YouTube videos of correcting lens
distortion with Photoshop:
1,
2
Original image of Basilica Notre Dame de
Fourviere in Lyon, France Taken with an effective (35 mm) focal length of 25 mm showing inward
tilting of the towers from distortion of wide angle lens
EXIF data
F.L. of 4.1 mm equals 25 mm (35 mm
equivalent)
Print-screen image of Photoshop's Lens
Correction Filter
Using Adobe Photoshop CS3. On the menu at the top choose: Filter --
Distort -- Lens Correction. I then set the Transform Vertical
Perspective near the bottom to -95 with the slider to help correct
the twin towers from leaning in and give them a parallel appearance.
Then adjusted the Transform Horizontal
Perspective to -7so the tops of the towers would be
of similar width. I also did a mild correction of +3.00 at the top Remove Distortion
to produce a slight pin-cushion effect (remove the slight bulging out of
the towers).
The settings were determined visually on what looked best.
. Note that when the image is tilted to remove the
distortion there is some loss of the peripheral image.
(you may mouse click twice over the image for an
enlargement)
Flattened corrected image
Cropped corrected image
Note the loss of some of the image
especially on the right after distortion correction.
An alternative would be to take multiple overlapping photos at a longer
focal length (which has less distortion) and then stitch them together as
a panorama in post-processing. If successful, the panorama would
give you a wide-field view equal or greater than from a wide-angle lens,
but with less distortion and higher resolution.