Lens Correction in Photoshop

As a painter, I’m cursed. One of the things I have to always consider is documenting my paintings. What curses me is the curvature of the lens. By virtue of the curve, straight lines always come out curving around a bulge in photographs.  That’s the lens doing that. It’s called field distortion and it drives me crazy.

I could fix it by buying a lens for my camera that would correct it, but they’re expensive.

I could buy software such as DxO Optics Pro. It too can be expensive. DxO Optics Pro retails for $253.00 CAD.

I have Photoshop already… and guess what? It comes with a lens correction filter already (as of CS2). As it turned out, I had the perfect image to try it out on. I did a painting of Queen Street in Toronto from a series I’ve been working on of a row of buildings. As you can see in my original image, the distortion isn’t bad. But enough that I’m not happy with the way it is.

The second image shows guides to see just how far off it really is. Not much… but enough. Click for the enlargement to see the detail.

Original image

Original image

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From the Filter menu, go to Distort -> Lens Correction.

That calls up a workspace window with controls on the right hand side and tools on the left.

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The Workspace

The Workspace

Closeup of Menu

Here’s a closeup of the controls.

Remove Distortion is a setting that controls which way the distortion will operate, convex or concave.

Chromatic Aberration is when your channels or areas in your channels are not aligned and you get an offset occurring.

Vignette is when an area of your photograph is fuzzy and out of focus.

Transform refers to the entire image tilting in perspective top to bottom (vertical perspective) or swinging left to right (horizontal perspective).

The Edge and Scale settings refer to when the image is distorted to correct the aberration, the filter will squish in the image, pulling it away from the original edge of the image. This setting tells the filter what to put there in its place. The default is transparency, or in other words nothing.

So the first thing I need to do is straighten the image by rotating 1 degree. You can see the canvas exposed along the edges after the rotation. Had I changed the Edge setting to a fill colour, the exposed areas would be solid and not transparent.

Then I changed the horizontal perspective to -4 and the vertical to +6 to align the front picture plane to the viewer.

This was the result. It was enough that it represented what I wanted. Just enough to remove most of the distortion. I’m not going to fuss too much with it. The more I fuss, the less people are going to believe that this is what my painting really looks like.

From here, I used Free Distort to align and straighten the edges more

The final image

The final image

My finished file. 🙂

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