Settling down at last to check out what the TW420 can do, I very quickly run up against something else that's not exactly ideal: the projector's black level response. This is generally a problem for budget projectors, but the degree of grey clouding over dark scenes and dark parts of otherwise bright scenes is at times pretty depressing.
Take, for instance, the night-time shot across the bay of the two ferries The Joker has rigged with explosives in The Dark Knight. The TW420's lack of black level response makes even picking the outline of the boats out against the water a bit of an eye-strainer - and this is, of course, just one example of countless others during what is, after all, a predominantly dark film.
Obviously the TW420's black level issues aren't as pronounced or distracting if you're watching something predominantly bright and colourful, such as Toy Story. But of course, no self-respecting film fan is going to only watch bright animation, and for almost any other source type the black level issues are something I doubt that you'll ever really grow acceptant of. Especially as they also lead to dark scenes looking a little flat and short of detail.
While examining the TW420's black level response, I should add that I spotted a faint glowing circle over part of the image that I suspect is caused by a speck of dust somewhere in the projector's lens barrel. Obviously it's unlikely that another sample would suffer the same problem, but I mention it because it raises slight concerns about the build quality of the optical engine.
Another negative issue Blu-ray fans should be aware of with theTW420 is the fact that it can't really handle 1080p/24. Pumping this into the projector results in some nasty horizontal tearing, similar to that seen with games on the PS3 or Xbox 360 that don't employ sufficient V-Lock processing. This means you have to ‘make do' with adjusting the Blu-ray output to a less pure1080p/60, or perhaps more logically given the TW420's native resolution, 720p.
One final negative point finds the TW420 running really distractingly noisily when its lamp is set to its ‘high' output. But then to be fair, precious few people reading this review will want to use this setting anyway, since the damage the high brightness setting does to the TW420's already underwhelming black levels is really quite extreme. And with the lamp set to ‘low', the running noise is actually not bad at all, even if you're sat only a metre or two away from the projector.