a few questions

Lazlo

New member
First off, this is probobly just a matter of mind vs matter, but what happens when you take a film at a certain ISO, but then rate it differently when shooting? All you're doing is pushing or pulling it right? How much can you you rate it off of its original ISO and still recieve good results?

Also, (I don't know if you'll know this) but what are the responsibilities of the production designer?

Thank you for the time.
 
Exposing and processing are two different things. You can expose normally, underexpose, or overexpose -- and process that normally. You can also pull or push process something normally exposed, overexposed, or underexposed.

Both exposure and processing affect DENSITY, the amount of silver (in b&w) or color dye that is formed.

The manufacturer's recommended exposure index (EI) basically means that if you expose correctly at this rating, and process normally, you should end up with a negative of average density.

But you could change the final density of the negative, which in turn affects the printer lights needed to create a print of normal brightness (or density, again). For example, underexposure leads to the "thin" negative (less dense) that requires lower printer lights to lighten the image back to normal. Overexposure leads to a "thick" or "dense" negative that requires higher printer light numbers to darken the image down to normal in the print. Here I'm talking about normal processing for this under or overexposed negative.

You could also underexpose (would cause a thin negative) and then push-process (extended development) to increase the density back to normal. This is what would happen if you underexposed by one stop and then asked for a one-stop push-process.

You could even overexpose by one stop and then push-process by one stop, ending up with a total of two stops extra density, just as if you had overexposed by two stops and developed normally.

So you see that exposure and processing are two different steps that both affect density. You can alter one, the other, or both.

How far you can over or underexpose, process normally, and then print up or down to restore the image to normal and find this acceptable-looking is a matter of taste. Generally people try to print in the middle of the printer light scale or slightly higher (i.e. expose for a slightly denser negative and then print down.) A thin negative printed up to normal tends to look milker & grainer than a thick negative printed down to normal, which tends to have deeper blacks and richer colors. But within reason, like no more than a stop of overexposure. I often rate a stock 2/3's of a stop slower than recommended and then print down, so I'd be rating a 500 ASA color negative stock at 320 ASA and usually am printing in the mid 30's instead of the high 20's on the printer light scale to get a print of "normal" brightness.

Push-processing tends to increase grain and contrast; pull-processing tends to decrease grain and contrast and also mutes the colors.

Going for a denser-than-normal negative is less necessary when you are shooting negative for scanning or telecine transfer. It mostly benefits negative for printing.
 
Not that I mind answering these basic questions, but a lot of your questions would be answered by spending some time reading a cinematography textbook... I just don't want my answers to be a substitute for serious book learning.

A production designer is basically the chief art director of a movie, responsible for the look of everything photographed and lit by the cinematographer, like sets, locations, etc. The term "production designer" was created by producer David Selznick for art director William Cameron Menzies on "Gone with the Wind" since Selznick felt that Menzies went far beyond the typical art director's work and really designed the entire look of the production.
 

Lazlo

New member
I'm sorry for the basic questions. I hope this questions is a little better. Your patience, it is greatly appreciated. Why would you use HMI lights, when you can just gel tungstens color temperture to match daylight or moonlight, or whatever? It seems like it would be more cost effective to rent some CPT gels than to rent some HMI lights. Thanks.
 
The Full CTB gel that converts a tungsten lamp to daylight cuts two stops of light, plus HMI's are already more power efficient than tungstens. A 575 watt HMI is about as bright as a 2K tungsten ungelled, so you'd have to use something like a 5K tungsten with Full CTB just to get the light output of a 575 watt or 1200 watt HMI.

Some people do use tungstens only for day work, but often they are huge, powerful lamps to create the necessary brightness to match a bigger HMI & natural daylight levels -- you're talking about Dinos, Jumbos, 20K's, etc. BIG expensive tungsten lamps.

Also, if you are working without a generator, then a 1200 watt HMI is about the brightest light you can plug into a 20 amp houshold circuit. So while the lights are more expensive, you may be saving money on the size of the generator.

Plus a big tungsten lamp puts out a lot more heat, which can make a room more uncomfortable.

But some DP's still would rather use only tungstens, not because of the cost, but because they can use them on dimmers or because they think the color is more consistent.
 
K

Kevin_Zanit

Guest
Because HMIs are much more efficient lights than tungsten units.

The output of 4k HMI is greater than a 10k tungsten unit (thus less power consumption).

Also to balance the tungsten units to daylight (using CTB gel) decreases your light output. CTB only transmits 36% of the light. In other words you lose over half your light output (64%).


Kevin Zanit
 

Lazlo

New member
When dealing with non correcting jib arms and cranes, does the grip team automatically know to correct for the inherent arc, or do you have to tell them to correct for it? Also, what has your experience been with jibs, do they make production any easier in terms of speed and efficiency? Thanks.
 
Everyone who has worked with a crane has to consider the arc it makes, or else they will quickly learn. The dolly grip and I will discuss the best place for the crane base, how it will arc, whether we need to track with the base a little to compensate, etc. You'll often see me on the set waving my arm around trying to imagine the arc of the crane arm...

