Proxima DP6850 Digital Projector
Michelle Manafy & Adam C. Pemberton
Proxima DP6850 Digital Projector
synopsis: While the Proxima DP6850 didn't earn the highest marks for video presentation, it proved a solid performer overall. It offers a variety of computer-friendly features that make it well-suited to mobile and desktop use as well as crystal clarity in textual applications. While it might not be the perfect choice for someone with heavy video demonstration requirements, especially if image fidelity and color saturation are essential, the DP6850 is a great choice for presenting computer graphics, line drawings, and spreadsheets, and will certainly meet the needs of anyone with less exacting video requirements.
9440 Carroll Park Drive
San Diego, CA 92121;
July 2000 | The parent company of EMedia Magazine, Online Inc., sponsors several conferences, one of which many of you will know: DVD PRO. This requires us to purchase some pretty swell equipment in the line of duty including projectors, which we use at the shows for speaker presentations. Many of these presentations are delivered using PowerPoint and the like, but let's face it, these folks are DVD pros. As such, they have a propensity for using DVD-Video in their presentations. This requires us to choose our projectors based on some pretty specific criteria. Because we've looked at quite a few, we've developed some guidelines on what works and what works well for presenting DVD.
Our reference projector at Online--the machine that best suits our DVD presentation needs--is the Epson PowerLite 7250. The Epson is street priced around $6,000, and is rated at 1300 ANSI lumens. It is admittedly not a price-is-no-object solution, but it does a good job with computer graphics, and an excellent job with video. Thus, in reviewing the Proxima DP6850, our evaluations are made with respect to the reference unit. We used Ovation Software's Avia Guide to Home Theater DVD to calibrate the Proxima's white point, black point, saturation, and hue to the Avia targets.
The Proxima weighed in at 13.4 pounds, which makes it nearly as fashionably light as its advertised 13.2 pounds. The audible noise from the projector's fan is specified at 40db; and it was indeed one of the quietest units we've heard (our research indicates the quietest unit on the market is 38db). The Proxima features built-in speakers, useful in limiting audio carry-ons required for making a presentation off-site, though 1-watt stereo speakers will certainly not suffice for installed or auditorium usage. It ships with some other good-for-traveling accessories like US, UK, and European power cords, serial, PS/2, and ADB mouse cables, and a MAC adapter. One accessory that we've found indispensable with our projectors is a lockable ATA (American Trans Air) approved, rolling hard case. In addition to Proxima, any number of quality third-party vendors (Targus, Case Technologies, Inc.) can provide a variety of case options.
Ease and functionality of the remote are very important to the operation of a projector. The Proxima has some key features like zoom, mute, and focus tucked away under a panel, in addition to an easy-to-find laser pointer on the top of the remote. Accessing and navigating the Proxima's menus for adjusting image parameters is straightforward and intuitive. The menus for inverting the image horizontally or vertically (to accommodate ceiling or rear-projection mounting) are clear, after some experimentation: in contrast, the Epson names these menus "Ceiling Mount" or "Rear Projection," which we find more straightforward than "invert horizontal." For sheer coolness, the Epson remote wins for its unique variation on the pointer: pressing one button serves up an on-screen animated arrow; moving the uni-directional joystick then moves the arrow, which can also be frozen in place. Subsequent arrows can be placed at different points on an image.
Getting the Proxima up and running was quite simple. The unit offers two RGB computer inputs, one composite video, one S-video, stereo audio, and one USB mouse input along with one RGB computer and stereo audio (mini-plug) outputs. Unfortunately, at least with regard to the obstructing bracket on our ceiling mount, all of the power/input/output connections are made on the side rather than on the back. This would likely not be a factor if the Proxima is used on a tabletop, or in a custom installation. The Proxima offers 20 degrees of keystone correction, fit-to-view digital scaling, and a native XGA resolution of 1024 x 768. It also supports SXGA, (interpolated), SVGA, and Mac resolutions.
adjusting the image
Clarity of a projected image is not simply a question of lumens--the Proxima specs claim 1500 ANSI lumens, which is close to our Epson's boasted 1300 rating--it encompasses many aspects of color and contrast. The Avia disc provides test patterns for adjusting contrast/white level, brightness/blackness, sharpness, and saturation/hue, all of which greatly affect the fidelity and accuracy of an image. These are highly inter-related settings, often requiring a series of secondary, compromise adjustments to arrive at the optimal image. One important projector attribute is contrast, which measures the maximum relative contrast between black and white. The Proxima's rating of 100:1 seems to hold back its video performance as compared to the Epson, which has a contrast of 200:1.
Ultimately, the Epson offered near-ideal brightness and contrast by setting brightness at zero and the contrast at minus one. We did get a very good result for contrast with the Proxima at +3, however, we could not achieve optimal brightness at any adjustment of the settings. In comparing the black/50 percent gray screens, the Proxima's black appeared significantly less so than the Epson's, and the Proxima's gray was brighter and slightly blue.
Both models achieved similar results when calibrated to the sharpness target, although the Proxima appeared to struggle with the extreme fine detail. These regions of the target, when projected by the Proxima, appeared to strobe much more noticeably than the Epson. The Proxima calibrated accurately to the hue/saturation target, although only after markedly increasing the tint.
Both the Proxima and our Epson employ three 1.3-inch Polysilicon Liquid Crystal Panels (LCD). Most polysi designs use three separate panels for the red, blue, and green images, and a series of lenses, prism, and mirrors to merge the three on screen. The result is a bright image, but this mechanical arrangement requires a good degree of precision in assembly alignment to achieve good convergence of the three images. Convergence is something that should be checked right out of the box because, unlike CRT devices, LCD devices cannot be user-adjusted to correct convergence.
