he traditional measure of image sharpness is stated in line pairs per millimeter � abbreviated aslp/mm. In other words the ability of the human eye to discerned the number of high-contrast pairs of lines appearing in the space of a single millimeter.
You may have read that some very high resolution B&W films can reach over 150 lp/mm.That’s amazing. Some really terrific lenses can actually resolve somewhat over 100 lp/mm.Wow.
But are you also aware that even the very best colour printing papers can reproduce little better than 75 lp/mm?Humm. Are you also aware that the human eye isn’t able to resolve any more than between 5â��10 lp/mm under the most optimum conditions?Say what?
Forgive me, but I’m having a bit of fun with you by my editorial comments because so many photographers get hung-up on theory and specs rather than what they actually can perceive with their own eyes.
Think about the variables standing between a scene in front of the camera and a print hanging on the wall. A large number of factors determine whether or not the print will be sharp.