What goes into the lens choice?
 

I've often wondered how and why cinematographers and directors come together and choose the lens they do for a given scene.

Is there a book out there, geared toward aspiring directors, (read that as in lay terms) on how to choose the right lens?

I took the cinematographers word for it but when I'm sitting in the room with the editor and he says, "What's up with your lens choice here? I can't use this."

I'm stumped. I want to be a director, I should know these things.

Any help would be appreciated.

Lens choice is related to the geometry of the image and prespective. Perspective deals with the relative sizes of objects within the frame. Imagine two characters shouting at each other - the relative sizes of each character compared to the other can be a dramatic element in the psychological impact of the scene where rendering one character larger on the screen than the other can convey a silent message about who is really dominant, who is really stronger, etc. that perhaps even runs counter to what the dialog is saying. The visual perspective relationships between the various objects in the scene sends the audience information to advance the storyline just as does costume, dialog, pacing, music, etc. And finally the spatial relationships go into making a picture visually interesting or boring. suggest stability or dynamic situations, etc. Size relationships in the frame are part and parcel of the vocabulary and grammar of any visual language be it oil painting, still photography, or film and video. It even appears in stage production where Bob Fosse once described dance as a sequence of still images, a series of sculptural compositions flowing one into another.

So how does this influence lens choice? Perspective rendering, the spatial relationship of the objects within the frame, is determined by the position of the camera with respect to the scene - the farther away you are, the "flatter" the scene will appear while close camera positions emphasize the differences between near and far objects. The lens focal length then determines the overall size of the image - the amount of the scene included in the frame or excluded lying outside the frame. So the basic sequence is a: decide on the camera direction that composes the characters with relation to each other and the background; b: choose a camera distance and height that renders perspective the way you want it; c: decide on a lens focal length that crops the image to include just the visual elements you want to have in-frame; and d: select a focal point and if possible an iris that renders the portions of the frame you want to be in focus sharply and lets other parts go soft if desired. The camera position and the sizes of objects in the frame, ie, the lens choice when filming, then become part of the editiing descisions in maintaining continuity of the scene so one shot cuts well into another and the scene flows seamlessly.

that was a nice summary of cinematography. to expound on one point, the longer the lens, the closer background objects will appear to be, a la the mountain range in 'shane'. conversely, a wider lens will make background objects appear further away. lens choice plays a big role in creative frame composition. it's all about what you want your audience to see... and proper lens choices will give you the flexibility to deliver exactly that.

Thanks Steve and Henry, that clears a lot of things up. Is there a book or a web site that shows all the differenct lenses and how they look and maybe something on how/why they're used.

there are a lot of resources on the web for this, and a simple google search will probably heap you with tons of reading info. keep in mind most of the principles of still photography lenses will also apply to film/video lenses, tho equivalent focal length measurements will differ going from still lenses to video lenses.

when i was in film school (two decades ago!), i remember my favorite books weren't the technical ones, but the ones that went into the subjective art and technique of cinematographers. i still wish i had some of those books, but my favorites included dennis shaefer's 'masters of light' and nestor almendros' 'a man with a camera'. less about the what, more about the why.

anyways, good luck in your directing pursuit...

The same principals of perspective control and lens choice apply to both still and moving images. A couple of excellent discussions with visual examples are found in Ansel Adams "The Camera" and "The Negative" and the now ancient but perhaps available at your public library Time-Life series on photography.

I have been wondering the exact same thing, i just never knew how to phrase my question.

Interesting how i learn more things about filming and it's basics and advanced sides from digging and listening myself then when i am at the classes in school. I read a book recently which pretty much summed two years of badly explained courses into a two day read, and much more.

@ Steve and Henry: Thanks I'll check those out.

@ Dan Bergqvist: What was the book Dan? And is it printed in english?

Back in the day when news was on 16mm, we tried to keep lenses only as far as 15mm or 25mm apart. Didnt want to get caught without a wide lens or a closeup. Now, with Zoom Cinema lenses, we try to cover all mm measurments upto 210 or 300.

Brand usually goes by preference now, or by who's king. Canon and Fuji are the debate for ENG - Canon is the long player, but Fuji is equally good with cheaper prices. Agneiux and such make decent lenses but not popular in the U.S.

Zeiss seems to be th boss for Digital cinema, and the Fuji and Canon digital primes

JmhO