In praise of document cameras–OHP RIP

One of the mainstays of 20^th century audio-visual is the overhead projector (AKA view graphs to those with military backgrounds). As a matter of fact they're having remarkable staying power in the 21st. As with most technologies these days, it's being overtaken by a more flexible and convenient technology, the document camera.

Overhead projectors have been nearly ubiquitous in classrooms. It was fairly easy to create a transparency for them, first with a relatively inexpensive machine that used infrared energy to create an image on the film, and later with copying machines and laser printers. Of course, if you had just a plain piece of acetate and a suitably sticky writing instrument, you could just write on them. They were the paragon of reliability. The major failure was burning out a bulb, but many models had a lever that would just change to a second bulb. From the banner above this blog, you can see that I still have some affection for overhead projectors, but I really don't have much use for them anymore.

There were downsides. The main one, of course, is that in order to use a transparency in class you had to make the thing first. The material and appropriate machine isn't always right handy. They're a little bulky to carry and store. And, they cost fifty cents to a dollar each to make.

One thing that always bothered me is that the projector always seems to be askew from the screen, and projects a distorted image (Keystoning to you AV Club members).

Document cameras are taking over the role of overhead projectors, and as with a lot of the digital revolution, provide additional capabilities and flexibility.

A document camera is basically a digital video camera that's mounted to point straight down at (you guessed it) a document. Any document—a sheet of paper on which you can write with any instrument you've got handy, an editorial cartoon in this morning's New York Times, the post-it note with a lame excuse a student left on your office door. You don't have to make a transparency, you just use it the way you found it. You can even put your overhead transparencies on it, although the shiny plastic may reflect the lights above the camera.

The document camera is connected to a video/data projector that projects on the screen, and in a permanent installation, it's always fills the screen and is straight and undistorted.

Zoom lenses provide a range of magnification so you can zoom in on the fine print, or out to fill the whole page.

Early document cameras got a questionable reputation because they used plain old TV cameras which had a maximum resolution of about 400 lines and type could look pretty fuzzy on a full page view. Current document cameras use digital cameras that are probably sharper than the projector you view it with. (Although you'll probably still have trouble reading a full page of text, but, let me clue you in, your audience couldn't with an overhead either.)

Things start getting really cool when what you want to show the class isn't a flat piece of paper, but maybe a bug, a chemical reaction, or a medical device. Three dimensional objects work just fine. At UW Oshkosh, we've installed a few document cameras that have the electronics in a small box on the side so you can put a pan full of chemicals under it without worrying that a small leak will kill the electronics. (If you spill a cup of coffee on it, however, it will kill the electronics—ahem!) Many document cameras also have a tilting head so you can turn them and use it like a conventional television camera. Some can even be pointed into the eyepiece of a microscope.

The big downside is the cost. Not only do document cameras themselves cost more than an overhead projectors, but they need to be connected to a projector in order to be any use. The cost of the document cameras themselves have come down recently, and it's likely that the classroom already has a projector available to project a computer image. Another downside is that you can only present one device at a time on the projector so you have to somehow switch between the two devices as you use them. This is usually done at UW Oshkosh with a control panel in a fixed place in the front of the classroom, but some of the larger lecture halls have wireless control panels the instructor can carry around the room.

At UW Oshkosh we have document cameras installed in the larger lecture halls, and are deliverable as needed to smaller rooms.

In our planned new academic building, document cameras are going to be really integrated into the system. Every classroom will have two projectors, one for the computer, and one for the document camera (as well as the capability to view DVD's and whatever else they're going to invent). In addition the screens will be above the whiteboards, so they won't impede the instructor's ability to write on the board. And there won't be any overhead projectors.

You can't always get what you want, but....

