Hello, this is Rick Allen and welcome to another podcast.  For the last several weeks, we have alternated between discussing Elements of Design and Dynamic Symmetry as a means to improve in-camera composition and post production retouching.  Today, we will focus on Perspective ...
**** ... - what is it and how the mind uses it for clues to determine the depth of an image.

But before we proceed, let’s just start with a few basic facts. 
****
Objects closer to us are appear larger - and brighter - than those farther away.
Parallel lines will eventually converge to a point.
The distant horizon will appear to have lower contrast and saturation than regions closer to us.

What do all of these statements have in common?  Simply that we constantly see and use visual clues to create a sense of depth.  Except for those of us who are visually challenged, every viewer is an expert in perspective. 

**** As photographers and retouchers, there are multiple strategies to enhance - or reduce - the sense of depth in our images so as to communicate a vision or story. 

**** One of the laments of photographers is that viewers frequently object when an image is retouched, because of some sense that photographs accurately represent truth or reality. 
**** In my opinion, it is precisely because photography can so accurately capture a sense of perspective that leads viewers to think of photographs as real. 

**** How many more literal clues could have I provided in this picture to show convergence??

**** Actually several more, because of the implied lines of how Hess is kneeling and the direction in which he is looking. 

**** Perspective can be defined as the relationship between objects in space and the viewer. 

**** In the 2 dimensional world of photography, the most prominent type of perspective is Linear Perspective.  This form is most frequently characterized by converging lines.  A road extending to a vanishing point in the distance is another classic representation of linear perspective. 
One of the reasons convergence is such a popular design tool is because converging lines - by definition - appear diagonally in the image, and we know from previous podcasts and our own experience that diagonal lines add to a sense of tension and movement in a picture. 

In this particular image, there are no strictly horizontal lines, although the one cutting Sam about the waist is pretty close. 

**** As with the picture of Hess, this image also has implied perspective lines, extending from their faces to points outside the frame.  Coincidentally, in my recent podcast on Eye line and Ambiguous Backgrounds, I mentioned that one can insert ambiguity into an image by introducing opposing Eye Lines.  In this case, Brittany is looking out camera left, while Sam is looking more or less directly at the camera.  The purpose of opposing eye lines in this picture is to create multiple focal points:  one camera left, a vanishing point to the rear, and Sam’s direct gaze.


**** One technique that works particularly well is when there are either
**** two vanishing points, or if ....
****  ...the converging diagonal lines also have diagonal shadow lines.  Art Wolfe’s and Frans Lanting’s images instantly come to mind, as they have mastered this subtle but effective technique of depth perception. 

The position of the camera or the creative use of warp or transform determines the degree of convergence.  Unfortunatly, I am not as good a photographer as either Art or Frans, so this image doesn’t come close to doing justice the technique they have perfected.

**** One way of enhancing perspective in camera is to get closer to the ground, but not so close that the vanishing point disappears from the viewfinder.  As in this image, Perspective can be dramatically enhanced by your choice of lens.  Generally speaking, a wide angle lens will show more convergence than a telephoto lens.  It is for this reason that I frequently use a 14mm super wide lens, precisely because it accentuates foreground elements, and when positioned carefully can create lines where none are obvious to the eye. 

**** If there is a challenge to the use of the super wide lenses, it is that the lines may not classically lead to a single vanishing point.  In this case, the layers of sandstone are the result of sedimentation, and not the optical effect of large foreground / small background.  That said, lines in an image can mimic lines of perspective, and it is that similarity that make this image suggestive.

**** If wide angle lenses help accentuate depth, then telephoto lenses compress it.
**** This can be used in quite creative ways to connect lines in the mid-ground and back-ground that again would not be obvious to the eye.

**** Another form of linear perspective is where otherwise similar or identically shaped elements appear smaller as they repeat into the distance.  This is called Diminishing Perspective.  One of the more effective ways of accentuating perspective is to make sure there is an element of scale.  This is accomplished by including in the image some element or shape that is immediately recognizable.  When used in diminishing perspective, it is conventional to place the recognizable element low in the frame, where the foreground and background overlap. 

**** A completely different form of perspective is that of atmospheric haze, which reduces the contrast in distant parts of the scene.  One of the tell-tale signs that an image has had a sky dropped in is lack of that typically paler blue color with low contrast for background elements, including such elements as clouds or mountains along the horizon. 

**** This aerial shot of Zion National Park clearly shows the distant mountain ridge as a low contrast, pale blue color.

**** In another aerial shot, this one of Bryce National Park, the rising sun is causing the atmospheric haze to turn yellow, which is unexpected for many viewers.  As such, it typically holds one’s attention longer than images that appear more ordinary.


**** Fascination with rain, fog and mist is also an issue of atmospheric haze, which can sometimes be used to confuse the viewer’s clues of reference and distance.  UV filters and/or polarizers can reduce haze.  This can be particularly important when using telephoto lenses, because the lens inherently sees more atmospheric haze than wide angle lenses when the subject matter is in the distance. 

**** If you are looking to reduce or enhance atmospheric haze during retouching (especially in B&W images), then consider using the blue channel as a mask for a Curves adjustment.  Personally, I would then group the Curves layer, apply a mask to the group, and then use a gradient tool to selective apply the curves layer to the area where modification to the atmospheric haze is desired.

**** That seems like enough for this podcast.  If you have any comments, please use the Contact button along the top Menu bar of the main website.  And if you would like to show off your work or ask a question, don’t hesitate to Submit an Image, using the Right sidebar button also on the main website.

Thanks for listening and thanks for visiting RickAllenPhoto.com  Until we speak again, this is Rick Allen.

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