Vivitek Qumi Pocket Projector Page 2
Though not designed for real home theater duties, I felt it was worth running the Qumi though our normal testing procedures. That way, you have an idea where it stands compared to the big dogs.
On a 100-inch, 1.0-gain 16x9 screen, the Qumi produces about 3.5 ftL. Not a lot, certainly, but amusingly not much different from what you get in a movie theater (though that image is much larger). With a black 0-IRE image, the Qumi produces 0.006 ftL. Not bad, really, and better than most LCD TVs. The contrast ratio is around 580:1. Also not great, but still a very watchable image. There's an Eco mode that quiets the internal fan a little, but drops the light output by about half. Way dim, and not recommended.
A 100-inch screen is bigger than is likely intended for the Qumi. If you shrink the image to about 60-inches diagonal, you're getting around 10 ftL which is pretty reasonable.
The color points, though, are really oversaturated. Red and green are way off the charts, and even blue is a bit off. The resulting image doesn't appear quite as cartoony as the numbers suggest, but it's definitely more vibrant than is strictly accurate.
In the Warm color temp mode, the Qumi tracks really well across the grayscale range, right around 7200 kelvin. So even though it's 700 kelvin off D6500, it's never more than 75 kelvin off its own average. That's better than many big projectors.
The only major issues are an extremely noisy low end (dark images), uniformity and a gamma issue where it clips bright images. So with dark scenes, there's lots of noise, and with bright scenes, there's little to no white detail (white crush). The left side of the screen is bluer than middle-right, but then is blueish again on far right. It's a like an island of warm image in the off-right center. Not that noticeable away from test patterns, though.
There are some chromatic aberrations due to the small, inexpensive lens, but that's to be expected, and with regular video it's not that noticeable.
Processing wise, the Qumi isn't great. There's no 3:2 pulldown detection, so film based content is going to have jaggies. This is only an issue if you're using a source that doesn't output progressive video (480p/720p/1080p) on its own.
With the rotating bar test from Spears & Munsil Benchmark Blu-ray, there are only small jaggies in the bar, but the ring flashes, indicating incorrect deinterlacing. The 1080i Ship clip on this disc had noticeable, but not severe, jaggies on the rigging. The 480i Bridge clip looked quite good, actually, with minimal jaggies on the cables. The rotating bar from the HQV Benchmark DVD looked decent, with jaggies only visible starting around 15 degrees. The Flag clip on this disc had some small but noticeable jaggies on the flag, and little detail in the bricks behind.
Scaling-wise, the Qumi does a job, but not specifically a good job. The image with SD content is very soft. Yet if you give it a detailed image like Blu-ray (or a decently scaled DVD image), it's actually quite sharp. Enough so that you don't really notice it's "only" 720p.
The question I have after testing the processing power of this cheap and chipper pocket projector, is how inexcusable any processing errors are these days. If Vivitek can make an entire projector for $500 that still performs reasonably well (C maybe C+ to be fair) on video processing tests, companies making more expensive products have no excuse for them not to perform perfectly.
Though there's a lot of negativity in this review, I actually like the Qumi a lot. For what it is, it's really cool. When watching video, either DVD or Blu-ray, the image is far more watchable than the numbers and tests suggest. This is largely because, for $500, I wasn't expecting much from something the size of my hand. Would it work for as a main home theater projector? No, I don't think so. But as a travel projector, or to project an image anywhere you want one, it's really cool.
I'm not sure what the problem is for which this projector supplies the solution, but if you can think of one, the Qumi works pretty well.