PAINTING

CAMERAS

THE NEWSEST ART FORM

IN PHOTOGRAPHY

B y J a n n i c k P. R o l l a n d and S t e v e L . H y l e n

O p t i c a l a d a p t a t i o n s

o f c a m e r a l e n s e s

a n d t e c h n i q u e s h a v e

c h a n g e d a n d w i l l

continue to change

t h e o p p o r t u n i t i e s f o r

p h o t o g r a p h i c a r t i s t s

t o m a n i p u l a t e i m a g e s

m o r e c r e a t i v e l y .

Before the i n v e n t i o n o f p h o t o g r a p h y b y L o u i s

D a g u c r r e in 1839, people used s imple sketches,

d r a w i n g s , o r p a i n t i n g s to c a p t u r e i m p o r t a n t

i m a g e s . S u c h i m a g e s i n c l u d e d m o m e n t s i n

t ime , facial express ions, still lifes, the d y n a m i c s

o f p e o p l e in teract ing, a n d both the beauty and

harshness o f nature.

T h e process o f p h o t o g r a p h y that Daguer re invented

created a m a z i n g l y s h a r p p ic tu res that Were m a d e i n a

por tab le camera o b s c u r a , the s implest c a m e r a form that

artists had used for centur ies as a s k e t c h i n g - a i d , m o d i ­

fied to capture the p icture o n a l ight -sensi t ive plate. T h e

c o m b i n a t i o n o f p o o r lenses, o p e r a t i n g at s low f / n u m ­

bers, such as f /17 , a n d s low-ac t ing c h e m i c a l s , r e q u i r e d

e x p o s u r e s o f up to 20 m i n in b r igh t s u n l i g h t f o r a n

image to be r e c o r d e d . 1

Optics & Photonics News/July 1999 33

Figure 1. (left) A photograph of Isabelle t a k e n with a modif ied c a m e r a lens and convent iona l photographic f i lm. Figure 2. A photograph of C o q u e l i c o t s t a k e n with a modif ied c a m e r a lens and convent iona l photographic f i lm.

When Daguerre introduced his new process, the first lens to be used in a camera was the achromatic land­scape lens of Charles Louis Chevalier,1 an optician working in Paris. Improvements followed, many times based on important discoveries in optical design and improvements in photosensitive film. Perhaps the most important discovery in lens design was the establish­ment of the Petzval Sum, a measure of the curvature of the best focal surface for the image, that happened to coincide with Daguerre's role in 1839. Petzval's first lens, the design of which was based on his mathematical developments, admitted 16 times as much light as Daguerre's with a shutter speed of about f/3.6. It reduced the necessary exposure time to less than one minute, and was the photographers' standard for the next 60 years.

Camera functions continued to expand into the 1950s to serve multiple purposes across various fields of the arts and sciences. The market for cameras pushed photographic technology toward the capture of high-resolution, low-grain images in full color, for high-end photography and scientific discovery recording. The amateur camera market adopted a wide range of for­mats from high-end cameras such as Hasselblad to the popular single-use cameras such as those by Kodak found in any convenience store. Low-grain and high-resolution across a wide field of view, was the common denominator of these various technologies. It took years of dedication by many lens designers to achieve such perfection in high quality image capture.

While the discovery and development of photo­graphy for high-resolution, low-grain pictures belongs to the 20th century, the 21st century may lead the way to an entire new paradigm for photography as an art form. Certainly vivid images can be readily captured with today's photographic cameras. However, it is possible that the capability of cameras can be extended to cap­ture other dimensions that go beyond realism as a repli­

cation of the physical world. Today, realism is defined as the perfect, ideal replication. Anything else is subjective, such as impressionism, expressionism, or abstraction­ism. Artistic minds might prefer to define realism as the accuracy with which one captures underlying percep­tions and psychological meaning. The unanswered question is whether photography can provide a means to bring forth art forms in which cameras can be designed to capture images with the style and look of artists such as Claude Monet or Vincent Van Gogh.

Cameras that can capture images so that they resem­ble paintings are currently being developed. Artist pho­tographer Steve Hylen, one of the authors of this article, created the first painted-like images created with all-optical components. This process does not require any digital image processing. Examples of such pictures including Isabelle, Coquelicots, and The Boat are shown in Figures 1-3, respectively. A conventional-looking camera was used to take these pictures. When developed at the local store, they vividly mirror paintings!

In the Optical Diagnostic and Applications (ODA) Laboratory in the School of Optics and CREOL at the University of Central Florida, researchers are striving to model, design, and fabricate lenses for SmARTlens Inc.™ that will encode various artists' styles with all-optical devices. While they are also pursuing computer simulations to achieve such effects, their ultimate aim is to achieve these art form effects at the speed of light.

