I need some advice about using RAW capture mode. I have just started shooting in RAW mode but after some research on the Internet, I still have some questions about RAW. Why won’t Photoshop CS3 or Elements 7 open and convert the RAW files from my EOS T1i? Also, when using the Canon DPP software, should I save the photos to an 8-bit Tif or a 16-bit Tif. L.V.
The software that’s bundled with any DSLR certainly supports the unique RAW format produced by that camera. However, versions of Photoshop that are older than CS4 – such as CS3 – do not support the newer cameras’ formats.
That’s because Adobe ceased supporting the older versions. Both Elements 6 and 7 do support the RAW files produced by most of the recent cameras, including the T1i. Anyone who cannot open a RAW file with Elements 6 or 7 will need to download and install the Adobe Camera Raw plug-in version 5.5. See Adobe for the download and for installation instructions. (Photoshop CS4 owners should note that they may also need version 5.5 or later.)
The default with any RAW converter is 8-bit per channel color depth when converting to the TIFF format from a RAW file. Most converter programs also allow you to select 16-bit TIFF. A 16-bit image contains substantially more colour and tonal values: over 4000 intensity levels vs. 256 levels for each pixel. That allows for making more significant changes to an image without posterization: a loss of smooth gradations in tone and color.
On the other hand, stick to 8-bit TIFF unless your image editing software provides a great deal of compatibility with a 16-bit file, such as Lightroom, Aperture 2.2, Photoshop CS3 and CS4.
After your 16-bit file looks perfect – and will need no further adjustments – convert it to 8-bit. (With CS3, you can do so with this command: Image > Mode > select 8-bits/Channel.)
I recommend this step because 16-bit files are huge: twice the size of 8-bit files. Unless you have vast amounts of storage space in your computer (or an external hard drive), you’ll prefer to store the much smaller 8-bit TIFF photos.
You should also print from an 8-bit TIFF. While some software (such as Aperture 2.2) allows for printing from a 16-bit file, Adobe products do not. Even if they did, there is really no great value in printing from the 16-bit TIFF; this is another reason why you may want to save only 8-bit files.