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  • MCCANN: ...of fabulous pictures first time you ever held a camera. And then another,

  • and then another. I'm just making--make sure I'm not going to disappear here. Okay, we're

  • in the business. And that was the spot where I thought he might want to take a picture

  • and says, "No, I don’t see anything there." And I went back, took several more. And I

  • just felt like a complete clod. I felt I was, you know, walking through--going through a

  • garden, but I was stepping on all of the flowers. I just missed all the good photographs. His

  • visual command was just extraordinary. They--okay, that all seems to be working. When we look

  • at images in today's world, we usually think of Photoshop. We think of Photoshop as a sort

  • of a new thing because you can take any pixel and make into any other value that you like.

  • And you can characterize the scene by the histogram there. I guess I can see a little

  • bit clearer back there than you can here. And the total scale curve is probably the

  • most valuable feature that lets you transform the image you have into the image you want.

  • And so, here, we're talking about digits in and grayscale value out. But in fact, it's

  • a very similar curve to the original Hurter and Driffield, H&D curve that photographers

  • talked about and certainly are very familiar to the zone system. Okay, there we go. If

  • you compare film and digital photography, in fact, they're quite similar, although the

  • techniques are a little bit different. We have a lens, a camera, a sensor, sensor processing,

  • restore it, one case in a negative, another case in a digital file. We read it. We anticipate

  • what we want to do with the image and we display it. Now the tools in the optics are pretty

  • similar except the size constraints are a little bit different. It's the aperture of

  • the number of elements, the coding, the resolution, the volume of the camera, and the surface

  • of the sensor; it determines a lot of different things. And John had invited me two years

  • ago to discuss some work we've been doing in measuring how much information you can

  • capture in high dynamic range imaging. Today's popular technique is you take a series of

  • exposures and out of those many exposures, merge it into the image you'd like to have.

  • Now, in fact, if you look at the data very carefully, you find that all these nasty things

  • like number of elements, and codings, and apertures, and surface reflection; namely:

  • glare. Glare provides a serious limit to what you can capture on the film play. The multiple

  • exposures you take do not give you information about the scene. They give you information

  • about the scene plus the veiling glare, the unwanted stuff that happens in the camera.

  • And so, it turns out what you have on that image plane is a function of not only the

  • scene but the features of the camera. So, HDR imaging is not an accurate rendition of

  • the scene but it provides more useful information. Although it just doesn’t happen to be the

  • real accurate information. So you take--and that’s the same for both whether you're

  • on a digital camera or a film camera. The techniques--and so the highlight or you put

  • it in the--you go into the dark room, you put it in a developer, you stop the development

  • with acidic path, you put it in hypo to get rid of undeveloped silver, you wash it, you

  • tone it to change the--I see you change the surface properties of the silver to get a

  • better covering power, and then you wash it again, and you dry it, and you have a finished

  • negative. In digital imaging, you have an A-to-D converter. You have something that

  • does noise reduction. You transfer that signal to a digital part of the system where you

  • do the de-mosaic-ining, the sharpening, the image enhancement, and then you compress it.

  • Now on the printing side, you can use different types of enlargers which in fact affect the

  • essentials of response function, and the grades and the surface and the whatever. So, what

  • I hope to do in this talk is to compare this, probably, for most people your age, unfamiliar

  • things, because you probably haven't spent much time in the dark room, with a wonderful

  • techniques we use in digital imaging. And just, by the way, Ansel was my coach in black and white chemical photography and John

  • Franklin here was my coach in digital photography. At 19--what was it, '72, you started to set

  • up a digital image processing lab at Polaroid which was far ahead of most other labs that

  • started to do image processing for photography. Ansel divided making a print into three very

  • important steps. First of all was the visualization. For Ansel, you had to have an idea of what

  • the picture was supposed to do before you took the picture. It wasn’t the occasional,

  • "Let's grab something and then refine it later." It was--the negative should be very carefully

  • composed, exposed, and developed. In fact, Ansel went to the trouble of changing the

  • characteristic--anticipating what the film should do and exposing with the type of development

  • he was going to do in mind. And I'll talk about that more later, but you wanted to visualize

  • for what it was. The second step was to capture all the usable information and he often described

  • that as the musical score. He was at his young man, he was trained as a concert pianist and

  • he was both a photographer and a pianist, and he found it difficult to spend the time

  • for doing both and he decided to become a photographer. It's quite common to think of

  • a pianist to spend hours per day just practicing. Ansel took that framework and did it with

  • his photography. He practiced taking pictures more than anybody I ever met. Most of us grab

  • the camera, go take the picture. Well, Ansel would never do that. He would take the camera.

