JAIC 2001, Volume 40, Number 3, Article 5 (pp. 233 to 258)
JAIC online
Journal of the American Institute for Conservation
JAIC 2001, Volume 40, Number 3, Article 5 (pp. 233 to 258)




1. Elements are the discrete visual or audio components in a work, such as slide, video, and Web components.

2. Channels refer to electrical signals in an artwork— video signals, or feeds, or audio signals sent to the speakers.

3. Installation art was not made in multiples prior to the late 1980s (approximately 1987). Artists typically made one-of-a-kind works, and a work was sold only once. The artist could not show the work after it had been sold without the permission of the owner. In the case of Pornography in the Classroom, Acconci, not his gallery, holds the masters; another edition will not be made from them.




Quoted from Kramlich Collection (2000) registration materials assembled by the Thea Westreich Art Advisory Services:

Monitor image:

  • VHS tape, NTSC format with sound, total 60 minutes.
  • The piece is comprised of a sequence of 29 spoken phrases (parallel to the appearing and vanishing image). Two phrases are repeated in irregular intervals.
  • Running time: 21 minutes, 58 seconds (Betacam SP) on the VHS tape, it is 21/2 times looped.

Projected images:

  • VHS tape, NTSC format, no sound, total 61 minutes, 38 seconds.
  • The piece is comprised of a sequence of 66 different views (camera moving over photographs of female bodies).
  • Running time: 35 minutes, 28 seconds (Betacam SP) on the VHS tape, it is 12/3 times looped.

Pornography in the Classroom, 1975 (VAT79), includes:

  • 1 Kodak Ektagraphic slide projector with a variable timer
  • 80 35 mm slides in carousel (slides are labeled and numbered)
  • 2 VHS video tapes (one for monitor, one for wall projection)
  • Installation diagram from Vito Acconci certificate issued by Barbara Gladstone Gallery

Equipment needed:

  • 1 video projector with ceiling mount
  • 1 monitor
  • Various cables required for setup
  • 2 auto-repeat VCR players



Seeing Time catalog entry for Vito Acconci, Pornography in the Classroom(Riley et al. 1999, 144–45).

During the 1960s and early 1970s American art was transformed by a climate of radical experimentation, influenced by new psychological and social theories, sexual liberation, and political rebellion. Vito Acconci was a pivotal figure in a group of artists whose work in performance, body art, video, sound, and installation during this period redefined the parameters of art.

Pornography in the Classroom belongs to a group of installations Acconci made in the mid-1970s, after he stopped working with performance. Its title refers both to the grounding of Acconci's work in writing, literature, and language and to his subversive use of sexual content to destabilize the viewer and disrupt the repressive social order, for which the classroom functions as a metaphor. Acconci's mutation of the classroom into the gallery—which, for him, operated as a “general structure,” “training room,” or “frame-work for meaning”—suggests the construction of an alternative social structure.

Fig. A-1. Vito Acconci Studio drawing showing basic installation of Pornography in the Classroom (not to scale)

Language, in spoken and written form, is inserted into the gallery “framework” as a parody of the ordering system. Eighty slides are projected into one corner of the darkened gallery, showing a blackboard on which titles of books appear one after the other, in alphabetical order, written in white chalk capital letters. The books cover topics that were of deep importance to Acconci's thinking and to the counter cultural climate of the 1970s: psychology and social science (Transcultural Psychiatry, Sociology as a Skin Trade, Identification and Projection), philosophy (The Dialectical Imagination, The Negativity of Reality), radical politics (A Manual for Direct Action, Society Against the State), and linguistics (Language as a Symbolic Action, The Sociology of Mass Communication). These titles represent a body of thinking about the redefinition of the self and society. Their collective presence, a kind of alternative syllabus for the classroom, reflects Acconci's deep interest in semiotics and the role of language in the production of meaning.

Inserted after every nine titles are single words in red, expressing strong emotions—fear, desire, frustration, envy, anger, hate, detachment, will—all indirect subjects of many of the book titles. Projected in the opposite corner of the room are large color close-up images of naked women's bodies, resembling stills from a pornographic movie, which are arguably the focus of the conflicted emotions expressed in red on the opposite wall. In front of the projected images, a small monitor on the floor displays an erect penis in black-and-white, which appears every thirty seconds, rising vertically toward the image, as Acconci's voice shouts,“Help me, I'm drowning. Land ho!”

