There is a lot more going for portable projectors than their small size! If you are deciding whether to buy a portable projector or full size projector, a portable projector is always a good choice if you do not have a dedicated home theater setup, and/or if you plan to be moving the projector around on a regular basis like outdoors in the backyard for watching movies with family and friends.
Another key advantage going for portable projectors is that, as a rule of thumb, they are much easier to setup and use than full size projectors. The Nebula Mars II Pro portable projector certainly offers one of the most convenient user experiences of any portable projector, thanks to neat features such as automatic focus, a feature usually found on full size projectors.
Projectors with automatic focusing are really a joy to use because they do the focusing for you via a rangefinder ultrasonic sensor that measures the projection distance and a small motor that rotates the projector lens just like a human hand would. The ultrasonic sensor and lens motor, essentially, mimic the eyes and hands of the user.
The automatic focus works well in the Nebula Mars II Pro projector, effectively focusing very quickly but, the projector does have to be placed within one meter (minimum distance) and three meters maximum distance from a projected surface for the ultrasonic sensor to be effective. Auto focus itself cannot be disabled but, you can disable AutoFocus correction, which is a built-in feature that helps correct the automatic focus. You can have this feature disabled if, for instance, you plan to hang the Mars II Pro projector from a ceiling, which you can since you can rotate the image 180 degrees from the settings.
The maximum projection size is 150 inches (30 inches minimum projection size). The native projected resolution is high-definition (HD) quality with 16:9 (1280x720) ratio of width to height but, the Mars II Pro projector can upscale to 1920x1080 at 60 frames per second via HDMI. There is also support for multiple user interface languages other than English.

There is automatic and manual keystone correction too, which you can disable and enable so, you can manually adjust the tilting of the projected image horizontally and vertically. There is also quadrilateral keystone correction available, which many projectors don't integrate and really helps getting a perfectly rectangular projected image. The color temperature of the image can also be adjusted but it's limited to only three settings (normal, cool and warm).
The Mars II Pro lens cover is dual purpose. As well as protecting the lens, the cover also integrates smart circuitry that triggers the unit powering off automatically when the projector lens cover is closed during normal operation. When opening the lens cover, the projector automatically powers on.
There is a grab handle over the top of the Mars II Pro projector. The grab handle is made of a leather strap with the word Nebula imprinted on it. The bottom section of the leather strap has a soft, velvet-like fabric material. On top of the Nebula Mars II Pro projector, you will also find four small leds and the user controls, which consist of 9 buttons in total. Five of those buttons are located on a rocker and consist of four navigational buttons and OK button to select settings. The other four buttons are built separately and include a bluetooth button, back button, volume down button and volume up button.
The buttons on the Mars II Pro projector are very responsive with a silent design so, they don't produce any sound when actuated. With that said, you can have the buttons produce an audible clicky sound by enabling this feature from the menu, which cleverly uses the built-in speakers to make a clicky sound every time you press a button.
The backside of the Mars II Pro projector has a back panel etched in with ten exhaust vents and five connectivity ports, which include a DC in port, HDMI 1.4, USB 2.0 and audio out. There is also a reset button contained inside a small pinhole and an IR blaster receiver to enable control via the included IR remote control. Because of the location of the IR receiver, you will need to be positioned behind or alongside the Mars II Pro projector to operate the remote, which offers a convenient alternative to operate the projector if you don't want to press buttons.
The Mars 2 Pro remote control lets you control every function of the projector and features a mouse button to enable a mouse cursor so, you can navigate using the directional pad. There is no air mouse capability in the remote as there aren't any motion sensors integrated that would let you move the mouse cursor by waving the mouse in the air. There is another way to operate the Nebula Mars II Pro projector without using the remote control and that is by downloading the Nebula Connect app to a smartphone. The app lets you control the projector from any location.
In the center of the base of the projector, there is a gold-plated quarter-inch female thread to attach the Nebula Mars II Pro projector to a tripod that can support loads heavier than smartphones because the Nebula Mars II Pro projector does weigh 1.8kg. The dimensions of the Mars 2 Pro are 14cm tall, 12cm wide and 18cm long.
