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Should one choose a (ultra wide) lens with the lowest possible distortion even though its resolution is not very good, over a lens that is very sharp, but has noticeable (barrel/mustache) distortion?

Example is the Sigma 12-24mm Mark I (low distortion, so-so resolution) VS Sigma 12-24 Mark II (pronounced distortion, far better resolution than Mk. I).

Will the lower distortion lens save a lot more time for the real estate photographer's workflow? Or is better resolution worth the added post-processing time?

  • Which type of real estate photography? Exterior? Interior? are you trying to correct those 93° photographs of a room into something that looks more natural? – user13451 May 9 '15 at 0:49
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You can correct lens distortion in post, but you do so at the expense of some of that higher resolution. Roger Cicala of LensRentals.com says in a blog post where he tests the uncorrected and post corrected resolution of an EF 24-105mm f/4 L lens at 24mm:

But when someone wants to argue that they buy a lens with high distortion because it has higher resolution and distortion is easy to fix in post . . . well, it had better be a lot higher, or it's a fool's argument.

He goes on to say that it is fairly well established knowledge among lens designers that correcting for distortion in the lens also reduces resolution versus leaving the distortion uncorrected. In the past the distortion correction was deemed to be worth the loss of resolution. The current trend is to leave the distortion uncorrected to gain the resolution.

There is a lot of good additional info in the comments to Roger's blog post referenced above.

With that taken into consideration, in terms of your final results the additional workflow to correct the distortion from the high resolution/high distortion lens may not give you any significant gain in resolution versus a lower resolution lens with low enough distortion that it does not require correction.

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    Interesting, i knew of course that image warping must degrade the image somewhat, but i'm astonished by the amount in the test. – ths May 8 '15 at 23:17
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    @Jasen I think Michael is suggesting that it is a trade-off, rather than a "don't do it" situation. So the photographer must weigh up whether it is needed for a particular situation, and since, in this case it is a must, then the photographer will use the technique with the highest end resolution. – damned truths May 8 '15 at 23:58
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    @Jasen What do you mean by "wide-angle distortion"? If you mean, e.g., barrel distortion, that can occur with any lens. If you mean, e.g., strongly converging verticals, that can also occur with any lens. That effect is more pronounced with wide-angle lenses because they include verticals farther from the centre of the frame. The solution to that is to make sure that the camera is level: the cause is pointing the camera upwards (or downwards) from the horizontal, not using a wide-angle lens. – David Richerby May 9 '15 at 10:15
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    In which case the only real solution is a tilt/shift lens. – Michael C May 9 '15 at 12:17
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    If one is dealing with pointing a lens up/down and regularly using it for architectural type work wouldn't it be sensible to spend the money for the Nikon 24mm f/3.5 PC lens? Canon 24 f/3.5 TS (or that 17mm f/4 TS) lens? Yes, they are expensive lenses... but if you are going to be using that feature... – user13451 May 9 '15 at 16:11
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Lens distortion can be corrected for automatically by programs like Lightroom, Photoshop or PTLens for the bold, if a profile for that lens exists (and if not, you can pretty easily make one yourself). Sharpness cannot be recovered in post, so this seems like a no-brainer.

Take the sharp but distorted lens and let your software auto-correct it, with no additional effort.

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    And any time you remap the pixels, such as applying distortion correction, you lose resolution... – Michael C May 8 '15 at 22:35
  • sharpness can be recovered so some extent, if using a low-noise sensor – Sarge Borsch May 9 '15 at 15:01
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I work in real estate photography, It really does not matter about the resolution, since the images are going to end up on a website with 1024px on it's longest side, distortion however does show up even after you correct the lens, I have two Sigma's 12-24mm and used them a lot in the past, now I am shooting with the Canon 17-40mm to force myself shooting with a longer focal length.

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If you are using Lightroom distortion is not an issue. Lightroom corrects distortion for a lens by its profile it takes seconds to run a batch. Every ultrwide will have distortion you need to deal with.... period.

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You can also take multiple overlapping images covering the entire building and then stitch a final high resolution picture together using e.g. the free of charge program Hugin. If you make sure the overlap is big enough so that you are only using the part of the pictures that are not far removed from the center, then the barrel distortion won't cause problems.

Of course, this is rather time consuming, so you will only want to do this for special projects requiring extremely high resolution.

  • In my experience, stitching together panoramas doesn't work well for situations where it's substituting for a very wide-angle lens. Perhaps Hugin does a better job than other software I've used so I'll give that a go next time I have a panorama to stitch. – David Richerby May 9 '15 at 20:30
  • @DavidRicherby You can always stitch the panorama using one of the standard projections first and then you are free to apply whatever mapping you desire to get to the desired final result. There may be some loss of image quality due to the mapping, which is only going cause [problems if this is non uniform (e.g. if the image looks a lot less sharp away from the center). But then if you start out with a high enough resolution, you can remap the image in such a way so as to make the final image look exactly like that image taken with your favorite wide-angle lens. – Count Iblis May 10 '15 at 16:01

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