Photographic Distortion

[brianstoiber]

My question is someone theoretical in nature. If I needed to photograph a 12x8 foot flat object that is standing vertically (perpendicular to a camera on a tripod), using a 18-55mm lens, how far back would I need to stand so that I wouldn't have distortion in the picture?

 

[Designer]

My question is someone theoretical in nature. If I needed to photograph a 12x8 foot flat object that is standing vertically (perpendicular to a camera on a tripod), using a 18-55mm lens, how far back would I need to stand so that I wouldn't have distortion in the picture?

I can't say for sure, but here are some factors of which to be aware:

Using the longest end (i.e.: 55mm) get back as far as you can and still keep a reasonable amount of detail in the piece. I presume we would be talking about 30 to 35 feet distant.

Position your camera at about the halfway point up the panel, i.e.: 6 feet above the ground. Keep your lens as perpendicular to the panel as you can. i.e.: positioned at a point that is (projected) to be right in the center of the panel, pointing directly at the center of the panel. Do not tilt the lens up or down or left or right.

Here is where a tape measure will come in handy. Really measure your setup so you are confident that the camera is pointing at the middle of the panel.

 

[john.margetts]

What camera? With an APS-C sensor, you need your focal length to be close to 27mm and for a "full frame" sensor, close to 43mm, and then stand back as far as is necessary to fit it all in. This will give you the same type and level of distortion that our eyes produce so will not be apparent.

 

[weepete]

as long as the lens doesn't introduce it at those focal lengths. Profile correction can help as can the wide angle filter in photoshop if it does. Spirit levels are a great tool to help get the vertical plane aligned

 

[Ysarex]

My question is someone theoretical in nature. If I needed to photograph a 12x8 foot flat object that is standing vertically (perpendicular to a camera on a tripod), using a 18-55mm lens, how far back would I need to stand so that I wouldn't have distortion in the picture?

No distance. Your 18-55mm lenses will not be distortion free (it's a zoom lens) and will display distortion at all distances. Place the camera at a height of either 6 or 4 feet depending on the orientation of your subject. Center the camera on the subject. Use a distortion free lens and back up the distance necessary to frame the subject.

Joe

P.S. Software in the camera and/or processing software generally does a decent job correcting distortion.

 

[Dave442]

The pCAM app can tell you the distance to stand depending on focal length you select. On that lens I would just use 55mm and f/8 as a starting point.

 

[fmw]

Frame the image wider than required for the final image and use post process to correct all or some of the distortion.