The bottom base of the Nebula Mars II Pro projector has a rubber section that makes the feet of the projector. The vent cut-out that runs along the perimeter of the base of the projector are the intake air vents that allow the projector fan to take in air to cool the projector internally and exhaust the heated air through the exhaust vents. The projector fan itself makes minimal noise (less than 32dB), which is inaudible when watching a movie.
The intake air vents are raised 1-inch off the ground, which is enough height to allow air to find its way into the projector. Definitely make sure not to block either the air intake or exhaust vents while the projector is running because this will obviously cause the projector to heat up and projectors are particularly susceptible to early damage when they over heat. 
In bluetooth mode, the internal 12,500 mAh battery can power the Mars II Pro projector for up to 30 hours, which is pretty long lasting, considering the projector uses bluetooth 4.0, which isn't as power efficient as the latest bluetooth 5.0 version integrated in newer speakers such as the Soundcore Motion Plus.
For a small, medium size room, the Mars II Pro speaker sound system works well, delivering loud volume via stereo speakers capable of 20 watts of power (10W each). The volume output and sound quality is comparable to the Flare Plus speaker but, it is significantly more pronounced because of the larger body, housing the Mars 2 Pro speaker drivers. The speaker drivers deliver clear treble, good bass and clean vocal midrange, and adequate stereo audio separation, considering that the speakers are built-in and they are fairly close to each other. Projectors as a whole carry some compromises and stereo sound separation is one of them since individually self-contained stereo speakers placed at a fair distance from each other will naturally deliver better stereo imaging.
The Chromecast dongle isn't compatible with the Mars II Pro Portable projector but there is OTG function support; hence you can connect a smartphone directly to the projector, using an OTG cable, which is not included. You can mirror most content but, you cannot mirror or screencast copyrighted content; hence you won't be able to stream movies via Hulu and Netflix from a phone.
With that said, not being able to mirror or screencast from a mobile phone isn't really an issue because the Mars 2 Pro integrates Android 7.1.2 operating system, which comes with Netflix and Hulu preloaded. There is 8GB eMMC of storage capacity and 1GB of memory. The Mars II Pro projector pre-loaded apps take 5Gb of space already right out of the box. The Mars II Pro projector works great as an Android box, since it runs the tablet version of Android. It is not the official Android TV OS though, which would allow you to get Netflix in HD and surround sound.
The Mars II Pro internal battery can power the Mars II Pro for up to 2.5 hours of continuous projection. Charging the battery to full capacity takes 3 hours, which is super fast and possible via 19V/3A input charge. An AC adapter, which matches the rated input charge of the Nebula Mars II Pro projector is also included.
Three hours of battery life can be achieved in Battery Image mode, which sets the projector to low brightness. In Standard Image mode, which sets the projector to the maximum 500 ANSI lumens brightness, battery life is up to 2 hours. There is also an Auto Image mode that you can also select that automatically adjusts the brightness and achieves 2.5 hours of battery life. The main difference between Auto and Battery mode is that Auto mode doesn't set the image brightness to the lowest setting like Battery mode does. Auto mode varies the image brightness between the lowest and highest brightness.
You can update the Mars 2 Pro firmware, as well as set auto sleep to 5 minutes, 15 minutes and 30 minutes. The Mars 2 Pro projector consumes less than 60 watts of power while it's working, and less than 1 watt in standby mode. The lamp life of the Mars II Pro projector is 30, 000 hours and integrates a 0.3-inch DLP projector chipset, which is super small (only 8mm).
The Nebula Mars II Pro projector is also Wifi-enabled, supporting both 2.4GHz and 5Ghz radio bands, which means you don't have to connect to a computer via HDMI cable. You can project an image wirelessly, which is super convenient when you want to take the Mars II Pro projector outside to recreate the experience of a drive in cinema. Check out the review of the new Nebula Solar Portable projector and the Nebula Astro projector - the smallest in the line up.