Tuesday is the day to get sound checks performed in each room.
During the first minute of the Faces DCP, the screen shows a black background with a blue bar going across the middle. After a while the black background goes grey on one side. You’ll notice when you look at the two ends of the blue bar now that they look different – one more solid blue, one softer. When the background goes solid black, the bar looks solid blue from end to end again.
When we walk into the auditorium to do our task attempt to judge whether the picture quality in an auditorium is correct, we have to be aware that the Human Visual System can be tricked.
Perhaps that is the wrong way to say it. In fact, the Human Visual System uses tricks to get around the limitations that it has. One example is the number of color sensors we have in the eye. For many reasons, we have 100 million sensors squeezed onto the inside of each eyeball. But only about 6 million are sensitive to color. On average, 4 million are sensitive to red light, 2 million to green light, and only a few hundred thousand are sensitive to blue light.
The major idea behind the two Faces Test DCPs is that the Human Visual System and the Human Hearing System work magic. To test the picture in your auditoriums, we have to somehow get around that magic.
One part of the magic is that people’s eyes adjust to different light levels. We have the ability to see in dark moonlight and in bright sunlight. We can see great detail in our center vision, and we can see minute motion in our side vision. The eyes and the brain work together to give the best image possible in different circumstances.
We hear sound in a similar way. In a quiet room we can here a fan or even a mosquito that is 3 meters (10 feet) away. In a loud kitchen, we can hear voices that are softer than the loud pots and pans. (Well, sometimes.) We certainly can’t hear that mosquito among the kitchen noises. And we can’t see a dark cat go by in the shadows if there are headlights making the the scene too bright.
Usually this magic is a great thing. It is an automatic process that protects the eyes, yet lets us see through an incredible range of light in the right circumstances. But it also means that when we see leaves of green and fields of rice waving in the wind, we presume that the clouds are white and the sky is blue …but they might really be grayish white and a light shade of blue.
This especially happens in a movie theater. The sun or reflections that we see outside are hundreds, even thousands of times brighter than a projector can display on the screen. Yet, we believe it is bright white. And that is what matters to the audience. But we have to check that the projection system is giving all that can be expected, not wimping out or giving too much of one color or not enough of another.
Sound is the same way. It is a rare person who can hear a tone and accurately say with certainty, “That is the note ‘E’ below middle ‘C’ on the piano for example or that it is soft or loud. All we can say is that it is soft or loud in comparison to something else.
Our purpose is to test the system, to see if it has the right amount of light (and sound). How do we get around this amazing capability of the Human Visual and Hearing Systems?
One thing that people can do very well is determine if faces look right. So, your author went to a photo sharing site and dropped a bunch of faces on top of each other and made two DCPs. We think it turned out to be a very interesting way for you to judge the quality the projected pictures on your screen. And, like the other DCPs, there are also clean and distorted and muted high and low notes to judge the quality of your sound. Oh~! and let’s not forget the subtitles…
The passcode is QA_b4_QC
Here is a quicktime version of the Faces1 DCP – Have fun, and tell us what you think. With your help we can make a system that helps you tell the tech what is wrong and eliminates the complaints of the audience member.
If you get some answer wrong, review the material. Look for the concept immediately before the information to find your area of confusion. Is there some phrase you still aren’t comfortable with? Some word not understood in the way it is used? There is no hurry here – discuss it in the forums or the comments …or even send an email if you want to deal with the problem privately.
There is a rule in technology. Engineering is the Art of Compromise.
This rule applies to the sound as well as to the picture. It applies to the equipment that creates sound and picture. It applies to safety equipment and the carpet that we walk on.
It means that there is always a trade to make between speed or size or cost or portability, or the push to be the greatest, and especially if we try to be the cheapest.
Maybe you want more light on the screen. But that will give you more scattered light too, all over the ceiling and sidewalls, and that is not a good thing. Or you think, OK, I won’t let it scatter, I’ll direct the light using curved screens and screens of different materials. But directing light will bring you ‘hot spots’ and that can be worse.
We are surrounded by the decisions of designers who have to balance these things everywhere in our daily lives.