Sometimes you do get what you want. This is a little bit of a long story involving the history of classroom technology and the sometimes labyrinthian budgeting of the University of Wisconsin System. The large lecture halls on our campus were some of the first rooms to be "technology enhanced," which means to have some sort of projector installed which will serve up the screen from an installed computer, the screen from a user supplied laptop, video from tape or DVD, maybe a document camera, and some way to control all these devices. At this point in history, some of them have been through one upgrade since being first enhanced in the early to mid 90's and are now due for another upgrade, and a couple for odd reasons have only been half enhanced (I'll explain as the story goes on). It seems like every time I have attended an event in a classroom in the past several years, I was grossed out by how dim the projectors were. In a statewide conference that we hosted last year, the presenters had to keep changing the lighting from "presentation mode" to "off" so the audience could get a decent look at the photographs in the presentation. I felt like everyone was looking at me wondering why the projectors were so lousy.

So, for the last few years, I've been focusing on upgrading these big lecture halls where so much instruction takes place.

I have to mention a lot of the smaller classrooms also really need upgrading too. (see an earlier post) The primary source for funds to install technology in classrooms is the Classroom Modernization Fund, which was established in the early 90's to enhance classrooms with the then new technology of digital projectors for computers, which could also project video, which had almost 100% replaced 16mm film by then, but until then almost had to be viewed on a television set, which made things a little tricky in large lecture halls.

Sometime around 2002, we started utilizing this money to replace computers and projectors which had been purchased with this fund. The number of classrooms which have projectors and computers in them has grown quite a bit, and in recent years, most of the Classroom Modernization Fund has been dedicated to replacing computers and projectors, and especially due to a perfect storm of funding to install new classrooms in 2002-2003, we currently have more equipment that needs replacing than the Fund can handle.

But, there are other sources of funds that can be used for Classroom Technology.

The Clow Pits are three lecture halls that have had special problems for installing technology. One of them was technology enhanced in the mid '90's. The stage area and most of the seats are only accessible by stairs, which means they're not ADA accessible, and if you want to remodel them they have to be made ADA accessible, but because of the way they're sort of buried into the ground surrounded by city and university utilities, this was so expensive to be out of reach, so there they sat without much technology. In the two rooms that had no installed technology, we put a projector on a cart in the front of the lecture hall, which worked OK, but it's inevevitable that when you say loose cable, you often also have to say risk management, and if the instructor didn't trip when wandering around the stage, they had the projector shining on them, and casting a shadow on the screen. Another issue was that we could get the projectors only so far from the screen, and even with an expensive wide angle supplementary lens, the image was a little small for the room.

Now these rooms had projection booths in the back from the era of 16mm projectors where we could place projectors (without "remodeling"), but a data projector needs about a 1/2 inch diameter cable running from the computer to the projector, and there is a distance limitation. This distance limitation could be overcome, but we're talking about even more expense. Recently, however, someone invented a relatively inexpensive technology where the video and control signal would be sent to the projector with Category 5 cables (your computer is connected to the internet with a Category 5 cable), which are much easier to deploy these kinds of distances than a proper video cable. Also about this time, the the video projector in the one of these lecture halls that been installed failed early in the semester, and because it required building scaffolding to get to the projector hanging from the ceiling, we had to put a projector on a cart in that room too.

This came to pass after the deadline for submitting Classroom Modernization Proposals for that year, so even if I did have money in that Fund, it would be a year and a half before we could make these improvements. Well, we also have the Student Technology Fee in UW System. Each student pays a certain amount that is supposed to be dedicated to increasing student access to technology. I had always refrained from addressing the Student Technology Fee for classroom upgrades, because the guidelines for that Fund explicitly exclude that type of use unless a committee composed of students (which we do have at our institution) decides that's what they want to do with it. The previous year they had decided to put aside 10% of the fund to purchase classroom technology in a new academic building which will open in 2011, so that seemed like they were amenable to this kind of expenditure. I made the proposal for these three problematic rooms, and they went for it! The upgrades took place last winter. Not only are the projectors more conveniently (and safely) located, and their controls were more consistent with what we have in other classrooms. but we also specified higher brightness projectors which put a very nice image on the screen even with the room somewhat illuminated.

