A reader inquired via a comment on my previous blog post (“Seeking Blue on Blue“) about why I didn’t correct for the distortion of the church spire in my Blue Church photo captured in Bratislava, Slovakia. For reference, a small version of the photo is included to the right here.
The primary reason I didn’t correct the geometric distortion of the scene is that it was there intentionally. My feeling was that the Blue Church is already a bit of an unusual subject visually, and so I thought that a wide-angle shot that created an exaggeration of the unusual nature of the subject might be interesting. I actually captured other shots with a longer lens from a position further from the church, but favored the distorted image as being a bit more interesting visually.
So, the short answer is that the ideal solution if I didn’t want that distortion was to capture a different image, not to capture a wide-angle shot and then remove the distortion in post-processing.
And this raises another issue that I think is worth exploring. Specifically, if you don’t want distortion in the image, it is really best to avoid it in the first place. To be sure, you can apply lens correction adjustments and transformations to an image in order to straighten it out. But if you photograph a subject up close with a wide-angle lens rather than backing up and using a longer lens, the degree of correction is going to be significant.
Consider, for example, this version of the same image, which provides a sense of how much the image must be manipulated to achieve a somewhat straightened belltower:
Naturally if this was my intent for the image I would need to crop rather significantly. Hopefully I would have taken that into account in the initial capture, leaving some room around the subject so that I could crop without losing any key areas of the photo.
However, this strong transformation also creates a problem in terms of image quality. All that stretching and skewing of the pixels means more than a few pixels will need to be added or removed from the image. The result is a loss of sharpness and detail in the photo. In fact, the result can be a very significant reduction in image quality. That might not be a problem if the image will only be shared online, but if you’ll print the photo that loss of quality can have a big impact.
Obviously the choice of lens and–by extension–the choice of position relative to the subject plays a key role in defining the final image. In this case I opted for a distorted look, so I went out of my way to get close with a short lens. I could have taken a different approach, of course. But I would suggest that the worst approach would have been to capture an image with distortion you intended to remove later, unless it was simply impossible to capture the image you were really after.
What do you think? Should I have avoided the distortion in this case? Feel free to share your thoughts in the comments below.