View Full Version : How can I counter the distortion of a fisheye?


Matt Blair
January 21st, 2004, 02:21 PM
That's a long subject. . . . .

I make video tours of houses, and I have the .3x century optics 37mm lens. . .with a Sony TRV11. I wanted the lens so that I can get a much wider view of the house (since I'm working on confined spaces), but it seems the distortion is way too much!!

Are there any filters for Adobe Premiere that could pull the corners outward to counter the distortion?

Kind of like this. . . . .

A still, with the corners represented with numbers. . . .

1-2-3
4-5-6
7-8-9

And, change that frame to (and cropping back to original size)

1---2---3
--4-5-6--
7---8---9

(the hyphens are just so that I can position the numbers right, pretend they aren't even there)

In effect. . .pulling the top right/left corners and bottom right/left corners outward to counter the distortion caused by a fisheye.

Robert Knecht Schmidt
January 21st, 2004, 02:28 PM
You're talking about barrel distortion. Google brings up this link (http://www.ferrario.com/ruether/perspective-correction.htm). Also, The Imaging Factory (http://www.theimagingfactory.com/) makes a Debarrelizer plugin. Note that it's best not to zoom when acquiring footage that will be treated in post.

Mark Jefferson
January 21st, 2004, 02:44 PM
Also, AfterEffects has a filter that corrects fish-eye distortion

Cheers,
Mark Jefferson

Adrian Douglas
January 21st, 2004, 10:33 PM
Filters that correct distortion do so quite well but you lose quite a bit of the field of view. You'd probably be better off selling the fisheye and getting a decent .6 wide angle adapter

Bill Pryor
January 22nd, 2004, 09:43 AM
One reason for using a fisheye is to get the distortion. As the above post suggested, dump the fisheye and go with a wide angle, although when you tilt it up or down you probably will get some distortion near the edges.

Mark Jefferson
January 22nd, 2004, 02:05 PM
Actually, the AE filter warps the image so it is (relatively) straight. You don't lose any field of view.