Lens Distortion

lennon33x · Jan 28, 2014

I'm interesting in purchasing a moderately WA lens (between 28-35mm). My 50 is just slightly too long in certain situations. I can get a better deal about with a Sigma 30mm 1.4 or a Canon 28mm 1.8/2.8 than the Sigma 35mm 1.4 (which I would love to have, but don't have that much cash). I love primes, but I'm also tempted with a moderate zoom (the Tokina 24-70 (I think?)).

So my concern is the lens distortion. I know when you down to about 24-28, you can get some pretty wicked distortion, especially at close up views. How bad is 28 compared to 35? Also, will the lens profiles correct this in LR so that it's not quite so noticeable?

Derrel · Jan 28, 2014

Let's put it this way: on FF, with a 24mm, the corners of the frame have a LOT of apparent perspective distortion on people and objects...people at the edges of the frame appear "stretched" and "warped"...it's a VERY significant effect. At 28mm, the bent-over-and stretched out people is much,much less significant at the edges of the frame; with 35mm, the effect is almost gone, but not quite.

One of the big fashiony portrait stars, Sue Bryce, LOVES her Canon 35mm f/1.4-L as a glamour/boudoir/fashion portraiture lens. Yes, that's not a typo; her MAIN prime is the 35mm f/1.4 L. The thirty-five millimeter; but, she has to continually "warp" the upper arms and torsos of the women she photographs with that lens, because, well, the lens causes a lot of apparent perspective distortion.

I am not talking about barrel distortion: I mean that the 24mm SIGNIFICANTLY distorts human features (and architectural features, or whatever) at the edges, and the corners, to a HIGH degree; the 28mm lens significantly LESS so; and the 35mm to only a very slight degree. I believe it's like ~10 degrees wider with each step from 34/28/24mm.

Lightroom's lens profiles can correct for geometric distortion like barrel distortion, but they do not remove the apparent perspective distortion. DxO OPtics Pro is an application software you might be interested in.

DxO Optics Pro Software

lennon33x · Jan 28, 2014

Derrel said:
Let's put it this way: on FF, with a 24mm, the corners of the frame have a LOT of apparent perspective distortion on people and objects...people at the edges of the frame appear "stretched" and "warped"...it's a VERY significant effect. At 28mm, the bent-over-and stretched out people is much,much less significant at the edges of the frame; with 35mm, the effect is almost gone, but not quite.

One of the big fashiony portrait stars, Sue Bryce, LOVES her Canon 35mm f/1.4-L as a glamour/boudoir/fashion portraiture lens. Yes, that's not a typo; her MAIN prime is the 35mm f/1.4 L. The thirty-five millimeter; but, she has to continually "warp" the upper arms and torsos of the women she photographs with that lens, because, well, the lens causes a lot of apparent perspective distortion.

I am not talking about barrel distortion: I mean that the 24 distortion human features (and architectural features, whatever) at the edges, and the corners, to a HIGH degree; the 28mm lens significantly LESS so; and the 35mm to only a very slight degree.

Lightroom's lens profiles can correct for geometric distortion like barrel distortion, but they do not remove the apparent perspective distortion. DxO OPtics Pro is an application software you might be interested in.

DxO Optics Pro Software

When I do shoot people at a wider focal length, for my purposes, I wouldn't be as close as I would for a portrait. I'm trying to make the justification in getting just a little wider. If I ever need to get a portrait, I would obviously switch to my 85mm. So in your opinion, the 28 is just fine?

Derrel · Jan 28, 2014

Well, I think the 28mm wide-angle is a fine lens length. It's wide in angle of view, and it does not make the distant stuff look sooooooo faraway and tiny as say a 20mm does, or even a 24mm does. 28mm is a good, easy wide angle lens to work with, and it makes pictures that have a wide-ish angle of view, but NOT a terrible or objectionable amount of weird edge distortion. It's "wide" yes, but it does not look "gimmicky" or "weird". It's a good compromise wide-angle, and can be used with MUCH less "bent over backwards" effect on say, groups of people in a room standing behind the birthday cake...with a 24mm, the people on the edges of the frame, and ESPECIALLY at the corner, look, well, bent-over, or stretched out; 28mm does NOT do that to nearly such an extent.

35mm is more "naturalistic". It's a sort of semi-wide lens.

If you WANT to make things look somewhat natural, and yet still have a wide-angle view, then 28mm is a good choice. 24mm looks like a very obvious "lensy" look. With a 24mm the lens looks like it is a part of the picture..the 24mm puts a "lensy" look onto everyday scenes; it makes the foreground objects large, and makes the background objects appear smaller, and more-distant. It is the beginning of the wide-angle territory, in my opinion.

The 28mm lens, not quite so "lensy", not so "OBVIOUS" as the 24mm is, and the background does not appear so small, nor quite so distant. 28mm is the longest lens that can be considered a wide-angle lens, and it has been made for a long,long long time because it's a very useful lens length.

The 35mm looks reasonably close to the way the human eye sees. It has deep depth of field when well stopped down to f/11 or f/16, and the background does NOT appear really small and really far-away. If the lens is FAST, like f/1.4, the 35mm length can give shallow DOF effects on close-up subjects. Nikon first made a 35mm f/1.4 in the late 1960's, and has made one continuously. it is a VERY useful lens for normal, everyday scenes.

I'm going to give an analogy; 35mm lens is like driving 45MPH; the 28mm lens is like going 65MPH; the 24mm lens is like driving 100 MPH.