In this exercise we have a look at distortion. But not only lens distortion as discussed in the previous exercise, but distortion caused through perspective. Basically, there are two types of distortion, optical and perspective. Distortion occurs in two ways either because of the lens or the viewpoint the shot was taken in relation the subject. These will cause the image to either, bow in or lean out. Perspective distortion occurs when, for example we hold the camera at an angle towards the top of a building, the subject will seem to be leaning in. This type of distortion is not lens related. However optical distortion is lens related,
Barrel Distortion is when the image looks like it is blown out from the centre as in the figure on the far right, and the two sides of the image seem to meet at the top centre of the photograph.
The Liverpool City sky line below was taken from our narrow boat as we sailed past.This is a good example of Barrel Distortion. I was in the bow of the boat, and had to use a zoom lens to get the correct frame. (Click here for further reading on framing)
F/5.6 1/640 sec ISO 125 Focal Length 6mm
Pincushion Distortion is when the image seems to lean out as in the image below. NB I did not have an image to show as example for this type of distortion so this image was manipulated, using Lightroom, to show the way it would look
The photographs below bring up the question of taking portraits and distortion. These were taken during a studio lighting workshop. I recently attended. The first portrait of this model, has an enlarged chin, making the image almost into a fish eye. The the second has a thin chin but large sticky out ears and a misshapen head. Neither of these photographs are what you may call flattering. The model would not be happy to display these around the home. So making sure that the camera is level with the model is important, as in the 3rd portrait. This will eliminate the problem of distortion.
Scenario: Choose a subject in front of a background with depth. Select your shortest focal length and take a close low viewpoint, below your subject. Find your natural point of focus and take the shot.
Here is Paddy sitting on a bench with Harley the dog, with a high wall behind them. I am lying on the floor, set my camera to the shortest focal length and snapped away. His head is really small in relation to the rest of his body. The further away from the camera the smaller it would get. His legs look far too big in relation to the rest of his body.
In a previous exercise I have gone into depth about this type of distortion click here to go to that exercise to see more examples.
This distortion may be an effect you want to use when producing creative images like the ones here of the Liver building in Liverpool. In my opinion, the disproportion adds to the aesthetics of the image, making it look grander than it actually is.
In the first image, the building looks like it is leaning in from both sides, just like a road going off into the distance, the further away the narrower it becomes, and the two side meet.
These 3 photographs of the Liver Building were taken with a bridge camera, a Sony Lumix DSC-45, which just goes to prove that even though the lens is attached to the camera and cannot be changed, the zoom facility still has the same effect as a DSLR camera. Additionally, the first two were taken from our narrow boat as we sailed past the iconic building so synonymous with Liverpool.
(1st image – f/5.6 1/640 sec ISO 125 Focal Length 6mm)
In the 2nd image, the distortion is exaggerated as I was standing in our narrow boat and took the shot pointing the camera upwards, as we approached the building. The right of the building looks a lot thinner than left hand side, yet in reality they are symmetrical.
f.5,6 1/800 sec ISO 125 Focal Length 6mm
f/5.6 1/500 sec ISO 125 Focal Length 6mm
In the 3rd photograph taken from a different viewpoint, the building on the right is a good example of the way a mixture of the elements can really distort the images we take. There are programmes that can fix this, but its always better to get it right while on site, rather than fix it later using photoshop.
The Photograph Life has a very good simple section on the various types of distortion Click Here for link to the web site
Previous Related Exercises
If you REALLY want to use photoshop to correct a distortion, here is a link to help you Click Here