There are machines, tools really, that will test light and sound. They are usually very expensive, and they require very trained people to set them up and use them properly. These people must then take the tests properly and then read the results properly. So, it isn’t only that the equipment costs 15,000 to 30,000 dollars or euros. They also consume expensive technician time.
So, that is the trade-off, the compromise. We can make the projector and screen perfectly calibrated every week, or month, or 3 months or 6 or 12. We just have to pay for it and the people to run the equipment.
Welcome to Part II of A Look At Light. Click this link for Part I
We work on the theory that a large percentage of people who get a job at a cinema do so to get an entry into Entertainment Technology. Shhh…It’s OK; we won’t tell anyone.
Entertainment technology is quite interesting and has been very good to a lot of fun people. Just don’t tell anyone that training you is all that we are really interested in. The industry needs interested and interesting people. Start out being interested about everything and soon you will be interesting.
There is nothing wrong with someone just taking a gig because you need the cash, or any other reason, of course. But, if you are interested in how all of the equipment around you turned from ideas into reality, keep doing well.
What does that all have to do with The Emergency?
Well, unfortunately, with more knowledge comes more responsibility. And no matter how one may try to prevent panic-inducing moments, sometimes they will happen.
At that moment it is knowledge and practice that needs to kick in. To panic gracefully when others around you are stunned or reaching the wrong conclusion about what happened or what needs to be done.
That is the point of this Series. Is the equipment in shape? What equipment? There’s a list somewhere right? Has it been tested, has it gone passed some due date even when its valve shows it is in the green?
This article is unfinished, waiting for someone with the time and ideas to put the finishing touches on…is that you?
Hi again. This is a work-in-progress…do not read yet.
At the very end of Audio (Sound Basics), Part 2 we introduced the concept of Frequency when discussing waves. We also mentioned some basic information about the speakers in the room, which create the waves that we eventually hear. This article will build from there. You can skip all of this and you can still talk to a technician, but it is really simple. It just looks long because there are a lot of examples.<!–more–>
It was said that we can think of sound like the waves made by a falling pebble on the surface of a pond. This isn’t exactly true, but that is the trouble with analogies – they are similar by not exact. At least you can see a wave in water. A sound wave, not so much. So, we’ll proceed with this analogy as far as we can and explain the difference later. Because we have to learn about sound, and sound is made of waves that are created by the speakers.
So, the experiment is dropping a marble in a pond from the same height each time. If we look closely at the expanding waves, we will notice that the first wave is always taller. As the wave moves away from the source point it gets shorter and shorter. But, while we can see it, the distance from the peak of one wave to the peak of the next stays the same.
What we are seeing is that the power is getting distributed around the water in the circle, so the height goes down. But while it was happening, the number of waves going past the place you were looking at was constant. If we could look while also measuring time, we would notice that the number of waves that go past in the first 5 seconds is the same number of waves that go past in the next 5 seconds.
The distance between the peaks of the waves is called the Wavelength. The number of waves every minute or waves per second is called the Frequency. These two are completely related – as the number of one goes higher, the number of the other goes lower. The higher the Frequency – that is, the number of waves going past per second or minute – the shorter the peak-to-peak Wavelength. And, the opposite; the lower the frequency, the wave length is longer.
An easier example of these opposites is waves at the beach. If we see them crashing to the shore at 15 a minute, we can probably look into the distance and see several waves coming in. (High frequency, short wavelength.) But if you see the surfer who has to stand on her board to see the next wave – that is, the peaks are very distant, that means they have a long wavelength, and sure enough, there is a low frequency – you will see that there are only a few waves per minute crashing on the shore.
You can almost see this with a piano or guitar or harp string. When the low note is hit or picked, the string travels back and forth so slowly that you can practically see it (although, no matter how fast I can count, I can’t keep up.) But the actual sound wave that it is generating is very long. For example, the low note on the piano moves back and forth 27.5 times every second – we say 27.5 cycles per second. The wavelength – and you’ll just have to believe the science people on this – is over 10 meters long…over 33 feet!
