Acer H7550ST Sharpness
Acer did a good job when it comes to sharpness, with the H7550ST's being decently sharp for the price! As is typical for lower cost projectors, if focused on the center, you will be able to see some softness out by the corners of the screen. You can remedy most of this by focusing so that the sharpest point is a third out from the center, as per Art's recommendation. This truly works, and if you have a Playstation 4, focusing on the username text is usually a good bet. It's possibly I mentioned already that I am a filmmaker - I specialize in camera operation and editing - so sharpness is something I have a real eye for. During the process of this review, I never had any problems with the H7550ST in terms of focus. Movies, TV and video games all looked pretty sharp, though not as sharp as some of the more expensive projectors or some LCD TVs I've seen.
Since the projector is on a table that gets bumped occasionally, I have to reposition it so that the image is straight on the screen. This doesn't happen often, but the lack of lens shift makes this a physical process rather than a digital one. Before I started working with the Acer, I was testing the Sony VLP-VW665ES - a $15,000 projector - on Elite Screen's CineGrey 3D material and got spoiled by the excellent lens shift and automatic focus right from the remote. Projectors of the sub-$1000 category usually do not come with lens shift, so it's really not a big deal. The H7550ST holds its focus very well. That is, it doesn't lose focus after 30 minutes or more of watching. I am able to watch hours of content without noticing anything of the sort. The only time I had trouble with focus is when I physically bump the projector out of position and have to move it back as well as refocus. This has nothing to do with the lens or focus ring, so that's a plus for the Acer.
In the photos in the slider above, you can see the sharpness of a few movie scenes, the menu of the Playstation 4, and font sizes for your reference. Again - pretty sharp for the price. More expensive projectors will have superior optics, so if high-quality cinema is something you're deeply interested in, you may consider spending a little more on your purchase.
H7550ST Image Noise
While there is some mosquito effect present, as with most single chip DLP projectors, there's not much to talk about. These familiar images from earlier in the review show the level of image noise produced by the Acer H7550ST. The mosquito effect typically occurs in the blurry backgrounds of an image. I found it to be most noticeable on lighter scenes, and more specifically, when I was looking for it. Nothing to mention about motion artifacts either. As for 3D, there wasn't any crosstalk that I could detect.