All 4 books by Edward Tufte now in
paperback editions, $100 for all 4
Visual Display of Quantitative Information
Beautiful EvidencePaper/printing = original clothbound books.
Only available through ET's Graphics Press:
catalog + shopping cart
All 4 clothbound books, autographed by the author $150
catalog + shopping cart
Edward Tufte e-books
Immediate download to any computer:
Visual and Statistical Thinking $2
The Cognitive Style of Powerpoint $2
Seeing Around + Feynman Diagrams $2
Data Analysis for Politics and Policy $2catalog + shopping cart
Edward Tufte one-day course,
Presenting Data and Information
San Francisco CA, December 3, 4, 5
San Jose CA, December 7
I have just received, through an e-mail discussion list for archeologists, news that Kodak will discontinue production of the Carousel projector in 2004. Although the notice I received did not say so, it seems likely that the use of digital projectors and Powerpoint, especially in business and industry, is to blame for this.
The notice I recieved contained this:
"Slide projectors continue to be used in many government applications due to a proven track record of cost-effective, reliable, high-quality image projection. Combining the seven years of service and support with a long history of trouble-free operation, means that slide projectors will continue to enjoy many years of productive use."
Now, too much can be made of this. Surely there are tens of thousands of serviceable Carousels at work today, and they won't be soon junked, especially as long as the weakest digital projector retails for five times the price of a Carousel.
For many years, dual Carousels and twin projection screens have been a hallmark of sessions at the Geological Society of America. I have not been to a meeting for five years; it is possible, even likely, that digital projection is replacing analogue images there.
One has to wonder whether physicists and mathematicians would ever give up their beloved overhead projectors for digital technology.
-- Mark Hineline (email)
I am adjunct instructional media professor at Boston University. I have been using dual slide projectors for years. Image resolution is exceptional and the greatest advantage is image size for visual comparisons. This analog projection system has been very effective for my presentation needs, and I would be disappointed to see it discontinued.
-- ron mistretta (email)
This is not a just image, it is just an image.
(Jean-Luc Godard 1930- Colin MacCabe Godard: Images, Sounds, Politics (1980))
One of the problems confronting medical and specifically dental images is their ability to be manipulated.
As you can imagine digital images with the possibility to be changed pixel by pixel provide a special verification challenge.
Some Dental Board Certification examinations require that candidates send an undeveloped roll of film of their patient cases to be processed by the examiners independently and projected simultaneously with identical slides processed by the candidate on exam day.
The aim is to rule out any image editing.
By taking on digital projection without an alternative are we throwing out the baby with the bathwater ?
-- Patrick Sequeira (email)
It is interesting the first response should come down to image integrity. Unfortunately, technology makes even the analog slide projector open to potential misuse.
Most copy houses can print digital files (even powerpoint foils!) to 35mm slides for $5 a slide. The integrity of an analog 35mm slide cannot be validated with any more authority than a digital image. However, with a pure digital format we can start do do some interesting meta data checking on files as they are shared.
This same issue came up in the linkrot thread. The validity of an original document is called into question, when documents on computers are easily copied, modified, shared and even lost.
My thought was that the academic world needs its very own Gnutella network with a layer of secure author control over file versioning.
While the issue discussed in the linkrot thread is a bit different, the discussion applies here. I posted my comments from that thread here if anyone is interested in hearing more: http://www.pixelplay.org/jeff/academicFileSharing/
-- Jeffrey Berg (email)
To scan a 35mm slide (film) for high-quality printing reproduction at enlarged sizes requires from 5 to 30mb; at its best, the 35mm film slide has a lot of high-resolution information, now just being approached by high-end digital cameras.
A great virtue of carousel slides was the ability to use dual slide projectors, which provided high-resolution spatial comparisons. Indeed, that analogy is used in "The Cognitive Style of PowerPoint" in order to break out of the temporal sequencing of PP and to increase spatial resolution.
Even in the days of slide projectors, I combined xeroxed handouts with projected color images. And then, more recently, printed color images in handouts.
