Gerald from MN writes:
Is there any difference in a DSLR (digital single lens reflex) camera’s battery storage capacity between a large image size selection vs. a small image size selection? Can I expect to take more pictures on a battery using a Large size image selection versus a Small image size selection?
The simple answer to your question is no, image size does not affect battery life significantly. The image sensor needs to be activated fully to record an image, then the processor needs to activate to downsample the image, so there is roughly the same energy usage versus writing a larger non-compressed image. So what can you do to save battery then? Here are some suggestions starting with the most power savings.
Use The Optical Viewfinder: If your camera has an optical viewfinder and a LCD screen to frame photos, use the optical viewfinder. Since the viewfinder uses a mirror to display the image from the lens and not the image sensor, you won’t be using power for the sensor or LCD display.
Turn Off Automatic LCD Review: This is the setting in your camera which automatically displays the image you just took on the LCD screen. The LCD screen is the most power hungry portion of a camera, so turning off automatic image review will save a lot of power.
Turn Off Continuous Autofocus: Continuous autofocus is a great option for shooting sports, but in other situations the constant adjustment and activation of the focus motors will wear your battery down. Most cameras support focusing by half-pressing the shutter button; if you need to refocus just release the shutter button and half-press it again.
Turn Down Meter Timeout: The metering system evaluates the lighting conditions to correctly set the exposure uses battery to measure the scene and lighting. Turning down the duration of the meter can save battery life.
Buy A Backup Battery: Okay, this one isn’t really battery savings, but it’s a good idea. Even if your camera has a very long battery life, it’s always a good idea to have a backup. You don’t want to be somewhere and realize you forgot to charge your battery or have battery failure. You could end up coming home without any photos at all.