I should say something about the brightness of projectors. The image in these big lecture halls is over twice as wide as the image in a normal classroom, so the light is spread over an area more than four times as great, and if the projector brightness is equivalent, it's four or more times as dim. In the past, high brightness projectors were available, but were four times the cost of a normal room projector, so we always had installed the same projectors in the lecture halls and just accepted that we would have to turn the lights almost off to see a good image. Considering that people still had memories of turning the lights completely off to view 16mm films and slides, that wasn't so hard to accept. Several things have changed since then. In the first place, the projector is in use for almost the entire class today, so sitting in the dark is more of a bother. Secondly, projectors are much brighter in general, and higher brightness projectors intended for these large venues are now only a little more expensive than the ones for normal classrooms.

Now to another set of lecture halls, this time two rooms in Halsey Science Center. The technology in these rooms had been installed as part of a building remodeling project in 2001. The outside vendor who did the installation frankly did a lousy job. We almost immediately replaced the portable projectors they had hung with heavier duty models, but those are now getting old, and as mentioned earlier, are kind of dim compared to new projectors. We also had a problem with the control system. The programming of the control systems in this case was done by the vendor, who retained the rights to the programming, so if it needed changing, we had to go to them to get that done. This is not an unusual arrangement, but it is getting to be less common. What really capped this off was the vendor went out of business without giving us the programming, so any change would require starting from scratch, which is a bit of expensive programming. Somebody dropped one of the control devices several years ago and we had quite a scare that we would wouldn't be able to recover this programming. Also at issue is that newer control systems now have less complicated programming which was easy enough to learn that our technicians could pick it up in a three day training session.

I had proposed improvements to these two lecture halls to the Classroom Modernization Fund, but before the time came for the committee to review that proposal, another of the UW System's funds entered the stage. There is a Classroom Renovation Fund, which in the past was distributed to the campuses annually, but now is distributed on an irregular basis. It allows for installation of technology, much like Classroom Modernization, but also covers a wide range of remodeling and infrastructure improvements that Classroom Modernization does not. Since it is the prime source of funding for these extensive remodeling projects, our Facilities Management group is loath to use it only for technology improvements. Last year, we received a larger chunk of this fund than we had been getting, and Facilities decided to use some of it to make the improvements to these two lecture halls that I had recently proposed for Classroom Modernization! (It turned out this had to be delayed a year, but the improvements will be done this summer) Five lecture halls down and three to go!

Now to the lecture halls in the Nursing/Education Building I had been embarrassed in that I mentioned at the beginning of this post. They also had older, dimmer projectors, and also had older, although still working and reprogrammable, control systems. Complicating this one were limited inputs on the control system. These older control systems really couldn't add a new device. If you wanted to use a laptop, you had to take the video cable from the installed computer, and plug it into your laptop. In addition, we had added a document camera in there which had a feature where you could plug the computer into a port on the document camera and if the document camera was off, the projector displayed the computer, and when the document camera was on, it displayed the document camera. This allowed us to add the device, but to put it mildly, this was a sub-optimal user interface. More than a few guest speakers lost a chunk of their available time trying to get their laptop image on the screen.

Well, the Student Technology Committee had been so forthcoming with the Clow Pits, I made the proposal to them for these rooms. What a difference a year makes when working with a student committee. This year's committee not only didn't approve the proposal, they were a little offended that I even tried to take such advantage of them when I had other funds (however inadequate) for classroom technology.

But, the committee didn't make this decision for about six months after I had proposed it, and during that time I was pretty confident it would get funded. I began to worry about that last lecture hall, the largest one in Halsey Science Center. This was the first multimedia classroom and a big showpiece when it was first installed in 1992. The original design was pretty good. It's always been popular with faculty because it has two projectors. You can show a video on one and the computer on the other, or the installed computer on one, and your laptop on the other (this is the science building, ya know). We had replaced the projectors once and updated the control systems two years ago. but I worried if I got all those other lecture halls upgraded with new, brighter projectors, this room was going to look pretty dim. I had intended to make this my highest priority in the next Classroom Modernization cycle although that meant it wouldn't happen for a year and a half.