The carousel certainly had its difficulties and inconveniences--loading of slides upside down and backward (is that right?), munged edges of slides with multiple use (causing the slide to jam), too much light in the room, touchy and very hot light bulbs, some problems with archival quality of slides after repeated projection, and difficult projector/screen relationships in many rooms not originally designed for projectors. Of course a few of these problems are common to any projection method.
One of the few successful uses of PP is as pure slide projector, at least for images that do not require superb resolution.
-- Edward Tufte
It is certainly the case that digital projection shares many of the problems of analog (e.g.: where are the switches for the house lights?). However, the upside-down or backwards problem has tended to be a matter of training. All the geologists I know place a dot on each slide to indicate orientation (if right- handed, your thumb covers the dot as you drop it into the slide tray).
But here's an important difference between the media: at the Geological Society of America, the "speaker ready room" is actually a large room filled with projectors and light tables. This is where presenters actually create the final form of their "papers." Of course, there is no paper. There are only the slides, which serve as mnemonics for packets of information (and even 'jokes'). When the slides are removed from trays after the meeting, the "paper" vanishes. This, of course, has its pros and cons.
The problems with this are fairly obvious. The pros include the ability to edit a presentation at will, up to the point where one has finally to leave the speaker ready room and go to the session. It would take a very confident person, indeed, to continue to edit and revise a PP presentation right down to the wire.
-- Mark Hineline (email)
Here is the complete notice:
July 14, 2003 Kodak Pre-discloses Plans To Discontinue Slide Projectors and Accessories in 2004 Eastman Kodak Company has confirmed plans to discontinue the manufacture and sales of slide projection products and accessories in June of 2004. This early disclosure is being made to key user groups in order to allow time for adoption of a replacement technology or purchase of backup slide projector products.
The KODAK products included in this event are CAROUSEL, EKTAGRAPHIC, EKTALITE and EKTAPRO slide projectors and all KODAK Slide Projector accessories. The current plan is to cease manufacturing in June 2004. Kodak anticipates that small quantities of new Carousel, Ektagraphic, Ektalite and Ektapro slide projectors will be available through the end of 2004. In addition, the Kodak distributor, Comm-Tec, in Germany plans to sell Ektapro projectors and accessories beyond 2004. Kodak will offer service and support for slide projectors until 2011.
Slide projectors continue to be used in many government applications due to a proven track record of cost-effective, reliable, high-quality image projection. Combining the seven years of service and support with a long history of trouble-free operation, means that slide projectors will continue to enjoy many years of productive use.
Investigating and installing replacement technologies can be a challenging and costly effort with a long implementation timeline. So, many may wish to purchase backup units for currently installed slide projectors while making the transition. Upcoming government budgeting activities make it prudent to pre-disclose now in order to allow ample time to include slide projector demand in the government budgeting plans for 2004.
Making Kodak aware of your future requirements will insure that there is enough products on hand before production ends. You can do this by contacting Glenn Prince, Kodak Account Manager, Government Markets (678) 339-0723, firstname.lastname@example.org .
-- Dan Meatte (email)
Mark, I had to respond to your comment "It would take a very confident person, indeed, to continue to edit and revise a PP presentation right down to the wire."
That's the problem I've seen - people preparing PP presentations immediately before delivery. I've seen this countless times in industry and academia. And they may be confident, but their confidence is almost always false: their presentations are rubbish - if they work at all.
My biggest gripe with PP (and all MS Office software) as a tool is its flakiness when files are moved from machine to machine. If the fonts don't match exactly, your presentation can be completely stuffed. If you forgot to "include" that graphic, you get a blank box.
Give me professional graphics tools and Acrobat any day. (or maybe Apple Keynote...when I upgrade my machine to one that will display its presentations!).
Funny how so many ET comments get back to PowerPoint...
-- David Glover (email)
Mr Glover makes the important point about adequate preparation in advance of any presentation. This a sine qua non for any effective speaker.
Mr Glover then asserts that 'their (PowerPoint users) presentations are rubbish...'
I have two questions that might help determine the validity of this assertion:
1. What is Mr Glover's definition of 'rubbish'?
2. What data can Mr Glover adduce to compare the proportion of presentations that are 'rubbish' (thus defined) between users of PowerPoint and non-users?