We tested convergence using a custom-designed calibration target. In this area, the Proxima earned high marks. Near the center of the target, there were no visible lines of color (when the three color panels are not perfectly merged, one color will appear as a separate line above or below the white lines of the target). There was a green line visible above the target in the upper left of the test screen and at the outer range of the right side of the test screen. Needless to say, the visual impact of this line is minimal--a result that was evident in the sharpness calibration. (For comparisons sake, the Epson also had lines appear at the outer edges of the test screen; in fact, they affected slightly more of the screen area than did the lines on the Proxima.)
consider the application
Depending on the intended usage of a projector, its performance playing back DVD-Video or in viewing text-based presentations will weigh heavily in its value to the user. As previously stated, we place a good deal of emphasis on the appearance of DVD-Video in the selection of a projector. We ran some side-by-side comparisons (to the reference projector) of DVD movie and landscape video to gauge the Proxima's performance. Video projected by the Proxima did not exhibit any more than slight artifacting, which took the form of slight haloing at the transition of a silhouetted object to its background. However, when compared to the Epson, the Proxima video lacked a richness of color and fidelity. Landscape images were washed out, white highlights lacked detail, shadow areas were muddled. This is a highly subjective observation at best, but the opinions of every staffer who looked in confirmed it: the video looked decent, but not true to life on the Proxima. This is one area where the Proxima performed quite differently from our reference unit, and it may be partly explained by their different contrast ratios. The reference Epson also replaces the earlier 7200/7300 series, and sports a new digital comb filter to enhance color saturation.
Where the Proxima really shined was in a comparison of textual presentation. In a text-dense spreadsheet, the Proxima produced clear, readable text even with magnification. Characters were less sharp when viewed through the Epson, and although only 200 lumens separates them, the Proxima image was noticeably brighter. For delivering a PowerPoint presentation, the Proxima makes an excellent choice.
A couple of off-the-specs issues that factor into our projector choices around here are the negotiability of the warranty and whether or not the unit is manufactured by the vendor or is a VAR product. We've learned that traveling with a projector and putting it to hard use make warranty duration, as well as the vendors' ability to repair the product themselves, highly valued. The Proxima comes with a two-year warranty on parts and labor (excluding lamp) and offers two optional extended warranty plans. Proxima does manufacture its own products and, as such, should have more flexibility in its ability to make repairs.
While the Proxima DP6850 didn't earn the highest marks for video presentation, it proved a solid performer overall. It offers a variety of computer-friendly features that make it well-suited to mobile and desktop use as well as crystal clarity in textual applications. While it might not be the perfect choice for someone with heavy video demonstration requirements, especially if image fidelity and color saturation are essential, the DP6850 is a great choice for presenting computer graphics, line drawings, and spreadsheets, and will certainly meet the needs of anyone with less exacting video requirements.
A DVD Presenter's Wishlist
The list of essential features in a projector that will be used to present high-quality DVD source material is surprisingly simple. Use this checklist to measure any projector you are considering:
- The ability to project video of any kind accurately. This is the most subjective test of all, and absolutely requires an a/b comparison of multiple projectors. Start with your sales rep, or do the research yourself in the trade press, but get a short list of models that are known for delivering good video. Then run the same signal through them all.
- Component inputs and HD-compatibility. Your DVD-Video player can deliver a higher-fidelity video signal using these inputs than with the composite signal coming from your VHS deck. Use the better signal source.
- A quiet fan. We've used the Epson 7250 in home theater screening environments, and its 42db fan is too loud for subtle vocal sequences. This is not an issue if you are building a custom enclosure and can route the heat (and noise) away from listeners. If your projector is in the open, look for the quietest fan, which is usually one between 38 and 40db.
- Bright projector, dim lights. If you can't control your lighting (turn off diffuse light sources, such as fluorescents, use directed spots, no light washing the screen), you ought to select a projector that can deliver 1500 plus ANSI lumens in mind. Like horsepower, there is no substitute. If you can control your lighting, then 1200-1500 lumens will work fine, up to a 15-foot screen width.
- Two other considerations are: screen material and size. A screen with a reflectivity value of 1.0 does not amplify the light reflected from it, and has good off-axis viewing properties. A screen with a reflectivity of 1.5 or greater collects the light projected on it, and focuses the reflected image in a concentrated area that is best viewed on-center. This is better for high-ambient light conditions, but seating location becomes important.
- The size of the screen, and thus the location of the projector (a calculation based on the focal length of the lens, throw-distance to the screen and other factors), should not be chosen randomly, or just based on how big the room is. The formulas used by designers of presentation systems and theatres are different, as each application places a different emphasis on the requirements of video and projected graphics (e.g., a presentation system will require computer text to be readable from the back row).
- To arrive at the correct screen width, height, distance to first row, distance above the ground, etc., for your particular application, check out the following two Web resources: Schneider Optics (a maker of theatre lenses) has a free downloadable program that calculates picture size, lens focal length and image shape due to keystone distortion and screen curvature, available at http://schneideroptics.com/theatre/desprodn.html. Another screen size calculator can be found at http://www.mcsquared.com/images1.htm. This Java applet is much simpler and is tuned to the needs of graphics presentations instead of theatre/video. The screen vendors themselves are also good resources for this type of information.
Michelle Manafy is Associate Editor of EMedia Magazine. Adam C. Pemberton is Publisher of EMedia Magazine and President of Online Inc.
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