The primary issue is texture, a form of random pat­tern that is mathematically defined as an ergodic ran­dom process.2 In simpler words, each texture image could be a sample cut out of a larger fabric where each possible sample is point to point different from the oth­er ones, yet visually indistinguishable from each other no matter where in the fabric the samples are cut. This point is illustrated in Figure 4, where four different sam­ples of one texture were assembled in one larger image. In fact, one sample is a real image of a texture while the

34 Optics & Photonics News/July 1999

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three others were mathematically synthesized.3-5 The four images look so similar that the computer-generated images cannot be discerned from the real image, thus giving the impression of a unified texture.

Researchers in photography like to believe that real world images are mainly texture images, and that paint­ing is the art of reconstructing nature from brush strokes, a form of texture. With such a perception, paintings can be optically created by superimposition of texture forms.

The lenses described are being designed in the ODA Laboratory in collaboration with SmARTlens, Inc. to combine textures, part of which are the scene and part of which is the man-made texture of a brush stroke or some similar effect. The brush strokes are optically encoded as a transparent texture pattern on a plate, and positioned close to the film plane.6 Some defocus of the plate yields highest quality images, where quality is assessed by the artist's eye. Simulations of the imaging process through such photographic optics to predict the effect of optical texture capture for various system para­meters are being implemented.

Given the statistical properties of the texture patterns to be encoded, a couple of processes are under investiga­tion for the fabrication of the plates, and one of them is diffractive optics.7 A simple property of diffractive optics is the correlation length of the micropatterns making the texture that provides scale information about the texture. Interestingly, plates with specific sta­tistical signatures, such as Monet or Van Gogh, are being designed based on previous investigations of tissue characterization for medical imaging.4 Indeed, if the photographer wants to think of nature as being made essentially of textures or connected networks at multiple scales in multidimensional directions, the human tissues form 3D textures as well as nature does.

What is often most exciting about science is the study of fundamental sciences—such as texture characteriza­

tion—that apply from material science and medical imaging to the art form. This opportunity to use science as a vehicle for providing a new tool for artistic expres­sion has been particularly exciting for both the scientist and the artist. The fact that it will be possible to provide these developments to the amateur camera market makes it even more exciting.

Acknowledgments The authors thank the students of the ODA-Lab, specifi­cally Yann Argotti for creating the computer-simulation of the imaging system, Hua Hong for her assistance with the lens design of the cameras, Vesselin Shoualov for model­ing the scattering process of the plates, and Alexei Goon for his early contribution to the modeling of the imaging through such lenses. Special thanks is extended to Carolyn Abney for her editing skills and to Kevin Thompson for introducing us as partners for this art and science venture. This research is supported by SmARTlens, Inc.

References 1. R. Kingslake, A History of the Photographic Lens (Academ­

ic Press, San Diego, CA), 1989. 2. A. Goon and J.P. Rolland, "Texture classification based on

comparison of second-order statistics. I. Two-point proba­bility density function estimation and distance measure," J. Opt. Soc. Am. A. , 16(7) 1566-1574 (1999).

3. D.J. Heeger and J.R. Bergen, "Pyramid-based texture analy­sis /sythesis," Computer Graphics Proceeding, Siggraph, 1995, Los Angeles, CA.

4. J.P. Rolland et al., "Synthesis of textured complex back­grounds," Opt. Eng. 37(7), 2055-2063 1998.

5. J.P. Rolland and R. Strickland, "An approach to the synthe­sis of biological tissue," Opt. Exp. 1(13), 1997.

6. S.H.L. Hylen, "Image modifiers for use in photography," U.S. Patent No. 5,649,259, July 15, 1997.

7. D. Faklis and G.M. Morris, "Polychromatic diffractive lenses, " U.S. Patent No. 5,589,982, Issue Date: December 31, 1996.

Figure 3. (left) A photograph of The Boat taken with a modified camera lens and conventional photographic film. Figure 4. A composed image made of an original sample in the upper left quadrant, and three mathematically synthesized images in the

other three quadrants. The composed image appears as a unified texture as if photographed.

Jannick P. Rolland is assistant professor of optics at the School of Optics and CREOL (Center for Research and Education in Optics and Lasers) at the University of Central Florida, Orlando, FL. She also holds a Joint appointment in the School of Computer Sciences, University of Central Florida, Orlando, FL. Steve Hylen is an art photographer in New Milford, CT.

Optics & Photonics News/July 1999 35