  • He would try this setting, that setting. He would continually learn how to do these things.

  • And he was an absolute master of capturing the musical score. And in fact, what he was

  • doing, we would say today--we would say, well, he was controlling the tone scale of a sensor.

  • Then he would render, you'd call that the performance. And there's two parts of that.

  • First, is you want to scale, you want to get the best tone scale, a response from the media

  • you're going to, the printer or the display, or whatever. But also, in many cases, because

  • the dynamic range of the print is very limited, he manipulated using a kind of spatial processing.

  • This was essentially dodging and burning, moving his hands around to make an image that

  • fit his visualization. And that's really the essence of the talk. Now, in fact, just yesterday,

  • there was a symposium at the electronic imaging meeting in San Jose. The keynote speaker there

  • was John Sexton, longtime friend, colleague, co-worker of Ansel's. And I just wanted to

  • let you know to put on your calendar; John's going to be speaking in the Adobe Distinguished

  • Lecture Series. I think it's going to be June 15th. But--you'll find it on the Adobe website.

  • And he just gave an absolutely marvelous keynote address where he talked about Ansel's images,

  • how Ansel made the images, how do old movies of Ansel climbing to, actually climbing to

  • take these pictures here, and with music accompaniment by Ansel playing the piano. So if you're an

  • Ansel Adam's fan, look up John Sexton on Adobe Distinguished visual. He's coming to an auditorium

  • near you soon. Ansel regarded this picture taken in 1927, that’s in Yosemite Valley.

  • He and his wife and three friends climbed halfway up. He climbed up to this, they call

  • a diving board. It's about halfway up to the top of--they brought up picnics, they were

  • all photographers. They took pictures. Virginia, his fiancée, later his wife, the lifelong

  • wife, was--went with him and took movies and you'll see him in John's talk. Ansel took

  • these pictures with a 6x8 view camera. He brought up glass negatives. And the reason

  • they were glass was that, essentially this was even before you could get panchromatic

  • emulsions on nitrate-base. There wasn’t a safety film base that we used today. This

  • was only old very unstable nitrate base material that they used in that time, but you couldn’t

  • even get that. There had to be a glass plate if you wanted panchromatic emulsions, which

  • means sensitive to red light. Ansel took the picture on the left with a yellow filter and

  • then he visualized. You see--he didn’t--there were no digital displays to see the image

  • that you just took. He started to think in his mind what's that going to look like? "Well,

  • I'm going to have a gray sky and it's going to be next to a gray monolith." And he had

  • such familiarity with his tools that he said, "Oh, I'm not going to like that picture."

  • But the sky is going to distract from the impact of the half dome of the monolith. So,

  • he then--in those days, he reported to John there were no accurate light meters so it

  • was his photographic experience that told him how to expose the negative. And he had

  • practiced enough so he knew that with a dark red filter you needed two and a half stops

  • more exposure. So he adjusted the exposure, took the picture with a red filter which rendered

  • a black sky which left the vision of--his vision of the monolith become apparent. And

  • he often told me that he was so excited when he took that picture. He ran down the hill.

