DLP Technology, Features & Installation

Up until now I have found that most "dual use" projectors are more designed for the office or school and not so much for the home theater. In the case of the Optoma EP1690, we may have found the first unit capable of actually performing well in both situations. We can place the thanks for this partly on Optoma and partly on the advancement of DLP front projection technology which allows for greater contrast, better output levels and performance options not found a couple years ago. I'll outline the strengths and weaknesses of the EP1690 below, but I have to say that I am impressed overall and I could see a lot of office managers and teachers wanting to take this unit home from the classroom each night for "safe keeping".

DLP Technology

I've gone over general DLP technology in the past, so let's focus on the system found within this specific Optoma model. The EP1690 utilizes a 0.65" DDR (Double Data Rate) DLP chip. These chips increase contrast ratios by as much as 20-50% (potential, not actual calibrated performance) by:

• Increasing the mirror's tilt angle from +/- 10 degrees to +/- 12 degrees
• Increasing the amount of image data the chip can receive per second
• Increasing the amount of speed at which the micro-mirrors can move (related to the above data rate)

These new chips are utilizing what's known as "Dark Metal" technology (sounds kinda Sci-Fi doesn't it?) to essentially capture stray light that may escape to the underside of the chip (and thus to the screen which reduces contrast). The result is DarkChip2 tech which does seem to be making a noticeable difference in the perceived images we've seen from these "next generation" displays.

Features and Favorites

I like to go through the features that I feel make a unit stand out among its peers. In this way it's easy to spot things that you really need or useful functions that may surprise you.

• Built-in 3W speaker
  A necessity for use in multimedia presentations, the presence of an on-board speaker makes this projector fit for "taking on the road". While only 3W, it was plenty loud for our use and, provided you're not trying to entertain or educate an auditorium of listeners, you are sure to have enough volume for more intimate settings.

• DVI-D with HDCP support
  While HDMI with audio processing capabilities would have been "off the hook" , the presence of an HDCP-compatible DVI-D input is welcome and ensures that this projector is fully home theater compatible. What's more, the DVI-D connector is much more stable than HDMI, so you won't have to worry about a loose connection interrupting a presentation.

• 16:9 and 15:9 pixel mapping
  While most projectors these days come in 16:9 native resolutions, rarely is any thought given to remapping pixels for display of both 15:9 (common PC resolutions of 1280x768) and 16:9 (720p) formats. The EP1690 will correctly map the pixels in both formats, making sure that your images are in the proper perspective.

• RGB Gain/Bias user controls
  Since we really value user calibration of projector systems, it's nice to see RGB gain and bias controls that aren't hidden in the service menus. This is especially important with new calibration tools like DataColor's SpyderTV Pro hitting the market which make home calibration of projection and direct view systems more affordable.

There are many more features to be sure, but for now these really stood out to me during the use of this projector.

Basic Setup and Installation

Like many Optomas, this projector is a bit difficult to mount using a tabletop, due to its very high projection angle 舑 a potential concern when using it in the board room or for classroom instruction. Ceiling mounts are always preferred if this is appropriate for your particular room, but this reduces the "dual use" potential of this projector. For this review we utilized a Stewart Luxus Deluxe ScreenWall system with a StudioTek 130 100" diagonal screen. This is an excellent quality screen which is optimized for perfect color in a light-controlled room. Take a look at the 16:9 throw chart to see how the Optoma will work in your situation:

Throw Chart for Distancing the Projector from the Projection Screen

The first thing to note is that the EP1690 doesn't have much of a zoom range, so you'll have to carefully plan out the distance required to hit your desired screen size. Combined with the steep throw angle of the unit, I'd say this would be one of the more difficult projectors to place were it not for the excellent digital vertical keystone adjustment available in the unit. The ability of the projector to compensate for angle makes up for the difficult placement parameters. In fact, the only issue that remained was the lack of range in the feet leveling. When used as a front projector on a tabletop, the rear feet really need to be able to extend to about 3-4 times their current range (which is a laughable 3/8-inch.)

We positioned the projector in a temporary, but workable location. It was centered horizontally with the screen and set back exactly 11.5 feet - at the extreme of the wide setting for the lens. The projector had to be mounted almost ridiculously low in order for the high projection angle to hit the bottom of our screen without keystoning. By low, we mean that a 20" tall table didn't work for us. For ceiling installations you will have to ensure that your screen is mounted low enough on the wall to allow for a keystone-free installation.

While we're on the topic of keystoning, realize that while it will help you to have a more square picture to the screen, it will also result in a "dithering" of the image. This means that if you have a 1-pixel wide line of black next a 1-pixel wide line of white you will see three lines as soon as you initiate vertical keystoning. The third line will be the interpolated grey as the image seeks to re-render itself in the new position. This isn't the end of the world, however and the softening of the image can actually be beneficial for those sitting too close to the screen and subject to seeing the individual pixels on the screen. In some configurations, keystoning will be necessary, however we encourage you to avoid it if possible.

We ran two different cables to the projector for our tests. We rolled our own component video cable from materials supplied by Blue Jeans Cable and a well-built HDMI cable (supplied by DVIGear) enabled us to compare the digital video connection from our reference Denon DVD-3930CI player. An HDMI to DVI converter from Gefen, Inc allowed us to go from HDMI to the DVI-D input on the EP1690.