The conflicted emotions expressed by the words in red, the comical presentation of the small male organ encountering the large erotic image, and the ambiguous fear and pleasure in Acconci's sensation of drowning in the erotic, maternal body, all suggest a sense of emotional and sexual confusion and inadequacy before the female. Acconci's relationships with women, and his often-disturbing feelings about intimate emotional and sexual issues, became subject matter for his work. The projection of his inner anxieties outward became a strategy for defining the self, using the personal for impersonal ends. The juxtaposition of sexual space with a space of learning also suggests a blurring of the boundary between public and private (domestic, intimate, erotic) space, a theme that many artists explored during this period.(Acconci's provocative performance Seedbed [1972] became a land-mark of this genre.) The late 1960s saw a reform of censorship laws, which brought pornographic film into the open for the first time. Acconci's reference to pornography reflects both the importance of sexual freedom in 1970s counter-culture and his interest in the increasing power of the media, of which pornography was rapidly becoming a part, in shaping American identity.

On a more abstract level, the symmetry of the piece underlines Acconci's analogy between the body and a word system. The spatial split between the body and language reflects the underlying semiotic nature of much body art. The gallery space was regarded as a perceptual field, onto which, as Kate Linker has observed, the human subject was mapped in space and time! Within this structure Acconci reveals the self to be fragmented, split, divided. Pornography in the Classroom epitomizes the profound transition in American culture that took place in the 1960s and early 1970s, from the coherent unity of the heroic modernist “I” to the decentered, fragmented, postmodern self.

Fig. C-1. Installation drawing of the floor plan for the full room of James Coleman's INITIALS. Drawing by Coleman Studio



Quoted from Kramlich Collection (2000) registration materials assembled by the Thea Westreich Art Advisory Services. The following written documentation was supplied by the James Coleman Studio. A random section was removed at the request of the studio so as not to publish the complete text of the artwork's documentation.


  • Units x 3 Kodak Ektagraphic III E (manual focus) or Kodak 2050 carousel projectors
  • Units x 3 Schneider Vario-Cinelux 85– 210mm f3.9 zoom lenses
  • Units x 3 Kodak covered slide trays (80 slides each)
  • Units x 1 Buhl stacker-stand for Ektagraphic III—3 tier; no. 577–33 (or for Kodak 2050 projectors as required)
  • Units x 1 AVL Dove X2 (no alternative possible)
  • Units x 1 Tascam CD 301 player unit, or equivalent CD player
  • Units x 1 amplifier (stereo) with stereo equalizer system
  • Units x 1 stereo equalizer unit
  • Units x 4 high-quality speakers (excluding optional fifth speaker)

Fig. C-2. Installation drawing detailing various elevations of Coleman's INITIALS. Drawing by Coleman Studio.

Fig. C-3. Installation drawing showing pedestal design for Coleman's INITIALS. Drawing by Coleman Studio

Also required: Cables for equipment installation relative to equipment deployment to include an AC power bar with surge protector

Projectors are placed on a Plexiglas pedestal specifically designed for installation and exhibition space (see appendix A architectural drawings).



The work is installed in a space (blackout) specified in the drawings to accompany these notes. Installation of the equipment and the alignment of the projectors is carried out by an experienced, professional AV technician. Due to the fragility of the slides and software, only experienced technicians must install the work.

Consult the architectural room plan, which includes detailed technical instructions for installation.

Under no circumstances should slide material be brought into the space before the technical installation is completed.

1.2.2 PRIOR TO INSTALLATION Equipment Check

Check that:

  • equipment is fully functional
  • Tascam CD-301 is equipped with remote control, which controls the repeat function. The CD player must have a repeat mode
  • sufficient replacement projector lightbulbs are available
  • sufficient fuses for all equipment are available
  • equipment is provided with the correct cable connections
  • connecting cables from Dove X2 to projectors have correct connectors/adapters
  • all equipment functions correctly from CD program using CD and empty carousel slide-trays Room Check

Note: Check that there are no light leaks through cracks or openings in the ceiling or walls. Check that all construction and preparatory work in exhibition space is complete, i.e., (1) cable-laying, (2) loud-speaker installation, (3) acoustic insulation, (4) carpet-laying, (5) painting. Check that space is thoroughly vacuum-cleaned after construction work is completed.

