Well, writing all that explanation helped me really retain that information, so bear with me here. My exam is tomorrow. And maybe you'll learn something. But I'm especially writing this for the Einstein who said it gave him/her a headache.
Where were we? I think we were talking about stops and the double half rule. Great. Let's move over into the fabulous worlds of viewfinders.
A quick history. . . in the past there WERE no viewfinders. Photographers and motion picture cinematographers alike used just wireframes that were mounted on the side or top of their cameras to approximate what they might be filming. But of course, they had to be expert mathematicians to make sure their focus was right (based on measurements) and they especially had to look out for "Parallex" problems - that is, based on the lens and how far you are zoomed in or out (or dollied in or out) the angle of viewing could be vastly different than what your wireframe was framing for you. The solution in this case was to dolly all the way in as close as your coverage of scene was going to get and make sure you are getting the face or item within the frame, and then you know as you dolly out you'll get what you need. But keep in mind when you watch films made in the early 1900s (Citizen Kane, for instance) that the camera operators did not have a proper viewfinder.
There are basically 2 different kind of viewfinders. The first is called the Reflex, or TTL, viewfinder. TTL stands for "Through the Taking Lens" meaning you are seeing what the lens that is filming is actually seeing. It's called a Reflex viewfinder because it is making use of the reflection for the shutter's mirror, which bounces up into a prism which directs it into the viewfinder. The viewfinder on a motion picture camera will actually flicker, as you are only seeing the image when the mirror is covering the film (when the shutter is closed), not when the film is being exposed (when the shutter is open).
Of course, some pesky consumers complained that they didn't like that flicker, so you will find some consumer level cameras that have a "non flicker" Reflex system. They have the light come in through the lens, and then right away it meets a prism which splits that light, sending part of it to the film, and the other part up to the viewfinder's prism. So you do away with the flicker, but you've split the light and thus these cameras require more light to be exposed properly. Personally, I like the flicker, so I think this whole idea is stupid.
Then there is the Non-Reflex Viewing System. You all know the kind -- think disposable cameras. So you can take a picture with your finger over the taking lens but it looks fine to you when you look through the viewing lens. Cameras with this kind of viewing lens would need to have adjustable lines on the viewfinder to approximate the captured image differences between a wide angle taking lens and a telephoto taking lens, and again they run into Parallex Issues, especially as you use a telephoto lens to zoom in.
My conclusion: Through the Taking Lens is the only way to go. Why bother with a lens that just hints at what the film is seeing, but could very well be wrong?
OK, everybody, it's time to talk ASPECT RATIO! In this day and age of widescreen TVs and letterbox DVDs, people are fairly familiar with what this is. Up until 1955, movies were not actually shot widescreen, they were shot like standard television - 1.33 wide for 1 unit high. But then Studios started panicking as TV became more prevalent and feared that noone would come to see movies anymore. So in order to differentiate, they decided to make their films WIDER. 1.85 wide for every 1 unit high. Did they invest in all new equipment and new film stocks and projections to make this happen? No. In fact, movies are still shot on standard 35mm film -- which records to a native 1.33 to 1 aspect ratio. And then, the projectionist puts a matte over the projector that blocks out the top and bottom so you don't see those parts that were filmed. But a good cinematographer will shoot making sure that no boom stands or dolly tracks make it into those "matted out" top and bottom edges - because sometimes in a DVD or video transfer those parts may kind of make it into the print. In Dustin Hoffman's "Marathon Man" you can see an actor's position tape in one scene and a fairly complex dolly track in another.
It's not uncommon these days for a cinematographer to be asked to film a movie or a TV show with 3 different aspect ratios in mind. They know they want 1.85:1 for the Cinematic Release, but they want to be able to show it on cable TV at 1.33:1 and on HD TV, which is 1.78:1. Fun fun.
Some film makers will also try to go Super Wide Screen by using Anamorphic lenses, which actually distort the image to push the aspect ratio to 2.40:1. It's shot on normal 35mm film and it actually looks stretched on the negative, but then when it's projected back the projector will ALSO use an Anamorphic playback lens, and so it will just look Super Wide and not artificially stretched. Approximately 30% of Hollywood Films are shot Anamorphic.
By the way, two nights ago when I discussed Lensmounts? The names of the ones that screw in are called B Mounts (used for 8mm cameras) or C Mounts (used for 16mm cameras, and are more common than B Mounts).
The one that just sticks in and uses the length of the lens to hold it in place? It's called a Bayonet Lensmount. (For obvious reasons).
And the preferred one that is used on most pro level cameras. It's called PL Lensmount - which stands for Positive Lock. It has an advantage because it locks and place, and it's either locked in or it isn't, so there is no Collomation concern (when the lens is too far or too close to the film).
It's time to discuss the Magazine. This is where the film, both exposed and unexposed, is stored.
One kind of Magazine is the Displacement Style. Here the film is all held in one chamber, with the exposed film reeled up on the "take-up" side and the unexposed (Raw Stock) stored in the "Take up side." In a displacement style magazine, film must be loaded AND unloaded in complete darkness (a dark room, a changing bag, a changing tent).
Then there is the Dual Compartment magazine, which has 2 airtight chambers that are separate from each other. Because of this, you have to unload the take up side in total darkness, but the feed side can be loaded in light. (You just expose the small amount of film needed to thread through the camera).