I don't use small jibs too much except when I need to do a high angle looking straight down, like at two people in bed, etc. or need to do a lot of extreme, fast booms in the shot. Otherwise, I find that even the small ones take up a lot of room on the set and it's a lot of weight (a 35mm camera) to teeter-totter on the end of an arm and keep still during the static moments. But some people swear by them and shoot whole movies off the end of a jib arm. They probably work better with remote heads (which is how Roger Deakins uses them) so you aren't putting weight down on the pan handle, etc. when operating.
 

Lazlo

New member
I am sure you have worked with all sorts of directors. How do you come to understand the directors vision if the director talks very little or not at all. This one I will be working with works in that way mostly, and then sort of does his own thing anyways. What questions should I ask to get a deeper understanding, I still want to stay true to his vision, this is just made difficult by the lack of communication. The only time this director talks is when asked questions, and even then the answers are sometimes vague. Thanks.
 
It hasn't happened to me yet so I'll tell you when it does. Most people who can raise thousands if not millions of dollars to make a film do not have a problem talking to you about their movie, unless they simply don't know what they want.
 
K

Kevin_Zanit

Guest
I have worked with directors like that before.

As David said, it could be that they just simply do not know what they want.

Also, sometimes they get a little timid if they are new to being around a decent sized crew; maybe they are a little overwhelmed.

Whatever the reason may be, it can present a very serious problem. The movie could end up lacking vision and a voice. It will cause some confusion as to what is going on if he can't communicate.

After working with a few people like this, I found that if I work extra hard on talking to them about what they want during pre-production it can help, especially if they get quiet on set. After coaxing a dialogue out with the director, he may start to get more comfortable expressing his views on set.


Kevin Zanit
 

Lazlo

New member
I know you probobly have experience in working with HD or other DV formats, and I was wondering how much you rely on a monitor. I have read that even the best still make it difficult to rely on. How safe is it make judgement calls based on what a monitor sees?

I have read that it is a requisite to have a ballast if you are using HMI's, and I don't understand why. What would happen if you tried to run one without a ballast? I don't really understand the purpose of one (ballasts) to tell you the truth.

When have you used (if ever) Xenons on a set? Why wouldn't you just use a fresnel?
 
K

Kevin_Zanit

Guest
When I shoot any video format I tend to like looking at the monitor.

When I shoot film, the monitor is for framing only.

A properly calibrated monitor is very important if you are going to rely on it. It needs to be isolated from light pollution (ambient light), and calibrated more or less everyday.

If I am operating the camera, I tend not to look at the monitor as much for the simple reason that I don't have time to run back and forth all day. Sometimes I will have the 1st AC or director operate on a rehearsal so I can watch monitor if I am curious. This is why I like to use a camera operator on video shoots, but due to budget reasons this is not always possible.

I am able to more or less judge what things look like without a monitor, but if I am changing things up in camera (crushing the black a lot, the knee settings, etc) my ability to do so is diminished.

HMIs require a ballast to work. They need a huge amount of voltage to "strike" the unit, and then they control the voltage that goes to the globe to keep it working.

You can not just plug a HMI into standard power. It takes a "head cable" which is a special multi-pin cable that connects from the ballast to the light, and the ballast is connected to your power source.

I have used Xenon’s (and I know David used them on Northfork). The question you are asking is like "Why use oil, just use watercolors?"

A fresnel and a Xenon unit produce two very different qualities of light. A Xenon is one of the most intense, focused point sources you can get. A 1k Xenon at 20 feet away on 400ASA film gave me an f32 reading. One powerful unit. It is used when you want to create shafts of light through a room filled with smoke (or "atmosphere").

It can be spotted and flooded, but as you do that a dark circle in the center of the beam is formed. You can’t really make hard cuts to the light with a flag (you must use metal flags) because the beam pattern is oddly shaped. The light is extremely hot, thus you have to be careful with gel or anything else you put in front of it. It also can not be oriented in odd positions, thus you use Xenon mirrors with it. It also is fan cooled, thus the noise can present a problem for the sound department. The globes are also EXTREMLY dangerous. They carry an explosion hazard because they are under such high pressures. That is why larger Xenons rent with “flak jackets” and face masks for the person changing the globe if there is a burnout. It is also daylight balanced like an HMI is.

A fresnel is more of a standard unit. It gets its name from its lens, a fresnel lens. You can spot and flood this unit as well. You can get tungsten and daylight balanced fresnels.

Kevin Zanit
 
Most pro video cameras have a b&w viewfinder so a color monitor is fairly important. If set-up properly using color bars, and properly shaded or tented, it should be accurate enough to judge exposure when combined with using the zebras in the viewfinder.

You can get either an HMI or a tungsten lamp with a fresnel lens.

HMI's are AC gas discharge lamps like fluorescents, which also use a ballast. The ballast allows for the high voltage needed to strike and then acts as a regulator (I believe.)
 
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