data is just that: it is the raw image data that was captured by the sensor and the only thing that is fixed in the raw file is the ISO setting that was used to capture the photograph. The raw image is therefore like a digital negative just waiting to be developed and you can have complete control over how the image is processed, whereas if you shoot using the JPEG mode, you will be letting the camera make all the raw process editing decisions for you.
The Adobe Camera Raw plug-in has evolved over several versions of Photoshop now and provides a lot of powerful features with which to process raw image files from selected cameras and convert them into pixel images that Photoshop can work with. The Camera Raw plug-in provides true non-destructive image editing because the raw file is never modified. The edits you make via the Camera Raw plug-in are effectively instruction edits that are saved as metadata to a central database and can also be saved locally to XMP sidecar files (or in the case of DNG and other non-proprietary files saved to the file itself).
This marks a radical shift in direction from the pixel-based image editing that Photoshop built its reputation on. If I want to preserve all the information from one of my Canon EOS 1Ds Mk II camera captures as a 16-bit TIFF file, the file would end up being almost 100 MB in size (and that is before adding extra layers). A raw master file by comparison will be no bigger than 15 MB (less if converted to DNG) and every time I edit the raw file, the edit instructions can be stored in just a few kilobytes of extra data. Raw image processing is now just as important as pixel imaging (some would argue it is even more so) and it is not just in the realm of Photoshop. There are now many other programs that will allow you to edit almost exclusively with raw images. The new Adobe Photoshop Lightroom program will let you edit and manage both raw and non-raw images. Capture One is another raw image processor that is popular with photographers and Apple’s Aperture which, like Lightroom, is primarily a workflow
tool for digital photographers.
How do we describe this raw image processing? Do we call it raw editing, instruction set editing, metadata editing? Whatever it is called, Raw offers photographers a greater level of control over how they process their images and encourages us to keep our images in their raw state longer, before it is necessary to render them as pixel images to be worked on in Photoshop.
Converting Raw Data into Pixels
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