And, here is the important part – you can pound on that note hard or soft, but the frequency of the strings and the sound will be the same…and the wavelength will be the same! And the same is true of a high frequency note, which might have a wavelength of only 6 inches (.15 meter), and a frequency of 2,500 cycles per second.
So, let’d end Part 2 here. Just one more silly thing.
Mr. and Mr. Hertz raised a very clever son who figured out that the theories of a very clever guy from Scotland named Maxwell were probable. The theories were about electricity and magnetism in a time when they were both considered spooky actions at a distance. It was a classic example of what Issac Asimov meant when he said “Any sufficiently advanced technology is indistinguishable from magic.” Anyway, his work was all about understanding waves and you will hear (or read) “cycles per second” called Hertz (abbreviated ‘Hz’), or kilohertz (kHz is the formal abbreviation, but the slang abbreviation is just ‘k’ – so you’ll hear, “The explosion had no sound above 1k”, meaning, there were no high frequencies above 1,000 Hz (kilo- means ‘thousand’)
Next we will tie these all together, add a little power and figure out what these terms have to do with your auditorium.
If we hit a bell with a hammer, it goes ‘bong’ or rings with a high pitch, depending on how it was made. If we feel the bell while it rings we can feel it vibrating back and forth just like the guitar string.
In and out, not up and down.
The height of is not the frequency of the wave. The height shows the power of the wave – the force of the energy that is expanding outward from the source point. The frequency is the number of waves that go by a certain point in a particular length of time. The frequency can be the same even if the waves are taller or shortLike the piano strings or a guitar string being struck, we measure sound in wave cycles per second. In this case it is like the water wave, a cycle is measured from the when that top of a wave passes a point until the next top of the wave. If our eyes were able to see the string move as it goes back and forth, it would be a complete cycle from left to right to left again.
When we talk about sound waves, we talk about power as intensity or volume – how loud something is. And that is where we start talking about the son of Mr. and Mrs. Bell.
Basics: Audio (Sound). It is good to have a basic understanding of frequencies and speakers and surround and amplifiers and level and Loudness.
Frequency is a term used when describing both sound and light, so we will need to get a good idea of it. Sound frequencies are very easy to think of when we consider a musical instrument like the piano. From left to right, the notes start with bass and
There are two reasons for this: power and clarity.
Power is simple. The auditorium is large and the sound must get to all of the audience without being too soft for some and without being too loud for others.
In Part 1 of the Contrast Lesson, a simple definition was introduced, with a few examples. Then you were requested to notice details in bright light and shadows while you live life.
Because there is a difference between what we perceive and what we are aware of. Your job as a professional-in-training is, 1) to learn how to be aware of things that you already perceive, then 2) how to communicate well when things are not as good as they should be.
We don’t think about it, but most of our vision is out of focus and not colored. Take a moment to observe: While you focus on this page, much of everything else is very out of focus, and most everything is greyish. You can still see movement if it happens – even in the out of focus areas. You can even tell the direction of a movement. [Sound is similar; while concentrating on something, non-important sounds get ignored, just part of the background, but an urgent noise will be noticed quickly, and with very precise location.]
We are constantly perceiving, even if we are not paying attention to something.
When our eyes blink, we rarely notice – but part of our vision went black for a while! How can we not notice that? When we see someone sitting at the table, we rarely notice the variations of color on their pants or their socks or their shoes. We glance and see the shoes as red. But if we look closely we actually see that the color might be dozens of shades of bright and dark red. If they are in shadows, that red is mostly dark, and some parts might actually be black.
The same shading is happening on the movie screen when you look at it…or at least it should be. If it isn’t, there probably is a problem. Your customers may not know what is wrong, but they will have a feeling that something is wrong. If it is irritating they may just not come back, even if they can’t describe it.
Sometimes you go in to check the picture only to get sucked into the movie and forget to stare at the dark or bright parts of the scene. These are the parts that will inform you if the equipment is working well. There should be detail in the bright – soft shades of colors – and most importantly, there should be exquisite detail in the dark.
So, trick number one. Don’t forget what you are looking for. Trick number 2…Look. Trick number 3: Become better at being aware of what you see…difficult at first but wonderful when you get used to it.
