Wideangle lens and barrel distortion

bobolito · 21-12-2006, 3:20 AM

I have a wideangle lens and it is known they cause barrel distortion. I am researching for a way to correct the barrel distortion (the effect that causes images to become curved/spherical when using wide-angle lens). I currently do this through a plug-in in my video editor, but that adds processing time to the rendering and reduces video resolution. I want to find a lens that I can attach to the camera to correct the distortion but I can't find any. Does anyone know of a manufacturer of a lens that can correct barrel distortion? or maybe a wide-angle lens with barrel distortion correction? Is there such lens for my camcorder?

lurcher · 21-12-2006, 8:47 AM

Whats the camcorder and type/model of W/A lens ?
I keep mine on all the time and have not noticed any issues.

bobolito · 22-12-2006, 6:40 PM

It's a Sony Digital8 Camcorder that uses a standard 37mm diameter lens thread. What kind of wide-angle lens you have?

lurcher · 22-12-2006, 7:39 PM

Got a Sony HC1E with Sony VCL -HG0737Y W/A lens and a Sony SR90 HDD Camcorder with VCL-630X W/A Lens , both are used at the wide side of the zoom with no distortion.

bobolito · 26-12-2006, 8:12 PM

I was checking the specs on the HG0737Y and it is a 0.7x lens. However, I could not find any info on the 630X. What's the wide-angle factor on it?

At 0.7x you won't have noticeable distortion. But I am looking for is between 0.6x and 0.5x. I don't know if there's anything out there that will give me that wide-angle factor without the barrel distortion that makes straight lines look curved near the edges of the screen.

How do professional video cameras correct this? Do they have it built-in?

lurcher · 26-12-2006, 11:18 PM

The 603X has a 0.6x conversion factor , its not a particularly well specified lens unlike the HGO version.
I did try a 0.45 convertor last year and there was distortion and vignetting as you describe.

bobolito · 27-12-2006, 2:41 AM

Yeah, .45x is a bit too much. I have a 0.42x lens and it distorts too much. That's why my boundaries are 0.6x to 0.5x. Where and when did you buy the 603X? I can't seem to find it anywhere on the Internet.

The distortion is nice for certain effects in photography, but that's not usually what I want to do. I am more interested in video.

alpine101 · 27-12-2006, 12:39 PM

Quote:

Originally Posted by bobolito

How do professional video cameras correct this? Do they have it built-in?

They use very expensive lenses that have correction inbuilt rather than add on adaptors...
One of the director Wes Anderson's trademarks is that he loves super wide angle shots. Even with his pro film cameras, there is some distortion visible at the edges of scenes in , for example, La Vie Aquatique.