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