There is a technical way to measure light. If you promise not to laugh, we’ll tell you that it is based upon the light of one candle. All that stuff in Lesson 1 was true.
The term is candela and the measurement for the reflected light from the screen answers the question of “How many candles of light does it take to make the eyes perceive bright white.
The answer is: 48. 48 what? 48 candela per square meter.
Oh my. What is a square meter?
A meter is one of those obscure things for Americans, but very common every place else in the world. And, a square meter is even more odd. Let’s walk through this.
Put your arms out in front of you with your hands flat, facing down. Now, keeping your hands flat and at shoulder level, bring them toward the front of your neck and place the ends of your middle fingers together. Your arms make almost a straight line now. From elbow to elbow is about a meter. Some people will have a shorter distance, some a longer. Doesn’t matter for this purpose. Imagine that length at the bottom of the movie screen. Imagine the sides of a square going up the screen, but only for the same distance. The box with all those equal sides is about a square meter.
Imagine that only that square meter of screen will reflect light…the rest of the screen is dark and actually eats light.
Now, imagine a candle in a dark room shining on your square meter of screen. Put your imaginary candle one meter away from the screen. The light reflects back to you. That is one candela of light per square meter. And that, friends, is also Luminance. And luminance is what technicians measure off the screen with their fancy equipment.
And, if you want to be really cool, if you want to use the word that directors and cinematographers and colorists use, say ‘nits’. “Yeah; the screen is 48 nits…I saw them shoot it with the meter.”
Back to Contrast
Who cares? The picture is on the screen, the sound is hot, the popcorn didn’t burn this morning…all is good.
And maybe it is.
In a perfect world the contrast is the range or difference between what looks like white and what looks like black on the screen.
In most auditoriums, there is no real white on the screen or real black on the screen. There are many reasons for this, and it will always be this way. Even the most fancy DolbyVision, or Laser IMAX or Sony or Samsung LED wall doesn’t have as much light as a foggy day. But that is a lesson for another time.
There is a range that each room is capable of, and the equipment is in a war to try to make it stable …which it always loses. A bulb gets weaker, electronics get too hot or finds some other reason to fail. The screen material gets darker every week and month and year as it ages – and yellowish instead of whiteish – and sometimes computers just don’t talk to other equipment correctly.
Since it is your job to ensure quality, it is your job to decide whether contrast has reached a point of concern. So, it is time to learn how to judge it. Here are some examples.
When you see someone’s leg under a table or something in a shadow during a movie, you have an opportunity to “See Into The Dark”. At worst, you won’t even see that a black shoe isn’t part of the shadow. At best, you will see that there are different shades of black and grey in the shoe and sock and the pant cuff and the folds in the pants. Notice these things in real life, notice how there is a constant gradient in dark shadows, and how a colored floor will go off to black in the distance.
The opposite will happen in the brilliant whites and colors. There will be ‘blown out’ white where things are not distinguishable at all…just one flat and too-bright-to-look-at white. The funny thing is, the brightest that the very best projector and screen combination can create is 108 units of light, and most strain themselves to create half that.
[Remember from the lesson above: The standard is 48 candela per square meter, which again, simply means: the amount of light that would be created if you held 48 candles at a distance of one meter (3 feet) in front of the screen, then measured all the light reflecting from one square meter of the screen (which is about nine, almost 10 square feet).]
Outside, 100 units are nearly nothing. The reflection of the sun on a car is thousands and thousands of units. (Perhaps we should stop saying ‘units’ since we know that people in the industry call that unit of light a ‘nit’. Just don’t get confused when a tech uses an older term like Foot-Lamberts. 48 nits…48 candela per square meter is equal to 14 foot-lamberts. And yes, it was named after Mr. and Mrs. Lambert’s son. He was famous for a lot of things.)
On-screen, look at some bright part of the sky or something flat and nearly one color – a refrigerator, for example, or even a close up a white dog. The white should actually be many shades of white. You’ll see that this is true of a real dog, or a real sky, and the same is on screen: One solid, flat color is wrong (except in a cartoon!) A smooth gradient of white to lighter or darker white, or another color is correct. There will be shadows in the hairs of the close up of that white dog as well.
