Back in 1996, the brightest "portable" projectors on the market put out about 500 ANSI lumens and weighed 20 lbs. Believe it or not, these luggable dinosaurs were hot at the time. Nobody back then would have dreamed that eight years later we'd have an array of products that were capable of double the brightness weighing just two pounds. Yet here we have the first of no doubt many reviews to come of projectors no bigger than a paperback book.

Included in this shootout are three XGA-resolution DLP-based products that weigh a bit over two pounds each. They each feature a four-segment (RGBW) 2x speed color wheel. The brightest of the three, the InFocus LP70+, is rated at 1400 ANSI lumens. The NEC LT10 is second in brightness at 1100 ANSI lumens, and the PLUS V3-131 is rated at 1000 ANSI lumens.

These products are clearly designed for the traveling presenter for whom carrying weight is a major concern. They can be easily tucked into a briefcase or tote bag, and they make portable presentation more convenient than ever. However, though they are all about the same size, weight, and resolution, there are important differences in picture quality, video performance, fan noise, throw distance and so on. The objective here is to sort out the strengths of each product so that the reader can determine which might be best for his or her needs.

Performance comparisons

ANSI lumen ratings. As is often the case we found that the actual lumen performance on all three models fell short of the published specifications. The InFocus LP70+ measured 1067 lumens, 24% shy of its 1400 lumen rating. The NEC LT10 measured 855 lumens, 22% below its 1100 lumen rating. And the PLUS V3-131 measured 709 lumens, 29% below its 1000 lumen rating. (In addition the V3-131 has an economy mode that reduces light output by 11% and slightly reduces fan noise in exchange for an increase in lamp life.) Thus, though the rated specs are all higher than we saw in actual usage, they do accurately reflect the ordinal ranking of the three products in terms of their relative light output. The bottom line is that the LP70+ is about 25% brighter than the NEC LT10, and the NEC LT10 is in turn about 21% brighter than the PLUS V3-131.

Contrast ratings. Both the LT10 and the V3-131 are rated at 2000:1 contrast, while the LP70+ is rated at 1100:1. Contrast ratio is the difference in luminance value between black and white emerging from the projector's lens. In actual usage black levels on the screen are determined primarily by the amount and direction of ambient light in the room, and not the projector. On the other hand white levels are determined primarily by the lumen output of the projector. Therefore unless you are planning to give presentations in the pitch dark, ambient light will neutralize the differences between these projectors' theoretical contrast capabilities. In normal data presentations usage, despite its lower contrast rating the LP70+ will look just as high in contrast on the screen due to its higher lumen output. But if the projectors are being used in video mode in a dark viewing area, the lower contrast on the LP70+ contributes to lower snap and less color saturation than is found on the other units (more on this below).

Weight. The LT10 is the lightest of the three units, weighing 2.16 lbs. The LP70+ is next at 2.44 lbs. The V3-131 is slightly heavier at 2.56 lbs.

Form factors. Standing just 1.5 inches tall, the V3-131 is uniquely designed as the thinnest projector on the market. It can be carried in a slimline briefcase with no problem. It is 8" long and 6.5" wide. On the other hand the LP70+ and the LT10 both stand about 2.6" tall and measure about 6" length by 7.5" in width, or about a half inch smaller than the V3-131 in both footprint dimensions.

Footer adjustments. In setting up a projector for table-top operation, one often needs to tilt the projector upward to achieve the desired image location. The LP70+ and LT10 achieve this with a single extension foot near the center front of the unit. A button releases the extension foot so that the user can position the projector to the angle desired. On the V3-131, there are two extension feet, one at each front corner of the unit. They must be individually unscrewed to the desired position, and both must be unscrewed to the exact same length to avoid a tilt in the image. This arrangement is more cumbersome both for set up and packing it up than is the case with the other two units.

Video/data signal connectivity. Due to their small size, connectivity is limited on all three units. Each has one computer port that can also be used for component video and HDTV. The LP70+ computer port is an M1-D/A, while the other two units have traditional 15-pin VGA connectors. All three units have one S-video and one composite video jack. In addition, the LP70+ offers wired control via a USB port, whereas the other two products do not.

Fan noise. Traveling presenters most likely to use projectors such as these often find themselves in smaller conference rooms in which a projector's fan noise can be a distraction. We found the fan noise on the LP70+ and the LT10 to be surprisingly quiet considering their extremely small form factors. Fan noise is low and about equal in loudness between these two units. The LP70+ has a lower pitch than the LT10 and is thus a bit less noticeable of the two. But neither unit is objectionable. Unfortunately the same cannot be said of the V3-131. Audible noise on this unit has a much more significant presence due to both higher volume and higher pitch.

Note that the published audible noise specifications on these models do not represent reality. The V3-131 is listed at 30 dB, while the LT10 is 34 dB and the LP70+ is 32 dB. Based upon these specs one would conclude that the V3-131 was the quietest of the three. In fact it is the loudest.

Zoom lenses and throw distances. From a projection distance of six feet, the LP70+ produces an image between 39" and 49" diagonal. The LT10 has almost the same zoom and throw range as the LP70+. From six feet it produces an image size of 42" to 50.5" diagonal. And the V3-131 with its fixed wide angle lens throws a 57.5" image. Thus for any desired image size, the V3-131 requires the shortest throw distance of the three, but there is no zoom adjustment.

