Posted on December 20, 2017 By Nikki Kahl
Acer K138ST Pocket Projector Review – Picture and Sound Quality: Out-of-the-Box Picture Quality, Skin Tones, HDTV and Sports, Audio Quality
The Iron Fist HDTV projected by the Acer K138ST.
The Iron Fist NYC HDTV projected by the Acer K138ST.
A scene from Ender's Game projected by the Acer K138ST.
A scene from Casino Royale projected by the Acer K138ST.
A scene from The Hunger Games projected by the Acer K138ST.
Picture Mode: Bright
Picture Mode: Standard
Picture Mode: Movie
Picture Mode: Picture
Picture Mode: Game
The Acer K138ST has pretty good color, right out of the box, in a couple of modes. Those modes are Picture and Standard. I favor Picture mode because it seems to have the most natural handling of colors, and is comparable to home entertainment projectors I’ve seen in the $1000 range, such as Acer’s very on H7550ST, which I reviewed earlier this year. The first photos I have in the image player above were shot in Picture mode, while the last five images of Katniss in The Hunger Games show the color in each mode, so that you can easily see the difference between them.
The first of that sequence is of Bright mode, and is surprisingly pink on Katniss’ skin. I would never use this mode, personally. One would assume that Bright mode is the brightest mode, and as such, would be strong on greens and yellows. Well, it’s neither the brightest mode, nor does it lean toward that side of the color spectrum. The second picture in the player is of Standard mode, which is actually the projector’s bright mode. The color here is pretty decent, and I would consider it to be one of the Acer’s best modes.
The third photo shows the K138ST’s Movie mode, which is also strong on pinks, but not as much as Bright mode. It’s a little too saturated in the realm of magentas for me, however, so I do not count it as a “best mode.” Some people may like this color correction – I personally do not like the way it looks on skin tones. The fourth photo shows the best mode, Picture. You can see that her skin is a nice beige, the lips, a soft pink, and her eyes are very close to the correct hue of blue. The final mode is Game mode, which is basically a desaturated, less contrasty Picture mode.
The Acer K138ST does a good job on handling skin tones in this scene from Ender's Game.
This scene from Ender's Game is color corrected yellow, and a lot of projector's do not handle this very well - that is not the case with the Acer K138ST.
Another shot that sometimes looks awful on projectors, but looks decent on the K138ST.
This scene from Casino Royale is also color corrected to be a bit yellow, but it looks pretty natural projected by this Acer.
This outdoor scene looks good, though the horse is normally a bit more white than it is here.
This image of Katniss was shot in Movie mode, which isn't as good as Picture mode.
Danny Rand from The Iron Fist looks natural, if a bit pink.
This sports caster looks vibrant when projected by the Acer K138ST.
Reddington's skin looks natural here, whereas it looks a bit pink on the AAXA M5 and M6, as well as some other projectors in this general price range.
As mentioned, in Picture mode, skin tones look pretty great. Everything looks natural and I was most impressed with the color of this mode, particularly its handling of skin tones as compared to the other four modes. In the slider above, I have photos from The Hunger Games, Ender’s Game, Casino Royale, Gotham, The Blacklist, and Iron Fist to show how the Acer K138ST does when presented with various skin tones and color correction. Check out the photos to get an idea of the projector’s color performance.
Overall, I felt that the color in Picture mode is realistic, which is something I appreciate on a projector of this price point. Sure, it’s not as good as say, the $899 Epson Home Cinema 2150 that I recently reviewed, but it is better than both the AAXA M5 and the M6, its direct competitors. The color is one of the major things this Acer has going for it, and though it’s not perfect, it’s pretty good.
The Acer K138ST looks good when projecting HDTV content, such as The Blacklist.
This scene from The Blacklist is a good example of the picture quality in a scene that is both light and dark.
The blacks look pretty dark, even though the projector's black levels are merely okay.
This crime scene in Gotham is a difficult scene for projectors, as it's a really dark scene. The Acer K138ST lacks the dark shadow detail to handle this scene.
This scene from Gotham is also really dark and you can't see a lot of detail, but the skin tone looks true to color (the lighting in the scene is orange on the left side of the frame).
Sports look good in Picture mode.
The reds look pretty good - some DLP projectors make the reds more wine color than pure red. This seems to lean only a little toward wine colored.
The field looks vibrant in Picture mode.
HDTV and sports both look good on the Acer K138ST, though I did have a problem with it. When taking photos of the TV show Gotham, however, I noticed that some of these really dark scenes lack dark shadow detail. As in, I could barely see the outline of Detective Gordon’s suit jacket. Add ambient light to the mix, and I doubt you’d be able to make out much in a dark scene, so that pretty much means no movie or cinematic show watching during the day unless the drapes are closed, and you’ve got good drapes.
I mention this in nearly every review, but I had such an ambient light problem in my living room because of the giant window and horizontal blinds that leaked in between each individual blind. I had to wait until night time to take photos, which did not work for my schedule, and that didn’t last long. I bought blackout curtains from Amazon (I got black curtains, but you can choose other dark colors like navy or purple), and a curtain rod for around $35, and installed them immediately. I am planning on getting the same curtains for my kitchen and bedroom windows, as they’re awesome for blocking out tons of light.
Anyway, if you’ve got typical apartment blinds, you’re probably going to want to invest in either a bright room projector or those curtains. This little pocket projector isn’t bright enough for rooms with more than a modest amount of ambient light, as the light leaking in from the closed kitchen blinds was a bit too much for the Acer K138ST. That said, it’s not going to be a great projector to host a Super Bowl party with, though it will be enjoyable in an environment with good control over the lighting. If you don’t have that, there are plenty of brighter home entertainment projectors in this price range (ViewSonic and Epson have a few).
There are two 3-watt stereo speakers built into the Acer K138ST, and they are capable of producing some pretty decent sound at a loud volume. Definitely loud enough for your home entertainment needs, whether gaming or watching movies indoors, or for a summer movie night outdoors. One of the coolest things about this little pocket projector, besides its portability, is that it is Bluetooth enabled!
That means you can link your Bluetooth speakers to the projector, giving you more flexibility in terms of sound quality. My friends and I have used one of those little Beats by Dre pill-shaped Bluetooth speakers for pool parties, and I would venture to say one of those (or a similar model) would pair quite nicely with the Acer K138ST.
If you’ve read any of my other reviews, you know that I feel strongly about good sound quality, and always suggest hooking your projector up to external speakers. With a short throw pocket projector, that can be a bit of a nuisance if you’ve got a wired setup, as the cords will be draped every which way and create a bit of a mess in the middle of the room. I’m not one for mess, so I find the Bluetooth capability of the K138ST to be a truly awesome feature.
Next up is our Performance page, where I will discuss brightness and input lag for gaming, complete with photos of gameplay!
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