So, that is your task. Learn about Contrast by looking: What looks natural in real life and on screen. At first you will write to the tech and say, “In auditorium 5, it really seems like something is wrong in the shadows, but I don’t know what…it is better in the other rooms.” As your abilities grow you’ll be able to say, “The gradient in the darks is off in auditorium 5, they get muddy too quickly. The blues especially seem wrong…it seems like the yellows go toward the brown instead of toward the greens.” Won’t that be fun?
Do well and enjoy the ride.
There’s a funny thing on the internet that lets people in public service jobs know how to deal with those who are disabled – those poor disabled people who have no ability to use Braille or sign language in this case!
“Sighted people tend to be very proud and will not ask directly for assistance. Be gentle, yet firm.”
“Calmly alert the sighted person to his or her surroundings by speaking slowly, in a normal tone of voice. There is no need to raise your voice when addressing a sighted person.”
OK; jokes aside. We are in a service business, and we get a lot of practice dealing with people who can walk strait to the proper line without assistance, but we don’t get a lot of practice dealing with people who need different kinds of assistance.
Does that blind person get a benefit from using Closed Caption equipment? Uhm…probably not. Audio Description equipment? Yes! Probably, yes. Should you ask? Good idea. Continue reading “The Other-Abled, and You”
Intention: Provide materials which can help a technical or non-technical person judge changes in picture and sound quality without the use of meters.
If the test equipment isn’t scheduled at the auditorium for another 6 months, is there a way to tell if the the contrast and color display is degrading? These TIFF slides are experiments to answer this question, and supply tools if it is possible. Suggestions are welcome. All these TIFF plates are 4096 x 2160, 2020 color space with 16 bits of depthiness, unless otherwise mentioned. Sound files from the DCPs will get their own page, but don’t go looking for it now…
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White2Black Dials This TIFF started as an experiment in seeing smoothness from 100 to 0 all over the screen. Really, it was striking as a color print so the logical extreme was black to white everywhere. There are 3 versions in the set, each pushing the center point of the gradient just a little to one side or the other from center. Confuse them at your own risk. And for each one there is a version with a dial. When you make your DCP, use one after the other so the talent can make a judgement without the dials, then mark down the place where any problem exists. The dials on the TIFF files look much better than what is compressed here. Please give them a try, and let us know. As Always, 16 bit, 2020 and the Passcode is QA_b4_QC
Primary and Secondary Dials These radial dials are an experiment to see if broken or funky gradients can be observed or perhaps even be seen gradually going odd over time. As Always, 16 bit, 2020 and the Passcode is QA_b4_QC
4 Colors, 10 Boxes TIFFs Once more, an attempt to see what can be seen in HDR / EXR projector systems, then to find which ones can be used to notice any degradation in the system. These would be the normal SMPTE required RP 431-2 set of blocks going across, but they also have a smooth gradient going across the bottom. …and, they don’t start at 100%. There are 3 sets, one which starts at 10% luminance and goes to 1%, another from 1% to 0.1, and – you guessed it, the 3rd set goes from 0.1% to 0.01%. Thus, with 65,535 as 16 bits, the range of these goes from 6,553 to 7 units of color. More specifics at the download page… For some reason, I made a Rec 709 PNG at 6554 – 655 with outline and it doesn’t seem to show on the computer screen. Well, just a bit if you look sharp. So, this is the 4th of this series, attempting to find an objective measurement technique to quantify changes. The link above gives you a set of TIFFs. And at this link (soon as it is made), there is a DCP. Let me know what works please.
