The Viewing Experience
Like most projectors in its weight class, the ML550 uses a DLP chip designed to maximize brightness for small projectors. Unfortunately, it also adds apparent scaling artifacts. These are easiest to see as unwanted added patterns in large areas filled with repeating patterns of dots or fine lines. They can also give images a soft focus effect, making small text and fine details in line drawings hard to make out.
Similar artifacts show up with any DLP or LCD projector if you feed it an input signal that doesn't match it's native resolution. With the ML550, however, they show up even if you set your computer to 1280x800, so there's no way to avoid them. The good news is that you may not consider this a serious problem. Unless you use patterned fills in your graphics, you may never notice any artifacts. And if you don't need to show fine detail or small text in data images, you may not mind the soft focus effect either, although you'll likely notice that video and photos lose some crispness as well.
Data image quality. Although the apparent scaling artifacts and soft focus effect make the ML550 a poor choice for showing detailed line drawings or images with patterned fills, the projector did a credible job with the kind of images most people are more likely to use
Color balance was good, with various shades of gray acceptably neutral in most predefined image modes. Colors were suitably eye-catching in most modes as well, although they varied more from one mode to the next than with most projectors. Yellow, for example, was pastel, if not actually pale, in Bright mode; verging on lime green in PC mode; and definitively yellow in Cinema mode. You may want to pick a mode based on which colors you like best.
The ML550 also handled detail well enough for most purposes. White text on black was easily readable at 8 points, for example, and black text on white was easily readable at 9 points, with text breaking up at smaller sizes. Although that limits how much text you can put on screen at once and still be able to read it, it's easily good enough for images like a typical PowerPoint slide.
Video quality. Video is watchable with the ML550, but short of impressive as is typical for this class of projector. Predictably, the soft focus effect that grows from the DLP chip architecture makes the image look more like SD video than 720p HD. There are also issues with color. I settled on Cinema mode as the best choice for color quality overall, but even Cinema mode has some obvious problems. Most colors in most clips were a little washed out, but reds and blues in some clips stood out as oversaturated and shifted to the wrong hue, making them a little too vibrant.
On the plus side, the projector did an excellent job with shadow detail, and it showed only a hint of posterization in scenes that tend to cause that problem. It also handled skin tones well and showed minimal noise.
Other issues. Rainbow artifacts, with light areas breaking up into flashes of red, green, and blue, are less of a problem with the ML550 than with most DLP projectors, but still a potential issue. I saw few enough with data images and with most video that it's unlikely that anyone would be bothered by them. The one exception was a black and white movie clip, where the artifacts showed far more often. If you see these artifacts easily, you may well find them too annoying to watch black and white movies comfortably.
Another minor issue is that the projector's focus changes over about 10 or 15 minutes as it warms up. This can be a particular problem for business use, where you may start the presentation right after turning the projector on, and then have to adjust the focus two or three times, depending on how detailed your images are, before the focus settles into a steady state.