Acer's compact, portable full HD projector runs on its built-in battery for a while without external power when needed. However, it is not suitable for larger images or movie use.
Text: Teppo Hirvikunnas
Photos: Teppo Hirvikunnas and the device manufacturers
The Acer C250i is a small, easy-to-move full HD projector that can also run on battery power. Its built-in battery promises up to five hours of viewing time without a cord. The projector is also designed specifically for this purpose. It can be easily mounted in different positions, such as vertical or horizontal. However, in vertical mode, the image is only visible when the projector is mounted upright or horizontally. This is intended primarily for mirroring the phone’s display on a projector. The side and bottom of the device have threaded mounting brackets for a camera stand (triangle bracket). The projector is therefore easy to place almost anywhere.
The projector’s throw ratio is fixed at 1.2, meaning there is no adjustment for the image size; it is determined by the distance from the projector to the screen. For example, for a 80-inch image (width 177 centimeters), a distance of about 213 centimeters is required. The lens offset of the device is 100 percent, meaning the lower edge of the image is at the same level as the lens. It is possible to raise the image by tilting the projector, and Acer’s wide trapazoid adjustment controls make it easier to position the projector. The projector is also able to automatically straighten the image to a vertical perspective, and there is also adjustment for horizontal orientation (±15° adjustment). Adjustment is also possible at an angle. There is a small adjustment wheel next to the lens for focusing. Its operation is too fast, and focusing on the image is somewhat difficult to feel.
The connections only include one HDMI input, which is sufficient in itself. The Acer C250i also comes with a wifi dongle, which has an inconspicuous slot on the projector’s top. This projector should be able to connect wirelessly to a phone, even if it’s just using the phone’s display as a mirror. Unfortunately, using the mirroring function on the phone’s screen was difficult. The Sony Xperia needed to be connected to the Acer EZCast app, which was also difficult to get working. According to the projector’s display, connecting the phone to the HDMI input was easy on Samsung, Huawei, and Oppo phones, but it was equally difficult with Samsung. Basically, the phone can be connected to the projector’s HDMI input via the phone’s USB-C port, but Acer does not support the mhl functionality that makes this possible. This can be circumvented with a suitable adapter, though.
In this and many other cases, a proper user manual would have been needed. Acer only provides a quick guide, but not in Finnish. Furthermore, there are no proper user manuals that explain all the functions of the device! This is a clear deficiency.
The biggest disadvantage compared to competitors is that the device does not have a built-in media player or the generalized Android TV application platform. Many streaming services would be directly integrated into the device in this way. This shortcoming is, of course, easily fixable in principle with a SmartTV stick that connects to an HDMI port, costing only 40–50 euros, or a similar add-on. In this device, the feature would indeed be built-in. It would also make use easier.
The projector has a built-in, sound-wise modest speaker, but you can still get sound out of the 3.5mm output as well. The device has a Bluetooth receiver, so it can also function as a Bluetooth speaker when needed. The sound quality, however, isn’t quite on par, and it’s hard to come up with any useful use for it in this context.
Setting up the Acer was actually easy (except for mirroring the phone screen). However, using it is not quite as smooth. The remote control receiver is located in front of the device (on the same side as the lens), and the remote control’s operation is also sometimes erratic and glitchy. This makes adjusting the picture difficult, for example, during setup.
The picture quality itself is decent: the colors are naturally reproduced directly from the package, and the image is also reasonably sharp, if you can just sharpen it up properly. For some reason, however, the pixels seemed to stand out more when viewed up close than, for example, on an Epson with 600-euro full hd resolution.
Acer reports a modest 300 lumens in light output, and even in a slightly brighter setting the output is simply not enough. Especially if the image size is even 60 inches. In a completely darkened room, the 80-inch image will struggle if you use even slightly higher gain (>1.3) cloth. But then the black contrast also becomes weaker if there is even a hint of ambient light in the room.
The image has versatile settings, but they don't allow for any increase in brightness, and anyway, all kinds of gamma adjustments and levels of partial colors are completely unnecessary in this type of projector.
With the battery, Acer could only operate at normal brightness for about 1.5 hours. This is enough for a short film with a few kids. With the lamp’s eco mode, the battery might last almost five hours, but its light output is practically only sufficient for a 30-inch image in a dark tent.
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