As documentary filmmaking took off in popularity and quick changes were needed since action was not planned and one needed to be ready at all time, a new kind of Magazine was developed. The Coaxial Magazine is a quick change magazine that can be loaded completely separate from the camera and then easily added on when needed. All threading takes place within the coaxial chamber.
Panavision will just use Displacement magazines. Arri will use Displacement and Dual Compartment. With some cameras, the camera body itself is also the magazine. The Bolex, for example, is set up this way. (As are most still cameras).
So you've probably used it and never given two thoughts about it. Film stock. Just what is it made up of and how does it reproduce images?
The secret is a naturally occurring material called Silver Halide. Well over 100 years ago, it was discovered to be reactive to light, and would arrange itself according to the light that hit it. However, Silver Halide itself is just a very fine powder, so in order to make it usable, it must be mixed with something.
It is mixed with a binder, which works as a fortifier and turns it into something that can be applied as a layer -- a photographic emulsion.
So, Silver Halide mixed with gelatin (which is used as the binder) is your photographic emulsion. Yes, gelatin, the same used in Jell-O. The same gelatin, which is an awfully nice word for "ground up pig and cow bones."
And this is where, if you are a vegetarian or a vegan, you might want to skip ahead a couple hundred words. I''m warning you. Because it is a little publicized fact that all film consists of gelatin. So, Vegetarians cannot in good conscience make or WATCH motion picture films, at least that's how I see it. For every "Die Hard 2" hundreds of cows had to be placed in a blender. There's no way around it.
The photograph emulsion is still not the film, it's just a very thin layer that needs support, called a base. Back in the beginning of photographic technology, people would use glass as the base. However, glass would not work. It's not flexible and can't move through the camera. What is used now is plastic, which provides the ability to transport the emulsion and support for it.
The tan side is the emulsion. The black side is the base. Most of the thickness of film is the base. A layer of photographic emulsion is only 1/10th of the width of a human hair. Very thin.
Interestingly, until the 1940s, people used Nitrate for the base of film. Explosive, volatile Nitrate. And if it came in contact with a flame, it was like dynamite. This is why projectionist booths have such tiny windows - for the safety of the audience in case the film exploded. Sadly, Nitrate breaks down quickly, and half the films made prior to the 1950 no longer exist in any form. (This is partly the fault of the Studios too, who saw no value in preserving films once they were finished their theatrical run, not having the foresight for such things as DVDs and VCRs and re-releases. The film was released, ended it's presentation, and then had no worth.)
The actual breakdown of film is as follows (from top to bottom): Layer of clear protective coating. Photograph Emulsion(s), Subbing layer (glue that sticks the emulsion to the base), Plastic Base, Anti-Halation Backing.
The Anti-Halation backing is a layer that protects against light bouncing off the pressure plate which was behind the film and exposing it again. In old movies you'll see an odd halo effect often, and this was prior to use of the Anti-Halation backing.
Color Film will actually have multiple layers (6) of photographic emulsion (each for a different color), and because of this is slightly thicker than black and white film. This can actually be a problem when shooting in black and white, because that slightly thinner film can lead to more frequent camera jams AND can buildup static electricity which will show up in the print as tiny exposed lightning patterns. When Spielberg shot Schindler's List this was a huge problem they had to overcome.
Motion Film camera comes in 2 basic types: Positive/Negative and Reversal Film.
Positive/Negative is like your common still film, it develops as a negative image and you can create a positive image using that negative.
Reversal film is more akin to Slide Film. The Camera Original film is also the Positive Print. There is no negative involved.
Since you only have to develop it once, Reversal film is less expensive, and it was developed for consumer use. The contrast on it is higher and it's sensitivity to dark and lights is very high and it can get blown out or blacked out more quickly then convential positive/negative film. The color reproduction is also slightly unreal. All of this can be used to great effect, as when Spike Lee shot Clockers or in the film U-Turn.
THE CHARACTERISTICS OF A FILM STOCK
Just like in still photography, you have your Exposure Index, also known as the ISO, the ASA, the EI, the film speed. The higher this number, the greater sensitivity the film has to the light.
A very important concept is understanding film stocks is the film's Latitude, which is it's ability to record a range of exposure from bright to dark. How light and how dark can the room be and still make out detail? The human eye has a tremendous latitude, and can make out detail on both extremely bright and extremely dark spaces. Motion picture film's latitude is a subset of the human eye's ability. So the Cinematographer's job is to translate what people know as a large latitude space into a much more limited, compressed latitude (that of film).
They will do this by using lights to move more shadows into a film stock's latitude. These are called Fill Lights, and if not used those shadows would be deep dark shadows (otherwise known as bulletproof blacks). The X-Files often purposely exceeded the latitude towards the bright end of the spectrum to completely blow out the windows so you couldn't see anything through them but blindingly bright light streaming into a dark set.
Another characteristic is the film stocks' contrast - the ability to reproduce shades of grey in tonality. High contrast will see lots of bright whites and dark blacks, low contrast will produce lots of shades of grey. Shooting in the morning will naturally produce lower contrast, and shooting in the afternoon will naturally produce high contrast.
There are ONLY TWO producers of motion picture film stock. Kodak and Fuji. Kodak inherently has more contrast. And Fuji has less contrast. So, for instance, if you had to shoot in the afternoon, but needed to make it look like morning, it would be smart to use Fuji film for that particular shoot.
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Sorry all. . .. That's as far as I can get here. I have to get to bed soon.