Fig. C-4. Specifications for Coleman's INITIALS. Drawing by Coleman Studio

Note: After vacuum cleaning, a minimum time of six hours has to be allowed for dust to settle before the installation of slide projectors and equipment may begin.


[The text from the following sections was omitted at Coleman Studio's request.]

  • Projector/AVL X2 Installation
  • Acoustic Installation
  • Commencement of Projection
  • Slide Maintenance

Condensation: The exhibition space should be kept at a constant temperature of not less than approx. 20� Celsius to avoid condensation during projection. Condensation can be very damaging to the images.

Dust: Dust levels must be kept to a minimum in the exhibition space. The images must be periodically checked for dust and dirt.

When slides have to be cleaned, this work must be undertaken only by a professional slide-lab technician. The laboratory will be equipped with the adequate facilities, i.e., anti-static air and brush-cleaning.

All images are mounted in WESS mounts, a number of spare mounts are included. It is important that the technician carefully removes one slide only at a time of cleaning and replaces it in the cleaned WESS mount prior to opening a second image. This is necessary to avoid any risk of slides being replaced in incorrect mounts.

After cleaning the slide and slide mount, the technician must be careful not to reverse the slide.

All slides are coded and must be replaced in the exact slide with tray number. Any mistake will destroy the sequence of images to audio-synchronization and the integrity of the presentation of the work.

After extended projection hours, the color of images will depreciate and eventually fade. At this point the entire set of images (trays A, B, and C) must be replaced. It is not possible to replace only the faded images.

New complete copies and duplicates of the work may be acquired through Art Productions. Please allow six months for reproduction when you order. Please quote the confidential ordering number supplied in the acquisition contract.



Copyright � 1995 Gordon Rudd at www.cloversystems.com/verisnot.htm

1.1 Cross Interleave Reed-Solomon Code (Rudd 1995)

All CDs incorporate an error detection and correction scheme known as Cross Interleave Reed-Solomon Code (CIRC). It would be impossible to make a usable CD without this error correction, since many errors are generated playing even the best discs under ideal conditions. CIRC is a powerful error detection code that can detect and completely correct all errors on a reasonably good disc. It relies on two principles for its operation. One is redun-dancy. Extra parity bits are added to the data stream to facilitate error detection and correction. These extra bits reduce the available capacity of the CD by about 25%.

The other principle is interleaving. The data is not recorded on the disc in its natural order as it would be on tape or magnetic disk. The data are organized into blocks of 24 bytes (called “symbols” in CIRC terminology). These are the blocks referred to in the Block Error Rule measure. Four parity bytes are added to each block of 24 symbols (bytes), making the block 32 bytes long. The data symbols belonging to one block are then distributed over a fairly large area of the disc by “interleaving” them with symbols from other data blocks. The 24 symbols of one data block end up distributed over 109 data blocks. The advantage of this technique is that physical defects on the disc do not eliminate complete data blocks, but instead, parts of many blocks. These partially bad blocks can then be reconstructed using the parity information.

CIRC error correction is done in two stages referred to as C1 and C2, with deinterleaving of the data taking place between the stages. The C1 stage is used to recover from random errors caused by noise in the signal; the C2 stage is used to recover from larger errors caused by physical defects such as scratches and dirt. The error correction chip typically can correct two bad symbols per block in the first stage, and two bad symbols per block in the second stage. Some chips can correct four bad symbols in the second stage.

1.2 Layered Error Detection Code and Error Correction Code

CD-ROMs include an extra layer of error detection and correction, usually called Layered Error Detection Code and Error Correction Code (for brevity's sake, typically referred to as Layered ECC), that works similarly to CIRC by adding parity information to each data block. The extra error correction capability can correct errors that are not correctable by the CIRC because it adds additional parity bytes and additional scrambling of the data.



There are two basic methods of measuring film color, densitometry and colorimetry (see below). The traditional method for measuring film is densitometry, a photographic technology developed in the era of black-and-white film and prints. Densitometry is more sensitive to changes in darks than in lights. It is not as sensitive as the human eye (Popson 1989).