Enter the last budgetary player, End-of-the-Year Accounting! It's a little frightening when I think about it too much, but especially in Information Technology, there can be quite a bit of difference from what you plan on in a budget, and what you actually have to do with that budget. Happily some costs go down unexpectedly, less happily some staff leave and you have salary savings, and you always stick something in there in case something unexpectedly breaks, knowing that you'll probably have new needs you hadn't thought about if nothing does break unexpectedly.

This year, our IT division was on the happier end of that equation and at the end of the fiscal year we identified a good bit of money, and my boss decided to fund the Nursing/Ed project the Student Tech Fee had rejected and get to that big Halsey Lecture hall a year earlier!

There's some question about where the Nursing/Ed project can be competed this summer, but my wish to bring these lecture halls from their somewhat outdated condition to some pretty neat places to teach is going to be granted. In contradiction of Mick Jagger's famous lyrics, In addition to getting what the University needs, I'm going to get just what I wanted.

In case there's anyone still reading this incredibly long post, and in case any of you are UW Oshkosh faculty, start looking for pictures, videos and web resources to illustrate your lectures next year, because they're going to look really good.

An Optimistic Projection

Easily the most widely adopted technology at UW Oshkosh is projecting some sort of computer image in the classroom.  Anyone who has been using them has probably noticed that the image on a lot of the projectors has degraded significantly.  The good news is we have discovered that many, but not all, will be able to be restored to almost like-new condition.

 

This story mainly involves the NEC GT950 model, which you may recognize as one of the smaller projectors hanging from the ceiling in many classrooms. In 2002-2004 funds from several special sources became available and we added 44 of these machines in new technology classrooms, on carts distributed from our Instructional Technology Centers, and used them to replace some of the earliest installed projectors.  The GT950 represented a new class of mid-range projectors that at $4000 were significantly less costly than their bigger brother, the GT 1150, that we had been installing at $8000 apiece (The latest projectors we're installing are about $3000). They were just about as bright and have some clever image shifting features that gave us more flexibility in where the projector needed to be placed.  Very handy especially for projectors being rolled into classrooms full of tablet arm chairs.

Seven years down the road, we faced the very scary prospect of having to replace this large number of these machines in a very different fiscal climate.  To make matters worse, these GT950's were not aging well.  Their overall brightness was dropping and annoying large pink splotches were developing on the image.  Based on our experience with older projectors, this was probably due not only to dust and dirt, but also to the aging of the LCD's that create the image in the rather warm environment in the beam of a powerful lamp.  As you might guess, parts are not available for a seven year old projector–ancient in the fast moving projector market.

LCD projectors are fiendishly complex devices.  The beam from the lamp is split by partial reflecting mirrors into three beams, directed around two to three turns with mirrors, through three separate LCD's and polarizing filters, one each for red, green and blue components of the image and recombined and directed through the lens with prisms.  This involves very precise alignment on more than a few parts. The engineers who design these things do not generally take great pains to put them together so they can be taken apart, and then reassembled with everything in alignment.

We have discovered, however, that this particular model can be cleaned to restore the image to practically new condition.  Because of the large number of these 950's in our collection and the relatively poor image they were delivering, Gary Vandre, one of our electronics technician, started pulling them apart and discovered that virtually every optical surface was accessible and the parts were able to be reassembled with everything still lined up.  The pink splotches are gone, and the brightness renewed to almost new condition.

It's not perfect. On most of them the aging of the LCD's is noticable as a green cast in the lower left of the image, probably due to the green LCD being closest to the lamp.  Also in rooms with heavy chalk use, the chalk dust is almost impossible to clean off the optical surfaces. The cleaning technique is to blast them with compressed air. Actually touching them and trying to clean the chalk dust off with windex and even the best lens cleaning cloth would scratch these delicate surfaces and knock them out of the perfect alignment need to create a sharp image.

We hope to get to all those projectors we can clean before fall, so the images in your classrooms should be improving soon, and now we know which projectors to concentrate our replacement efforts on and which we can keep in service to smooth out that projector population boom of 2002-2004.