  • You'll see it in the movies. It's a 45 degree climb. And he immediately went to the dark

  • room and made the print and it was--he'd often described that it changed his life because

  • he now knew that he could manipulate things to do the things we all know we can do in

  • Photoshop. An HDR or my favorite paper is a paper by Jones and Condit from Kodak. It’s

  • a paper that measures a great number of scenes, 126 outdoor scenes, and measures the dynamic

  • range. And this is mainly to illustrate that the world that have a 3.0 log unit range,

  • most of the scenes that they took that they thought would be average people pictures would

  • be 2.2 log units. But in the print you have right around a hundred to one. You don’t

  • have--you have a natural smaller range in the print than you do in the worlds. So how

  • do you take this great big world, this wide dynamic range of stimuli, and put it in a

  • low range media. In fact, this is what the color negative film. If you think in the last

  • half of the previous centuries, there are probably a trillion prints made from a Kodak

  • negatives or Fuji negatives or--and essentially, that is a technique where it compresses the

  • highlights and the shadows and it in fact expands the midtones. If you take an Ansel

  • Adams print, make sure you're not measuring any glare from the glass or the surface of

  • the print. You get a 0.15 candelas per meter squared from the rich black sky and from the

  • white bright clouds, you get 17. That’s a ratio of 114 to 1 is the range of the print

  • can deliver. Now these blacks and these whites are amongst whitest and blackest you will

  • find in photographs. They are very skillfully done. They're selenium tones so that the densities

  • here are deeper than most materials, and Ansel was a great craftsman so that there was always

  • minimum density in the whites. So how do you fit this into the world? Well, what you do

  • is you can't do what we say a CCD does. A CCD counts for tones and you have a nice simple

  • linear relationship that run the amount of light caught and the value coming out. The

  • fellow who was a director of research at Kodak for 50 years, a guy by the name of Mees; and

  • in fact Mees was one of the few--I worked a lot with, Edwin Land for--at Polaroid. And

  • there are some people you always knew he had a great respect for. He would just almost

  • change his tone of voice. And he would always refer to, just to me, as just the great director

  • of research at Kodak, because essentially, he started off at the University College London.

  • He repeated Hurter and Driffield's experiments. And namely, he measured the sense of trimetric

  • response of films. He invented the tone scale in his book in 1920. He described, here, you

  • have two tones, and here you have three tones when you add a shadow and four tones if you

  • add that fade shadow. And so he was describing the response of a film as a tone scale. Now

  • that fit very well with the--Kodak sort of had a policy. And around 1900, they introduced

  • the Brownie camera and the idea was, "We'll, you take the picture, we'll do the rest."

  • And it was quite an organized and big thing because in fact, there was a newspaper ad

  • in just about every paper in the United States all at the same time by 1901 or 1900 or something

  • like that. So that was a pretty big organization. No Google ad where you could do it at one

  • email. You have to write all those letters to get that many people to do it. Well, Kodak

  • had a policy that they really wanted to get away from the complex jargon and all the secret

  • formulas of a previous century of photography. And so they wouldn’t let him talk about

  • H&D curves. He had invented a new synonym for sensitivity response function and that’s

  • tone scale. And tone scale is something we use, continue to use today. Here is Ansel

  • Adams' zones which are very similar. And you can see the--he tells you that this white

  • reflected roof is zone nine. And this was the middle gray, zone five. And this is a

  • black, zone one. So each of these were characterized, they're one stop apart. And as soon as he

  • could use spot pathometers, he measured these areas so he could determine the range of the

  • scene. And if he knew the range of the scene, he knew whether he should plan to compress

  • in the development or expand in the development. To do that is relatively simple. Here's a

  • set of zones with normal development for that negative. If you decrease the amount of development,

  • you'd essentially lower the contrast, you'd lower the slope of the curve, you'd get to

  • a wider range response. You'd get a still lighter range response if you decrease it

  • even more. Oppositely, if you extended the time on the developer and if you have a sharp

  • dynamic range scene and you wanted to make that punchier, you would increase the development

  • time. The jargon I learned before meeting Ansel was always, you know, "overexpose and

  • under-development." And Ansel will always say, "No, that isn't right. You're going to

  • increase or decrease. You know what you're doing so, it's not over or under, you know

  • what you're doing." Today, we just think of it as, well, more development gives you a

  • tone scale curve that looks like this, less development gives you like this but you could

  • do this in a digital sense. You could set the quantization of the camera before you

