The ALEXA XT has the same size sensor as previous models, but with its increased processing power, it can now record the full sensor area all at once. The ALEXA Plus 4:3, Studio, and M can all record in 4:3 or 16:9 modes; the XT models can do all that, as well as featuring a new Open Gate mode, thus giving the highest possible resolution output from the sensor. This is a great option to have and gives you a lot of flexibility for image repositioning, resizing, rotating, or stabilizing a shot. Plus, its native 3.4K resolution makes for an easy upscale to 4K output.
In Open Gate mode, the ALEXA XT can record ARRIRAW at a resolution of 3414 x 2198 (1.55:1 aspect ratio). Vertically, that’s higher resolution then most 4K cameras today, which come in at 2160 vertical lines. The image can be scaled by only 20% for 4K finish, or 15% for Ultra HD finishing.
Want to see how this looks? You can try it yourself using some sample footage from Arri’s site and the latest version of DaVinci Resolve, which supports the Open Gate material. (Take note that you’ll need an FTP client in order to download the sample footage.) Resolve 11 Lite is free and will now let you output up to Ultra HD (3840×2160) resolution images.
It’s important to remember that because of the wide sensor area, lenses must cover an image circle of 33.5mm. Always be sure to test your lenses, especially wide angle lenses, before using this mode.
The ALEXA XT with Open Gate mode is now available to rent from AbelCine.
If you’re interested in learning how to get even more out of your ALEXA/ALEXA XT, keep your eye out for our next Arri ALEXA workshops on both coasts.