digital still cameras
You can change both the resolution and the compression level of the pictures you take with a digital camera. Resolution refers to the dimensions of the images as measured in pixels and compression refers to the amount of data used to describe the image.
Taken together, these two settings let you make trade-offs between image quality and file size. The smaller the filesize, the lower the quality and the more images you can fit onto a memory card, and vice versa.
In general, use higher quality settings when your destination is a print of any kind. For Web work, you can get away with lower quality settings (though the lowest quality is seldom recommended).
Common resolutions are:
- 3456 x 2304 - the best possible resolution on the Canon Rebel, not available on other cameras covered here. Using this resolution will dramatically reduce the number of shots you can fit on a card.
- 2592 x 1944 - the best possible resolution on the PowerShot G5, not available on the G1.
- 1024 x 768 - a middle ground that produces pictures with good enough resolution for use on a Web page, and allowing you to take a large number of pictures on a flash card.
- 640 x 480 - the lowest quality, which allows you to take the largest number of photos on a single flash card. This resolution is still be good enough in many cases for photographs being used on Web pages. Use this resolution only if caught in the field without an extra memory card.
Set the resolution from the Shooting menu. Press the camera's MENU button and navigate to the Shooting tab, then down to the Resolution or Image Quality sub-menu.
On the PowerShot cameras, use the Omni Selector dial, the gray button with four arrows that's on the back top right of the camera, to navigate through the menu. On the Rebel, the arrow keys work much like the Omni Selector. Press on the downward pointing arrow until the Resolution settings line is highlighted. Then press the right or left arrows to move between and select a resolution. For Web purposes, we recommend using a resolution of at least 1024x768. For print purposes, we recommend using a resolution of at least 2048 x 1564.
To retain the setting you've chosen and leave the menu, press SET and then the MENU button again.
Some cameras also let you access the image resolution directly, without going all the way through the menu system. On the PowerShot G5 and Pro1, set the resolution by pressing the FUNC button on the back of the camera. Then use the Omni Selector, the gray button with four arrows that's on the back top right of the camera, to scroll down to the bottom entry in the list for resolution.