Another Look at Wide Angle Distortion
Photoshop wins a round; color balance takes a holiday; cropping solves almost everything (except what it destroys)
I continued to explore options for dealing with serious distortion in wide-angle images and I came up with…nothing new as far as tools. This is because all of the image editing programs only provide two methods for dealing with lens distortions:
Customized lens data supplied by the manufacturer is used to model typical distortion (and in some cases, if you really know what you are doing, you can make your own, but I don’t know how to do that and find it daunting, so it remains unexplored for now).
Basic distortion adjustments that assume the distortion is regular across the entire lens. This is seldom true, and is especially not true of the 17mm Canon TS-E.
So, I used the oldest ‘trick’ in the book for lens distortion: I cropped out what I found too objectionable. But there was a new break in the story, because Photoshop did a better job on this panorama than Affinity Photo did. Affinity removed some parts of the image, and Photoshop left them in. And it appears to my eye that Photoshop did a better job of matching the images to each other while (accidentally, I suppose) doing an excellent job of correcting the distortions (just as Affinity had, only PS did it better).
This left me with another oval image when the panorama tools removed the distortion:
So I cropped to get a regular image (mostly because I did not think it worthwhile to hand-edit the boundary to make it more regular, but that approach would also work just as it did in Affinity Photo). That rectangular image is at the top of the post.
The gain here is the roots included at far left (which Affinity lost track of); the loss is that a good portion of the sky reflection in the water went away.
I guess the lesson here is to either stick to very conventional and not terribly wide lenses, or to gird yourself for the extra work of dealing with many ultra-wide lenses. That said, there are some superb ultra-wide designs out there; I have a 23mm (which should provide about the same useful coverage as the 17mm) in a week or so to try out.
Note: See my earlier post on this same subject for further information about the performance of the 17mm lens)
Here are two images taken with the 17mm Canon TS-E lens. One is the full image; the other is a square crop that removes a good deal of the distortion. I think these demonstrate that the distortion is not actually evil, that it can add some dash to a landscape image. I like both versions myself, and they have significantly different character for me.
Basically, the image with the distortions left in has a very expansive, active appearance. The square crop is more static, has a very different feel to it for me.