When densitometry is applied to color, filters are incrementally placed over the light sources, and the three resulting values are run through an equation to yield the single number measurement. Another method is to measure a specific color patch using a gray scale—that is, measuring just the lightness or darkness of the patch, not the color. A single number is reported for a specific color patch, based on the original density. Shift in color tint would not be noted using this method.

Density (D) has a logarithmic scale. A density of 2.0 is 10 times as dark as 1.0; a density of 3.0 is 100 times darker than 1.0. Few materials have a density greater than 4.0. Color transparencies generally have a density range of 0.05 to 1.0–1.6. The author's Kodak Q60 (IT8.7/1) 1999:03 transparency color target has a density range of 0.11 to 1.40. The thinnest colors are at about 0.15D.

In practice, a density measurement would be made before exposure to light (T1) and then measured again after exposure (T2). If the difference (T1 – T2 = ∂1–2) is less than 0.3 of T1(30% of the original measurement), then the change would not be great enough for the slide set to be pulled from exhibition. If a medium green has a density of 0.9800, then a light green has a density of 0.1679. A 30% change in a 0.1679D green is 0.05D units (0.1179D). The thinnest density the author has ever measured was 0.04; 30% of this value is 0.012D, which is right on the theoretical limit of the density measurement.

The measurement in a thinly colored area could easily fall below the native repeatability of the density measurement, which is 0.01 (Popson 1989). The precision of any actual instrument is often less than theoretical limits of the measurement, so a measurement could be so small as to fall below the abilities of a specific instrument; that is, a significant change could be present, but it could not be measured by the densitometer. Examples in Coleman's work would be thin colors such as light blue background or a delicate yellow tint in a cream-colored item of clothing.

The percentage of density change is calculated from the beginning measurement for the color being evaluated. If the color to be measured has just a slight tint (0.15–0.25D), a 30% change will be a relatively small amount. If the color has a medium density (0.6–1), the change will be much larger, and small changes (10–20%) will be instrumentally perceptible.

Densitometry is not ideal for measuring differences in color, although it is the traditional tool for measuring photographic materials.


Colorimetry is a method of measuring color with three-value (tristimulus) color spaces using basic XYZ color coordinates. It is the standard for the measurement of color. Colorimetry data is commonly output in several alternate color spaces, with L*a*b* (Lab star) the most dominant at this time in digital imaging.

Delta E (δE) is a method of determining change in two colorimetric measurements. The δE equation for the L*a*b* color space is: δE = [(δL*2) + (δa*2)

+ (δb*2)]1/2, where δL* = δL*x –δL*y, and where x >and y are taken from the same site at different times.

It is generally advisable to make at least three (if not nine) measurements and average them before making the δE calculations.

The units of color change in colorimetric measurements, δE, are of equal value across the scale. The best human perception is 1δE for trained observers, and 3–5 δE for the average person. The theoretical limit of detection is 0.05. In practice, good instruments have a precision of about 0.1, thus 0.1δE is the commonly accepted measurement precision. Colorimetry is 13–20 times more sensitive than the human eye (Popson 1989). A change of 20δE is quite large.

Coleman's estimate of 30% difference could be calculated as follows: the L* axis has a value of 0–100, while a* and b* have values from –60 to +60, or 120 units, from one pole to another. The maximum δE is therefore 197. A 30% difference of the absolute maximum (197) is 59.1 δE units. This is a very large difference. Clearly, a 30% δE is not an effective analog to the density measurement, because red and yellow are about 30% different in δE in the L*a*b* color space. If colorimetry is going to be used, the degree of “difference” permissible should be several times the perceptual ability of the average human, about 10 δE in critical situations and 20 δE units for normal applications.

Colorimetry is more sensitive to color change than the human eye, and it is especially critical for measuring slight changes in small amounts of color (where fading occurs first) (Popson 1989). Hand-held devices for measuring reflective color have become very inexpensive. In mid-2001, however, there are no “inexpensive” methods of making transmission colorimetric measurements. Measurement of film requires an integrated light source; these devices are still expensive. The Gretag-Macbeth SpectroScan T comes in a hand-held version with an integrated light source for transmission measurement of film. Bench-top units are more expensive.


