PDA

View Full Version : Geometry involved in photography?



Angela_1158
1-May-2000, 21:36
How is geometry involved in photography? Do photographers incorporate it in the photos? Is it involved in focusing reflected light into the image?

Chris Hawkins
2-May-2000, 07:15
Sigh...... Geometry is normally discussed and taught using drawings and equations. Neither of which are practical with the text based system on this forum. I suggest you preruse the optics section of photo.net at http://www.photo.net/photo/optics/index.html and View Camera Technique by Where oh where Bob Atkins when we need him!

Chris Hawkins
2-May-2000, 07:20
Correction to above: I suggest you preruse the optics section of photo.net at http://www.photo.net/photo/optics/index.html and View Camera Technique by Leslie Stroebel.

David_892
2-May-2000, 07:50
What exactly do yu mean? If you are talking about in photos in a pictorial sense, e.g the arrangement of a still life and such like, then you can use it if you, or whoever is paying you likes it. If it is in the more technical aspect, such as schemphlung (NB probably wrong spelling) or other such corrections that can be made with camera movents, than you are best consulting the information provided buy other posts.

Robert A. Zeichner
2-May-2000, 08:23
In some ways, geometry is so intrinsic to Large Format photography that there is hardly a procedure we perform that doesn't escape it's grasp. The peculiar thing about it is that one doesn't really think about all of this when actually making photographs. If we were to examine what we have done after the fact and put these practices into the form of drawings and rules, the result would be a course in geometry. There is little time to measure angles and use formulas to calculate exactly what needs to be done. Rather, most of us, I believe, work intuitively using the information that we've read after the sun sets and our personal experience to guide us along. Some obvious examples of geometry in action would of course be Scheimpflug, a rule that enables objects along a single plane to be brought in sharp focus by altering the film and lens planes and the business of lens coverage as it relates to the use of swing, tilt, rise and fall movements. But, there are many less obvious applications such as the way film holders can be measured for flatness and depth. Of course, some of the more subjective aspects of image composition and the way one geometrically divides the ground glass into sections is yet another example. What an interesting question! I'm curious why you ask this. Is your interest in this from a photographic or geometric perspective?

Sean Billy Bob Boy yates
2-May-2000, 10:21
"preruse" ?

Pete Andrews
2-May-2000, 10:50
The word "geometry" also has another meaning when applied to lenses. It can be used to describe how well a lens renders straight lines straight, or whether the reproduction scale changes from the centre of the field to the edge. For instance; a lens exhibiting barrel distortion could be described as having poor geometry.

On a more philosophical level, we wouldn't have lenses at all without geometry, nor a good deal of the rest of civilisation as we know it, such as architecture or the ice cube.

David Richhart
2-May-2000, 21:55
Angela...When in doubt,trip the shutter...

Angela_1158
2-May-2000, 23:13
This is Angela and I just wanted to say thanks! You've helped a lot!

Chris Hawkins
4-May-2000, 17:08
Sean: I never was much of a speller... It should have been "peruse."