Vertical Meters TIFFs The question for these slides is “Can you objectively and consistently judge where the color ends and only black exists”? Will several people see the same ending point. The underlying question is can the meters be used as tools to objectively judge contrast? If there is a lot of dust on the port window or in the room, will there be a difference? On each slide there are 16 bars of color, 8 starting at 5% luminance in the center and going to 0% at top and bottom, and 8 going from 2.5% and going to 0%. One the left is a set of 4 of each for RGB and White on the left, and the right side is a complete set, through in a different order. The idea was to see if a bright color like green made it too hard to judge the blue if they were adjacent. Indeed, these are experimental. In addition to 5/2.5, there is also a slide with 2.5% and 1% meters, and for those with an extraordinary system, 1% to o.1%. Is 5% a usable meter for each color or is 2.5% more useful in a xenon powered room? The theory is that one can look at the meter and make a substantially objective judgment, record it on one of the checklists, and use the test again a week or month later to note if there are changes. Wow! This PNG only begins to show a usable scale…download the TIFF file.
Dials for Contrast: 6%, 4.5%, 3%, 1.5% RGB and Greys, with and without tic marks. This idea is similar to the vertical meters above, but as dials with the gradient from 6% to 0% (as well as 4.5% and 3% and 1.5% to 0) on a dial, and in several colors. There is a version with a set of tic marks to note where the last point of seeable color is…and a version without. Why? Because it may be that one needs to spot the position of where the color disappears, without the influence of the dial markings, then get the markings later. In the DCP the dials show for 5 seconds then the dials with the tic marks and numbers show together for 5 seconds. Experiment and report please. RGB and Greys. 2020. 4K and 16 bits of depth for each color. All to see if we can get an objective tool that an interested and intelligent person can use. A little trouble making a file that shows on the screen at such low luminance. Try the TIFFs.
Grey Steps with Dirty Numbers The classic row of grey boxes is defined in SMPTE RP 431-2: D-Cinema Quality – Reference Projector and Environment document. One row in the center of the screen. Problem is, it isn’t a very good test of a modern digital cinema projector, is it? This TIFF file has every square of grey from 2.5% to 100%, plus a ramp from 2.5% to 0%. And above that is a set of numbers, that give the luminance value of the square…but it gives it 3 times, and the digits are in three different values. The bottom value is 1% lower, and the middle is 0.1% lower and the top number…hopefully able to be seen in that fancy million to one system, is 0.01% different. The trick is to see if these numbers show up on a screen. Have fun and do share your thoughts. As always, 2020 color space and 16 bits of depthiness. The DCP is at: GreyStepScales These are the numbers that are laid on top of the squares…can your system produce differences for some or most of them?
2117 5 Percent Solution These Dots are made for testing. These two TIFF files are one for Scope and one for Flat with the dots placed on a 5%W line as specified in 296M. Have fun and do share your thoughts. As always, 2020 color space and 16 bits of depthiness. More info is on the actual download site.
2117 Test Plates 1a These Dots are made for testing. First to check that they are usable, and 2nd for putting on the front screen and testing for luminance without glare. There are two sized dots, 10% and 20% of height. They sit on a rectangle that is 15% in from the edges of the Flat or Scope screen. There are 4 type of TIFF files for each Flat and Scope, two 10% and two 20% but one each for 1.90 Full Frame and one each for 2.39 Scope (top and bottom cropped off for a 1716 pixel height) and a 1.85 Flat (with the edges cut off for a 3996 width.) As always, 2020 color space and 16 bits of depthiness.
Primary and Secondary Trumpets Each of these components will be made available in a kit, but for right now, here they are in one chart.
Mach Band Effect Testing Plates There is a whole series to download here. These were developed to learn whether the black of the masking curtains and the typical vignette of the picture cause the illusion of luminance shift.
Horizontal and Vertical Lines – Black, against backgrounds, 2020, 4K Black lines at every other position on the grid…and a variety of different primary and secondary backgrounds.
Horizontal and Vertical Lines – Colored Lines, 2020, 4K What is the difference to a projector or a LED wall between drawn black lines and backgrounds of colors…which actually fill in the alternate lines, right? …and drawing the colors as the lines and letting the editing program put in the background…or no background at all. You too can find out with these plates.
Color Plates, 2020, 4K Primary and secondary color plates – Don’t need pictures of those here, do you? Just get them at the download site.
2 Percent Hmmm – What shall we call this? It is derived from the CST chart that marks off 2% rectangles to begin with, and a bunch of circles drawn at the proper 10% points…then it got botched up with moving the color wheels to align with the corner to corner lines which actually serve no purpose…ok, toss in some focus squares …that’ll distract them. (This png is 709…get the real thing in 2020 and tell us how to make it better please.
