Sunday, June 5, 2011

The Religion of Depth of Field

I can't remember when when someone first uttered the term "depth of field," to me in a conversation.  But I remember it sounded holy; it seemed to automatically consecrate it’s speaker to a higher level of filmmaking.

It was intimidating at first; that term you’d smile and nod your head at, pretending you knew precisely what the other filmmaker was talking about.  Then it became that thing you said to sound like you knew what you were talking about.   

Later, after a couple days of looking at the results on the monitor of my first short film, depth of field became the difference between crap and Scorsese.  It was the secret separating the wanabees from the professionals, and if you had it, it gave that image in the frame a quality which separated it from all the other “video” out there.

Back then, it was all about the Red Rock Adapter, and we embraced it in spite of it’s many flaws just for a taste of that shallow depth of field.  Nevermind the inverted image you had to fix in post, or the soft corners of your frame.  Nevermind that depth of field is one variable effect depending on the focal length of the lens you use -- this was a revolution, and shallow DOF was the official religion.

After that came impressive, yet inexpensive camera bodies, the Red with it's vaunted, but unusable 4k resolution, then the DSLRs with 35mm image sensors that can fully utilize cinema prime lenses without cropping any imagery, which is now everything. -- Maybe even more than "depth of field," "35mm" is another one of those holy things that endow a filmmaking product as a must have.

But what does any of it mean?  Depth of field particularly is rarely spoken of in terms of meaning; what it actually achieves, how it can be used, or what it accentuates.  At best it’s all about how pretty it makes the image; or it's just a matter of preference.  How many filmmakers see beyond the bullet on the pamphlet as that fantastic must have feature, or as the thing that will make their film look like a “real” film, and actually see the tool and all the tricks they can do with it?  After all, two films shot at two different focal lengths, are two very different films...

Directors are idolized with the same labels.  Haven't you heard?  The Coen Brothers like using wide lenses, and Michael Bay likes long lenses.  As though the prescription for becoming Tim Burton, is fundamentally determined by the lenses you use.  (Incidentally he likes the 21mm and goes up to 50mm, but never beyond.) 
Cronenberg likes shooting entire films with one lens.  David Lynch is a shallow depth of field, long lens man, while Scorsese prefers wide angle lenses – “25mm and wider” for “crispness, and for a dramatic use of the lines."  Meanwhile Woody Allen likes to use the zoom lens a lot as a means of breaking up a scene without cuts...  All of these filmmakers have reasons they keep coming back to these conventions, why don't we hear more about the reasons?

In the end, it's about the movie.  It's about the story and the images, and how those images are manipulated to achieve amazing effects.  "Was the image sensor a 35mm image sensor?" isn't a really a thought if those images are composed with mastery.  "Depth of field," "35mm," are elements in a greater language.  Use the tools, use them creatively, and tell a story.

Charles Rhoads

1 comment:

  1. Depth Of Field:

    The distance through which elements in an image are in sharp focus. Bright light and a narrow lens aperture tend to produce a larger depth of field, as does using a wide-angle rather than a long lens. A shallow depth of field is often used as a technique to focus audience attention on the most significant aspect of a scene without having to use an analytic cut-in.

    Depth of field is directly connected, but not to be confused, with focus. Focus is the quality (the "sharpness" of an object as it is registered in the image) and depth of field refers to the extent to which the space represented is in focus. For a given lens aperture and level of lighting, the longer the focal distance (the distance between the lens and the object that is in focus) the greater the focal depth. For a given focal distance, the greater the level of lighting or the narrower the aperture, the greater the focal depth. For that reason, close-up shooting and shooting in low light conditions often results in images with very shallow depth of field. An image with shallow depth of field, as this frame from Peking Opera Blues (Do Ma Daan, Tsui Hark , 1986), has some elements in focus, but others are not.