Originally posted by yoon395 Hello all,
I had a question regarding front to back sharpness for a landscape photograph. I'm reading Understanding Exposure by Bryan Peterson and see him continually referring to "presetting the focus via the distance settings on the front of the lens" while using an f/22 aperture to ensure sharpness from a few feet out to infinity.
What exactly is meant by presetting the focus via the distance setting? Is this a feature with particular lenses? I have my Pentax K-x kit lens and a Pentax-A 50mm/1.7 and can't seem to figure out what he's referring to.
Any other tips for front to back sharpness would be appreciated.
Thanks!
You are describing what is know as 'Hyperfocal Distance' used mainly in landscape photography. Easier to demonstrate than explain. When you focus on a subject, a third of the scene in front will be in focus, while two-thirds behind will also be in focus - the point of focus is known as hyperfocal distance. focusing here will give you the maximum possible depth of field. This is best achieved in manual focus of course.
There are charts that offer the hyperfocal distance for a given focal length at a specific aperture, but manually focussing a third of the way into a scene will give you the maximum depth of field.