2 Percent, Black and White Hmmm – What shall we call this? It was inspired by/is derived from, the CST chart that marks off 2% rectangles to begin with, and a bunch of circles drawn at the proper 10% points…then it got botched up with moving the color wheels to align with the corner to corner lines which actually serve no purpose…ok, toss in some focus squares …that’ll distract them. (This png is 709…get the real thing in 2020 and tell us how to make it better please.
CJ’s Favorite Distraction Several variations with several colors going from full saturation to dark or white …and grey level tests too. A distraction because I keep refining it. Now with MTF marks – hope they work…haven’t tested them yet.
Trumpets 8 TIFFs of Trumpets. The ability to watch as lines get closer together. There are many variations…there are numbers in there somewhere. Experiment and report please. RGB and Black. 2020. 4K and 16 bits of depth for each color. All to see if we can get a subjective objective.
Circles and Stars Circles and Stars and a few other things to stare at. And some fun while making the primaries turn into secondaries. Ya gotta love bluey yellow, no? The alternative TIFF uses outlines of the Siemens Stars for the center position, just to see what detail they hold. No idea if a 4K system can hold 48 spokes…let us know what you find please. RGB and Black. 2020. 4K and 16 bits of depth for each color.
Coming….Colors, Stripes, Dials, MoreMTF –
Scope or Flat can best be shown with some examples of how it goes wrong. These drawings were made because exactly this problem happened in a local screening room for a movie screening to a room full of experts.
The intention isn’t to make fun of anyone, of course. These things happen by mistake more often than by negligence or bad repair. The screening company representative said that there was a run-through previous to the showing and everything was fine. Since she left the room after her welcome statement, we don’t know if what we saw is what she saw previously. It is possible that she didn’t know what to look or listen for, which is exactly why we need to document this. This Lesson will help you to understand this situation, recognize it right away as you do your auditorium inspections…and fix it right away. Continue reading “10b) What Does It Mean: Scope and Flat? Part 2”
Let’s start with something that we will hear about all the time.
A DCP is a Digital Cinema Package. You will never hear, “Did we get the Digital Cinema Package?”. No one will ever say, “Will you play my independent movie please? I can send you the Digital Cinema Package.” No. Instead, they will say, “We got the DCPs.” Or, “I’ll send you the DCP on a hard disk.”
Yes, it is digital, and it is cinema. Digital simply means that is capable of being used by a computer. In case you are not certain, the projector, and the media player for the projector, and sound system are basically just specialized computers. Cinema, of course, means that it has something to do with motion pictures, usually in an auditorium. (The word “cinema” hasn’t had a long life, only about 100 years. The originators of modern motion pictures, the Lumiere brothers, chose the word from the Greek word from Ancient Greek word kínēma – which means “movement”.)
The reason the DCP is called a package is that it holds all the frames of the movie, plus all the music, dialog, sound effects, all the subtitles and the files for the blind/partially sighted, deaf and hard of hearing, and the security keys. In addition, the package has some extra files that tell the computers which of those files to play, and when. Continue reading “1) What Does It Mean: DCP”
The first question: Why Do We Care?
Every Answer begins the same way: There are many things that can go wrong with the presentation of the moving picture.
In this case, we are working with the shape of the picture. Movies evolved from almost square to very wide.
This topic is a little tricky. Even if the shape is wrong – too narrow or too short – at least the image is on the screen. In some cases, the images may look OK if you just glance at the image. But there are things to look for.
Will the audience care? Many will. They will think that the screen looks too small, or the image looks too small. (Nobody ever complains about too big!) They may complain that the people on screen are too thin, or too fat.
Buzzwords: “Scope” “Flat” “Format” “Constant Height” “Constant Width” “Aspect Ratio” “Two-Three-Five” “One-Eight-Five” (written 2.39 or 1.85 and 2.39:1 or 1.85:1). We will show the definition of these terms with examples. Don’t look them up now – they have too many meanings and most explanations are more complicated than we need to be.
