topic Re: Lens distortion (curving) in EOS DSLR & Mirrorless Cameras

Lens distortion (curving)

shoutinhalls — Fri, 04 Mar 2016 23:01:48 GMT

I have noticed that when I attempt to straighten photos (especially of buildings), they never seem to line up properly due to curving on the sides. I realize that this is probably the curve of the lens, but I am wondering if there is a setting or workaround to get a perfectly straight picture. Either that or a different lens to use.

Camera: Canon EOS Rebel T5

Lens: EF-S 18-55mm IS II

Thanks!

Re: Lens distortion (curving)

kvbarkley — Fri, 04 Mar 2016 23:12:07 GMT

What software are you using?

Many packages, like DPP allow you to correct for lens distortion - some have corrections for various lenses built in.

According to Ken Rockwell, your lens has the following distortion:

18 mm: Strong barrel distortion. Corrects best with +5.0, but remains a little bit wavy.

24 mm: Barrel distortion. Correct with +2.2.

28 mm: Very slight barrel distortion. Correct with +0.5.

35 mm: No distortion.

55 mm: Negligible pincushion distortion. leave it alone, or use -0.2.

As you can see, it is best to shoot at 35mm if you want no distortion.

Otherwise, a new lens is in order.

Re: Lens distortion (curving)

shoutinhalls — Fri, 04 Mar 2016 23:19:18 GMT

Nice, I will give that a try!

I have been using Lightroom but very new at it. The screenshot was from the photos app because I have Lightroom attached to another partition on my Mac. I believe I know where the option for lens correction is but didn't understand it until now.

Re: Lens distortion (curving)

kvbarkley — Fri, 04 Mar 2016 23:20:50 GMT

Lightroom should be able to do it easily. There is a plug-in for photos, that you might want to get, too.

Re: Lens distortion (curving)

ScottyP — Sat, 05 Mar 2016 04:35:21 GMT

Lightroom can adjust for the distortion. Be sure you don't frame the shot very tightly, however, because when LR corrects for the edge distortion it crops pieces off of the image around the edges. Leave some slack room around the edges.

If you are a bit more serious about architectural shots you can look into prime lenses or top end zooms with less distortion. (Research before you buy because some are better than others.)

If you are really really really serious about it you can buy a tilt shift lens. They are all manual focus and somewhat tricky to use. If you were this serious on architectural, you'd probably already have one.

Re: Lens distortion (curving)

jrhoffman75 — Sat, 05 Mar 2016 14:40:34 GMT

You could also use Canon DPP and use the lens correction data Canon provides.