Determining the picture quality of the GP1 is sort of fluid. The picture quality is relative to the type of usage, and content you plan to project. The most important finding to report is that the best results tend to come from using the User mode, with the color temp set to T2 (one of four choices provided). Some, however will prefer one of the cooler settings, with a bit less red, such as T3, my next choice.
The Brightest mode, uses T1, which is definitely too cool (blue) for photos, but provides the most horsepower for business type presentations. I didn't try the GP1 for gaming, but I suspect T1 or T3 will probably work best.
Here are a couple of images to show you what the BenQ GP1 looks like doing business type presentations (User mode).
The GP1 is a little weak here. In most photos I viewed (as well as standard DVD movies (including Lord of the Rings), faces tend to be a bit too red, and further, the reds are dark. Watchable? Definitely! Home theater quality? Sorry, not a chance. Still those of you who don't apply home theater picture quality standards are likely to be pretty happy, considering the product overall, and its flexibility.
Here's a shot of Gandalf from Lord of the Rings, I think it's a very reasonable representation of what I saw on the screen. The image was taken, while projecting about a 62 inch wide image - which is about as large as I could consider acceptable in a darkened room (that's on a white surfaced projection screen).
The GP1 claims a 2000:1 contrast level, which should put its black level performance just a tad lower than entry level home theater projectors. I have to say that it meets that definition. Black levels are nothing great, but, for example, are better than some all in one projectors such as the Epson MovieMates. Not bad at all! Let's say as good as most under $5000 home theater projectors just 4-5 years ago!
If you are using it as a business projector, for, say Powerpoint presentations, or just projecting spreadsheets, email, or whatever else is on your computer screen, the picture quality is actually pretty respectable. True, colors aren't perfect (or particularly close to perfect), but along the lines of many larger single chip DLP business projectors, in that the Joybee GP1 exhibits issues with reds and yellows. Reds tend to come out oversaturated and dark, and yellows, tend to be a bit greenish yellow. (Does that seem familiar to those of you with business DLP projectors?)
Still, the image quality isn't bad at all, and should be fine for typical small room presentations.
The image above was originally taken with a point and shoot camera. This is the GP1 projected, full frame version of the image shown in thumbnail, in the Menus section.
If you aren't overly critical, you should find the GP1 to be very acceptable for viewing your photos, favorite YouTube videos, and whatever other personal type presenting you plan to do.
One more image for consideration. This directly off of the web - a series of photos of a property for sale, so there's a number of different images and challenges within. Please note, the images captured do seem redder than what was on the screen. This seems to be previously noted issue with my dSLR and others, in that they tend to go "over the top" when an individual color is oversaturated):
From a technical standpoint, greens and reds are both oversaturated, and cyan, has way too much green in it.
I was able to get a component video signal into the GP1 from my cable box, and take a quick look at a little HDTV. Picture quality definitely looked better than standard TV or DVD, thanks to the GP1 having higher than standard DVD resolution. Color was just a tad better too, but from a critical standpoint, the much of the extra potential of HDTV is lost by the not overly great color performance.
I even viewed a few minutes of sports from HDTV. Sorry folks, while the GP1 may be able to project a 50 inch diagonal image (or more) in a dark room, don't expect the image on your wall or screen to resemble the picture quality of any decent LCDTV!
Finally, I took a quick video with one of my point and shoot cameras, an old Olympus 740 model. Below is an frame from the video, that I projected on my kitchen wall. Note that there is definitely some ambient light in the room. Let me also say that the movie appeared a little jerky, and not exceptionally clear, but I can lay that at the feet of my camera - now about 7 years old, and with limited movie clip quality, including being only 320x240 resolution. All considered, the GP1 did pretty well: