Don’t let the lack of inches fool you, the Optoma ML550 (around £350 ex. VAT) is a highly capable and surprisingly bright LED projector, equipped with the same business-class features as larger Optoma products. Features such as HDMI and VGA connectivity plus integrated memory and both USB and microSD slots for PC-free presentations. It’s even got built-in audio and optional Wi-Fi, making for a very capable as well as highly portable little projector indeed.

A Portable Package


Small enough to fit in one hand (assuming normal-sized hands!), the ML550 weighs in at a mere 380g, making it very easy to carry about. It also comes in a smart padded case along with the external AC adapter and power lead needed to make it work plus a tiny remote control and an I/O cable with VGA and external audio connectors.

The main reason for the lack of size is the use of LED as a light light source which, as well as reducing bulk saves on energy and is also rated to last for 20,000 hours so there’s no bulb to change. Imaging, meanwhile, is handled by the highly regarded DLP chip from Texas Instruments giving the ML550 a native resolution of 1280×800 pixels (WXGA) to handle a varerty of display formats including 720p.

Recommended projection distance is 0.55 – 3.23 metres which isn’t huge, but at 2 metres we displayed images with diagonal measurements of 60-66 inches, depending on format. In our book that makes it more than adequate for presentations to audiences of 10-15 people or, possibly, more.

Another plus is that, with a 500 lumens, rating the results were a lot brighter than we have come to expect for an LED projector, enabling the ML550 to deliver a clear picture with only minimal blackout measures. And if that’s not good enough, the almost identical ML750 (around £450 ex. VAT) bumps the brightness up to 700 lumens.

Maximum power consumption is 65 Watts and despite the LED lighting the ML550 still needs cooling with no fewer than three fans inside the casing. These do make a bit of noise, but not enough to be intrusive and a lot less than on other projectors we’ve tried. You will, though, need to let the projector cool down before moving it, just like projectos with bulbs inside. The usual wind-down foot at the front can also be used to angle the light beam plus there’s a screw fixing to enable the projector to be attached to a tripod or ceiling bracket.

Simple Setup


Putting the ML550 to work is easy, which is always a plus as this can be a real hassle when you’re in a hurry – as you always are when giving presentations on the go. Focusing has to be done manually, which is no problem, and there are a number of push button controls on the top of the projector with built-in LED indicators for use in the dark.

For the most part, however, the ML550 can be setup and operated via the remote control with an intuitive interface that we had no trouble getting to grips with. In fact the only real issue we had was with the location of the IR receiver as it’s tucked away round at the rear of the unit, meaning we couldn’t stand beside or in front of the projector and operate it.

There are four display modes (Cinema, Bright, Photo and PC) and simple controls for keystone correction to get a nice square picture. You can even project 3D movies from the ML550 although you will have to buy 3D active shutter glasses from Optoma in order to watch them.

Host attachment is done using either the VGA lead supplied or via HDMI. More than that, the HDMI interface supports MHL (Mobile High-definition Link) so, in theory you can attach a smartphone or tablet to both mirror the display and charge it at the same time. Not all devices come with MHL, however, and working out if the technology is even available can be hit and miss.

You can also add wireless connectivity in the form of a tiny WU5205 USB dongle, adding around £45 (ex. VAT) to the price.

Presentations To Go


We ran several tests using laptops and by cabling to a DVD player and set-top box, but one of the most impressive features of the ML550 is its ability to be used standalone rather than having to connect a computer or other device to it at all. Instead you can put your content onto a USB memory stick or microSD card or even copy documents onto the 1.5GB of internal memory for the ultimate in mobile use.

To take advantage of this option we selected the source we required from the setup menu, the ML550 then allowing us to choose the documents to be displayed via an on-screen browser using the remote. We found it easy and very convenient, the ML550 coping with just about everything we threw at it thanks to built-in viewers for, not just still images and most video formats, but PDFs and Microsoft Office documents too, including PowerPoint presentations.

On the down side, we did experience a few pauses here and there, especially when loading large documents and scrolling between pages but, overall, we were very impressed with the capabilities in this department. It was also nice to have built-in sound although, at just 1 Watt, the built-in speaker wasn’t that loud.

Portable Powerhouse

Having tried mobile LED Projectors in the past and not been that impressed, we were more than pleasantly surprised by what Optoma has managed to achieve with the ML550. Not only is it tiny and very portable (we’ve got bigger digital cameras!), it also delivers the goods both in terms of brightness and picture clarity. Indeed, it compares well against conventional projectors with higher ratings than the 500 lumens quoted. Add to that extensive options for PC-free presentations, including built in viewers for Office and other popular document formats, and you have a real little projector powerhouse, literally, in the palm of your hand.