Unless we can measure what is being asserted, the debate falls back repeatedly to impression and anecdote.
-- Dr Mark Reilly (email)
Not everything worth discussing is quantifiable, but ET has made some quantitative comparisons of Powerpoint to other modes of visual display in his "Cognitive Style" essay. While the comparisons do not allow a calculation of the 'proportion of rubbish' for each, Powerpoint does not fare well in these comparisons, and thus the evidence for its deficiencies is more than anecdotal.
On the topic of Carousel projection, I saw a wonderful talk in Milwaukee last night on Amazonian amphibians and reptiles, in which the speaker's beautiful photographic slides of these animals were rendered washed out and low-res by scanning them into Powerpoint. Although Powerpoint did allow several images to be shown simultaneously, he would have been better served by multiple Carousel projectors. Their loss will be mourned by all who care for high quality display of images in scientific presentations.
-- Gregory C. Mayer (email)
About 2 years ago I started using a LCD projector for my presentations and retired my Kodak Carousel. I'm a photographer, so I don't use charts, graphs, or text slides. I show only examples of my photography, photographs taken of my sets in the studio, and a few sketches, drawings or other visual documents. I use Power Point, but I think of it only as a very flexible and versatile "carousel tray", never as a method of formatting charts, graphs or text. My photography is large format, so I'm sensitive to issues of resolution and color fidelity, but when my work is published in print, some of that quality is lost, and 35 mm slides of that published work projected through a Kodak projector is often dismal; slide are dim, become discolored and caked with dust, and are rarely in focus edge to edge. These problems are exacerbated with an audience of 100 or more.
With the LCD projector, the relatively low resolution is mitigated to a large extent by increased brightness, edge to edge sharpness, keystone correction, and large image size I can put on the screen. When a particular detail in a photograph is important I can easily show an enlarged detail in a subsequent slide. I generally don't use "transitions" except for an occasional smooth dissolve in a step-by-step sequence. I use one Quick Time VR movie that makes an object appear to rotate on the screen, and I show one 25 second Quick Time movie of a set I made with moving parts (somewhat like the Honda Cog ad). These are not gratuitous tricks, they are "escapes from flatland" to make points about visual perception or cause and effect.
Color fidelity issues are mitigated somewhat by making "slides" from cut-down files of my original hi-res scans, rather than scanning 35mm copies of my work. I bring my own projector (an Epson 810p) which is almost always better than the one provided by the venue. Although the LCD projector will not likely match the optimized performance of a conventional projector any time soon, for the above reasons, I will not likely be using the Kodak Carousel again.
As to high resolution vs. low resolution displays, when referring to projected images, perhaps one should compare the "screen resolution" as perceived by an audience of X size, not the resolution of a 35mm slide itself, for it's only as good as it's weakest link.
-- W. Wick
I am interested to know if anyone on this board has experience with high-resolution digital image projection? I work with an artist who does photorealistic paintings of national monuments and needs to project images onto a 6' x 6' surface as part of his working process. In the past he has used 35mm slides successfully, but since the images are available digitally now, projecting the digital image directly would save a number of steps and free up the process. The images are of sufficient resolution, but unfortunately the video hardware is not, yielding only a very pixelated image, when viewed from close range, in all of our tests. Does anyone have any experience projecting very high resolution digital images on a digital set up? Has affordable technology just not gotten there yet?
-- Luke Gilman (email)
I was very pleased to read the experience of W. Wick.
Can we get a link to se your work?
John S. Hansen
-- John S. Hansen (email)
I never had a carousel projector. They came out after I had the earlier style. I still have my AIREQUIPT projector along with dozens of Airequipt slide magazines, each holding 36 color slides. I am not a professional photographer. I just started becoming interested in taking pictures when I went into the US Army in 1957. My problem now is although I still have the projector, it no longer works. I do not think the company is still in business. Any ideas as to obtaining another projector that will take my mags?
-- Larry Wilson (email)
A well know internet auction site often has vintage projectors and accessories listed. I found a lifetime supply of bulbs several years ago for a tenth of what one new digital projector bulb would cost.
-- M. Reasor (email)