Optical precision is not perfect on any of these units. Image geometry and sharpness is best on the LP70+, and the image retains its sharpness throughout the entire range of the zoom adjustment. However the projected image on our test unit was tilted a couple of degrees-not enough to notice on a bare wall, but enough to be evident when trying to square up the image on a screen. However the left rear foot can be unscrewed and extended to tilt the projector and compensate for this if needed.

The LT10's zoom lens does not have quite the precision of the LP70+. At one end of the zoom range the image has a slight convex pincushion effect, while at the other end it has a slight concave pincushion. It squares up well through the mid-range of the zoom adjustment. Any change in zoom setting also requires a readjustment of focus. At any given setting however, once focused the image is sharp from edge to edge.

The V3-131 lens also has a subtle pincushion. When the screen is filled with text from edge to edge the lines of text have a slight arc. Contrast is also higher toward the center of the image than at the edges.

The optical imprecision on the LT10 and V3-131 is not visible at all in graphics, PowerPoint slides, or video. It is only when the subject matter consists of detailed full screen text or spreadsheet data that it becomes visible. And even with this subject matter the errors are subtle and most viewers would not notice them.

Heat generation. Due to the very small form factors of these units, they are all designed to get hot in operation. Radiant heat is part of the cooling plan, so they all get very warm to the touch. This is not a flaw in their design, and the consumer should not be alarmed at this phenomenon.

On-board audio. The LP70+ has a 1-watt speaker on board, the V3-131 has an 0.5 watt speaker, and the LT10 has no audio capability.

Lamp life. For those who plan to use their projector frequently, lamp life is a factor to consider since replacement lamps are usually around $400 retail. The LP70+ holds the competitive edge here with a 3000-hour lamp life. The LT10 is second at 2000 hours. The V3-131 has the shortest lamp life at 1000 hours. However in eco-mode, the V3-131's lumen output can be reduced by 11% in exchange for an extension of lamp life to 1500 hours.

Warranty. NEC and InFocus offer two-year warranties with the price of their products. PLUS offers a standard three-year warranty.

Comments on the InFocus LP70+

The LP70+ is exceptionally strong in data presentation and not so strong in video. Therefore if your presentation material consists of PowerPoint slide shows, text documents, and financial spreadsheets, the InFocus LP70+ is probably the projector of choice among the three in this review. Image quality for this type of material is bright, extremely sharp, and plenty high in actual contrast on the screen. Fan noise is minimal, and the 3,000-hour lamp life contributes to lower cost of ownership. And the unique USB port gives you the option for wired control if you want it. Overall this unit appears to be a superb value for the traveling presenter.

Unfortunately, due to color temperature and contrast limitations, the video and graphics performance of the LP70+ is lacking. Both video and graphics have a greenish cast. Video is very low in color saturation and contrast. Therefore, if the presentation of graphics, photographic material, or video is an important part of your presentation mix, the LP70+ may not be the best choice. Similarly if you want your traveling business projector to double as a home theater video machine, the LP70+ is not the strongest choice for this usage.

Comments on the NEC LT10

The NEC LT10 stands head and shoulders above its competitors in the area of video and graphics display. Color accuracy is much more on the money, and contrast and color saturation are superior. Bottom line, the LT10 is a fine video projector and the other two are not. Therefore, if your presentation material consists primarily of video, photographs, other graphics, or Internet material, you will get the most satisfying performance overall from the LT10. If you want your traveling business projector to double as a home theater video machine, this one is clearly the best choice for that application.

If your mix of presentation material includes data text and spreadsheet material as well as video and/or graphics, there are trade-offs to consider. The LT10 is not as bright as the LP70+, and lamp life is 2000 hours instead of 3000. For text and spreadsheet material we would prefer to use the LP70+, but the LT10 is quite acceptable for this material as well; the difference between the two is not dramatic. On the other hand, the advantage of the LT10 over the LP70+ in video and graphics is dramatic. The choice between the two will ultimately come down to this: if you are willing to give up image brightness in data presentation in order to get better video performance, the LT10 is the right choice.

Comments on the PLUS V3-131

From a performance perspective the V3-131 did not show as well in this comparative review. Yet from a packaging perspective it has a couple of advantages that the other units don't have. At only 1.5" in height it is exceptionally thin. So it may be the best choice for those who need or want to carry a slim briefcase, or those who simply don't like the bulk of a projector that is 2.6" thick. Its wide-angle lens will produce a big image from a short distance. Finally, it has a credit card size remote that can be carried in a shirt pocket, whereas the other two have palm size remotes.

However these advantages appear to be outweighed by the unit's deficiencies: fan noise is excessive, lamp life is low, brightness and video quality were lacking, and there is no zoom lens. Footer adjustments were less user-friendly than on the other two units. Overall, this unit might represent an attractive value proposition if priced substantially below the LP70+ and LT10. But if street prices are comparable it is not a product we would choose over its competitors.

For more detailed specifications and connections, check out our InFocus LP70+ projector page.