  • take the picture to optimize it for the scene. But that doesn’t fit the current attitude

  • towards photography. Nobody in fact would even think of that. But it's quite a remarkable

  • thing to be so careful and thoughtful about what you're doing. This is kind of interesting

  • because if you take a simple linear representation of amount of light between a 100 and 0 and

  • put it into equal steps, you got a grayscale or a zone scale or a tone scale that isn't

  • very well spaced. You overemphasized the whites if you have a linear display of the range

  • of information available. And that’s why photographers always used log because that

  • gives you a better representation. It means the middle gray is not 50 percent reflectance;

  • it's 18 percent reflectance. And in fact more recently, people have started to use lightness

  • which is a cube root function instead of a logarithmic function. It better accommodates

  • the fact that you get scatter in your eye and so these are equal steps in appearance

  • if you use the cube root. So, these are all now logarithmic representation or rather these

  • are exponential and that these are each factor of two more light than the other along the

  • horizontal axis. These are optical density. So that’s log luminance, or log light, transmitted

  • through the negative. So this is the effective development. That means two times the normal

  • time in the development, or one unit, there wasn't [INDISTINCT] two times, but more or

  • less development. These are the similar kind of responses you get from changing the grade

  • of the paper. Now, these--all these graphs, in fact, were made by John Sexton in the second

  • edition of a set of books that Ansel wrote. And I'll show you the titles and references

  • at the end of the talk. They're still available today. They're fantastic books. But these

  • are all just taken from Ansel's book, The Negative. So, let me just go through it. Here's

  • the paper grade. The manufactures would sell you different contrast papers so that you

  • could make your negative look more contrast to you or less contrast to you. And as you

  • can see as you increase the rate of change you would decrease the range. So those are

  • two are always linked together. Just about now, everybody uses a spectral film so you'd

  • use a slightly different colored filter on the same piece of paper and that would change

  • the slope just like changing the paper. In the old days, you had to stock three or four

  • different kinds of paper to make the print. This is again the Ansel's example. If this

  • is the range of the negative and the positive print on grade one would give you this long

  • low slope low contrast image. But on grade three, you would take and make that higher

  • than the normal print. If you change your brand of developer or your concentration of

  • the level, you'd similarly get a curve like that. The emergence time factor is also an

  • interesting thing. You're working with a chemical that reacts and so that it is consumed. So

  • if you're making 20 prints, the 20th print will be lower in contrast than the first print

  • because your concentration of active ingredients has decreased substantially. It's been used

  • up by the previous 19 prints. So Ansel had a very ingenious system. When you're sitting

  • in a dark room you have a safe line. That would be a far red light or a yellow light.

  • And you can see the print, you can't see it well, but you can see the print. So he would

  • time, the length of time from when he put it in the tray to when he saw a particular

  • object emerge. And so that might be 10 seconds in the first processing. And then he had a

  • factor figure. If it was factor 10 that means I will take it out of a 100 seconds. And so,

  • if--now, in the next print, it might take 11 seconds, well, you take it out on 110 seconds.

  • So, he multiplied the time of emergence by the factor. And so by doing that, you can

  • see here over here, he has plotted diluted negative, the diluted developer solution.

  • Using this technique can overcome the effect of the diluted development. He can get a constant

  • result out from a chemical bath that was changing uncontrollably. We've already talked about

  • development time. And the enlarger, it depends upon whether you've got collimated light or

  • diffused light. And the selenium toning is a very interesting thing. If you process the

  • developed silver with these selenium salts, it actually changes the surface property of

  • the silver and gives you a blacker black. And Ansel was an absolute master of that.

  • You can also go wrong if you would put the right--you can get the black silver to change

  • color if you file that up. Well, what's beyond the tone scale? This is important but what

  • I think makes Ansel's work spectacular is the things he did beyond the tone scale, the

  • dodging and burning. The best example of that is an experiment that happened a little bit

  • before John joined our lab. It was an experiment by Edwin Land called the black and white Mondrian;

  • because in this experiment, he had a bright light near a dark gray object and the illumination