American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "f-stop" in a sentence
"Notice the decrease in sharpness as I increased the f-stop (decreased the aperture diameter)."
"Few of God's wonders are as inspiring as a waterfall: Ah ... wide-angle lens, 1/8-second exposure (without a tripod), f-stop, let's see ..."
"Buy a camera that goes down to an f-stop of at least 2.8."