Barrel Distortion

[ketan]

Hi,
When you take building photo or any indoor photo with wide angle it shows clearly slanting walls. This can be corrected in photoshop etc, but is there a way to avoid this ? Is this a function of camera or lens ? Does all camera have this ?
Ketan:hail:

 

[gizmo2071]

It's not barrel distortion, barrel distortion makes the edges of the shots have a curved appearence, this is more common in wide angle lenses.
What your talking about is converging lines.
This can only be corrected with large format cameras or certain lenses with bellows that attach to other formats.
The film/digital sensor has to be at a 90° angle to the building(by this I mean parralell to the building) and then you would move the lens element, which isn't possible on most camera formats.
I mean unless you can get up higher and shoot the building straight on, then you'll struggle to avoid this.

Post processing will be your only option, using the "perspective" tool to straight then converging verticles and then "transform" to re-scale.

 

[deanimator]

You mean the vertical lines, right?
(Or barrel distortion...something completely different which creates bowed out straight lines!)
They slant back because of perspective.

Solutions:

1) The easiest way: If you point your camera directly at the building, from far enough away, you will get the complete building in the frame, but including a lot of foreground that you don´t want. Crop this in Photoshop or any other program.

2) Use the perspective control tools in Photoshop (as you mentioned), or use Helicon Filter...a software which is probably better at all the distortion corrections. Google it for a free trial.

3) Buy a perspective control lens. VERY expensive.