Expert digital photographers are raving about RAW images. Instead of setting their cameras to save their photos as JPEG or TIFF formatted...
Expert digital photographers are raving about RAW images.
Instead of setting their cameras to save their photos as JPEG or TIFF formatted files, they save them as RAW files.
Why? Because RAW images are uncompressed and unformatted — just the data captured by the image sensor and saved in the camera.
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By comparison, the most commonly used JPEG format involves some processing of the image, including compression and loss of data.
Greater color depth
RAW images also have greater color depth, which means more colors and smoother gradation of tones.
For example, JPEG images have 8 bits per color channel, totaling 256 tones for each of the three RGB (red, green and blue light) color channels, while RAW images have 16 bits per color channel, totaling 4,096 tones for each color channel.
The main disadvantage of saving images in RAW is that files are much larger than JPEG files. A RAW image file is about the same size as the pixel count of the camera. In a 6-megapixel camera, for instance, a RAW file is about 6 megabytes.
By contrast, a JPEG file is 1 to 2 MB, and a TIFF file is about 18 MB.
Time is also an issue. Because the RAW file is so large, it takes longer (than a JPEG image) to save in the camera, so the delay between shots can be significantly longer.
Time is also an issue when transferring RAW images from the camera to a computer. Typically, it’s a two-step process to upload RAW images to the camera’s proprietary software for preliminary editing and conversion to TIFF or other format for further refinements.
Alternatively, Adobe Photoshop, Photoshop Elements 3 and iPhoto 5, for example, can import RAW images from some cameras, reducing the editing and conversion process to one step.
OK, I’m thinking, why not try it? I’ll save images in RAW, go through the editing and printing processes, then report back.
Maybe my experience will help you decide if you want to try it, too.
I switch the storage setting on the Olympus C-7000 compact camera I’m using from HQ (high-quality) JPEG to RAW, and instantly the warning about storage space rings true.
My 512 MB memory card, which can hold more than 400 images in HQ JPEG, can hold only 48 in RAW.
When I press the shutter, it takes at least 20 seconds to save before I can shoot the next picture.
An hour later, the card is full, and I’m eager to see the results.
At home, I connect the camera to the computer, open iPhoto, start to import the RAW images and quickly discover iPhoto can’t read the image files.
I check the user manual, Help menu and finally go to Apple’s support Web site to discover this camera isn’t on the list of compatible cameras (www.apple.com/macosx/upgrade/cameras.html).
So, I open Photoshop Elements and start to import the RAW images, but it also refuses.
Again, I end up at the support site, and again discover this good-quality 2004 camera is not on the compatibility list. (www.adobe.com/products/photoshop/cameraraw.html).
Now I’m frustrated and berating myself for assuming most popular cameras would be compatible.
Because I can’t use any of my installed photo software to import RAW, I install the Olympus software that came with the camera and import the images.
That works, but it does take time to learn new photo-editing software, and I’d much rather use familiar tools I know work well.
Later, using a camera on iPhoto’s RAW compatible list, I import the RAW images directly to iPhoto and edit them before converting to TIFF.
I convert to TIFF (rather than JPEG) because that format permits me to edit and save repeatedly without degrading the image.
I’m delighted by how much the RAW images (shot indoors) can be improved by using the exposure and sharpening tools.
However, iPhoto automatically saves the edited RAW images as JPEG files, so I have to export them to my hard drive as TIFF files then move them back into the iPhoto Library.
Next, I import another card full of photos to Elements, where I can do all the image processing and save the files in TIFF format in case I want to do more editing later.
Finally, I print some of the images. They look better than similar shots I’ve saved, edited and printed in HQ JPEG format.
Being able to correct underexposed shots and having a wider tonal range does make a difference.
If your camera can save in RAW and you don’t mind spending a little extra time to get better pictures, go ahead and try it.