The Complication: There are 2 correct forms for an image on the screen. Even in the same facility, some auditoriums may be one type, and other auditoriums may be the other type!
Potential Points of Failure: Screen. Curtains. Motors for Curtains. Cord for Curtains. Masking. Motors for masking. Chains for masking. Automation Electronics. Projector. Automation setting on Playlist. Instructions that tell which setting to put into the playlist!
Don’t let this get too complicated. We are only talking about the size of the rectangle of the movie on the screen.
Movies are created in 2 different shapes. The measurements for both of them is just about 2 times as large side to side (the width) compared to the dimension from top to bottom (the height). For example, the following picture shows this concept of a rectangle that is 2 times wide and 1 times high.
A simple way to write this is ‘2 to 1’ or ‘2:1’, which means 2 units in one direction compared to 1 unit in another direction.)
The important things to remember is:
There are two formats
One format is slightly smaller than 2 times wide and 1 times tall – that format is called Flat.
One format is slightly wider than 2 times wide and 1 times tall – that format is called Scope.
Here is a picture of those 2 formats placed with our 2 to 1 picture.
The choice for this happens very early in the movie making process – probably during the first hours of conversation between the producer and director, or sometimes the director and the cinematographer. Will we shoot this movie wide or do we shoot this movie tall?
Of course, they don’t use those terms. Art and Science are never that simple – there are always special words, or words with special meanings. They choose between “Scope” or “Flat”.
There is no rule that says a movie should be one way or the other. Sometimes a director will only work in one form, then suprise you by making a movie in another. Or, sometimes people will say that all action movies are in Scope. But a little research will show that isn’t always true.
Anyway, after the director’s decision, every scene of that movie will be shot through a lens that is in that form – what is called a format. And of course, the last lens of the movie process – the lens that is attached to your projector – will make the movie appear in that format on your screen.
Maybe you remember those old maps with the ship at the edge near the sign that says: Warning – Here Be Dragons~! Well…Warning — Here Be Maths~! …and, yes, we promised to keep math to a minimum. But there will be drawings too, with arrows and bright colors. So, be brave. Continue reading “10) What Does It Mean: Scope and Flat?”
There is no perfect answer for “Where should I be to judge the screen and sound system?”
Actually, we don’t need to be in a “perfect” place. We just need a consistent place – measure from the same place every time. Still…the question is: Where?
One group of experts will say that you should judge from so many “Screen Heights” away.
A screen height is just like it sounds, and a little difficult to evaluate exactly. In the movie theater, if a screen is 64 feet wide, then the height is 27 feet high. Maybe. Because there are two different standards for screens.
Continue reading “1a) Where to Judge The Auditorium”
Most of us here on the earth realm have two ears. There may be other realms with more, but with two we can do amazing things with sound.
Knowing the location of where a sound is coming from is one cool example. You can close your eyes and you can tell whether a sound is coming from the left or right or front center or anywhere in between. In fact, you can close your eyes and point with great accuracy to the location where a sound is coming from anywhere in the space around us, even behind, above and below. The science people call all this space, left and right, above and below, in front, behind – all this is called a ‘sound field’. Continue reading “Point 1, and Other Speaker Stuff”
We are preparing the launch of an exciting new service. Out with the old paper form of the Managers WalkThrough Report Form – In with the Online Forms. Give it a try.
Use the link on the line above, or click on the “Routines” pulldown in the Menu above. Select Managers WalkThrough Report Form on your phone or tablet or portable computer. Get settled in the auditorium that you want to check the sound and picture. When ready, have someone start up one of the Cinema Test Tools DCPs …and click away on the online form.
If everything is cool, all stays nice and simple. But if any of the answers requires that you pass information to the tech (for example), the form magically opens up, giving you a place to tell everyone what you saw or heard.
Like the DCPs and lessons, the new Online Form Series is free. We hope you will use it for every theater every week…or more if you want. The Safety and Security Form is just about ready and the Monday CleanUp will also be released soon. Read further to learn about emailing the form and other Q&A. Continue reading “Beta Test – New, Online, Managers WalkThrough Form”