The author extends a special thanks to Christopher Eamon, curator of the Kramlich Collection, for editing this text. Eamon also helped resolve the issues associated with Vito Acconci's artworks. Colin Grif-fiths helped resolve issues with James Coleman's work. A. J. Coleman, son of James Coleman, spent several hours of phone conversations helping to get the details correct, to the best of my abilities. The author wishes to thank the Coleman Studio for allowing the publication of Coleman's technical drawings and text. Both Steve Dye and Matt Bieder-man, technical installers at SFMOMA, were very forthcoming with their knowledge. Special thanks to Robert Riley and Jeffrey Walkowiak of Thea Westre-ich Art Advisory Services.

The two excellent artworks in this “TechArchae-ological” analysis reflect the fine efforts of the artists, their galleries, the agents of the Kramlich Collection, SFMOMA's installation, curatorial, and conservation staff, and Mona Jimenez and Paul Messier, who organized the TechArchaeology Symposium in 1999–2000.

The author has made a good-faith effort to get accurate technical information, but it is only as good as the era in which it was gathered. Technological eras are becoming shorter, and in the near future (one to four years), these technical projections will need to be reconsidered based on newer technology


Acconci, V.2001. Personal communication. Acconci lecturing at CCAC, San Francisco, Calif.

Coleman, A. J.2001. Personal communication. Spokesman for James Coleman, Marian Goodman Gallery, 24 W. 57th St., New York, NY 10019.

Cooke, L.1995. Introduction to James Coleman: Projected images, 1972–1994.New York: Dia Center for the Arts. www.diacenter.org/exhibs/coleman/coleman.html (accessed October 2000).

Dye, S.2000. Personal communication. New media installer, SFMOMA, 151 Third St., San Francisco, Calif. 94103.

Kramlich Collection. 2000. Personal communication. Information provided by Thea Westreich/Art Advisory Service, 114 Greene St., New York, NY 10012.

Krauss, R.1997. … And then turn away? James Coleman.Vienna: Wiener Secession; Brussels: Yves Gavaert.

Laurenson, P.2001. Personal communication. Tate, Millbank, London SW1P4RG.

Popson, S. J.1989. A comparison of densitometers and colorimeters. TAPPI Journal2(3):119–21.

Real, W.2001. TechArchaeology: Toward guidelines for practice in the preservation and documentation of installation art. Journal of the American Institute for Conservation40:211–31.

Riley, R. R., M.Sturken, and C.Iles. 1999. Seeing Time: Selections from the Pamela and Richard Kramlich Collection of Media Art.San Francisco: San Francisco Museum of Modern Art.

Rudd, G.1995. Why data verification is not enough! www.cloversystems.com/verisnot.htm (accessed 1995); also available from www.archive.com.

Sterrett, J.2000. Personal communication. Director of conservation, SFMOMA, 151 Third St., San Franciso, Calif. 94103.

Tuer, D.1996. Blindness and insight: The act of interrogating vision in the work of James Coleman. In Robert Lehman Lectures on Contemporary Art, no. 1, ed. L.Cooke and K.Kelly. New York: Dia Center for the Arts.

Wilhelm, H., and C.Brower. 1993. The permanence and care of color photographs: Traditional and digital color prints, color negatives, slides and motion pictures. Grinnell, Iowa: Preservation Publishing.

Zippay, L.1991. Electronic arts intermix: Video. New York: Electronic Art Intermix.


TIMOTHY VITALE is a conservator and consultant with more than 30 years' experience in treatment, survey, research, imaging, management, and consulting. Institutional venues where he has worked include Winterthur Museum, Museum of Fine Arts, Boston, Pierpont Morgan Library, National Archives, Smithsonian Institution, and Glasgow School of Art. Now in private practice, Preservation Associates, he works out of his Emeryville, California, imaging studio and the Oakland Museum Conservation Center's paper conservation laboratory in Oakland, California. He has a bachelor's degree in art history and chemistry from California State University at San Jose (1974) and a master of science degree in art conservation from the University of Delaware (1977). Address: 1500 Park Avenue, #132, Emeryville, Calif. 94608.

Copyright 2001 American Institution for Conservation of Historic & Artistic Works