The Zenfone 3S Max has a 13 megapixel camera at the back with f2.0 aperture and phase detection autofocus. It can also record videos in 1080p resolution at 30fps. A two-tone dual LED flash has been provided for illumination.
The Camera application on the phone is quite comprehensive, with several modes, including a Manual mode that lets you manually control the shutter speed, white balance, ISO, and focusing. The controls are all well laid out and if you're in the Auto mode the app will also suggest you to switch to an appropriate mode such as HDR or Night depending upon the situation and provide a quick switch at the bottom that you can just tap to switch to that mode instead of digging through the Mode menu.
The image quality is a bit of hit or miss. At first glance the images look fine, with good colors, contrast and decent dynamic range. However, closer examination reveals overly soft images with little fine detail that almost look like their are out of focus. This is due to the noise reduction algorithm that aggressively blurs out the image to stamp out any noise.
The camera app has many modes but the two we ended up using the most were HDR and Low Light. The HDR mode really doesn't do much. You can see from the samples that there is hardly any recovery in the shadowy regions of the image. The Low Light mode works by combining the output of four pixels on the sensor to create one pixel of the image. This helps reduce noise in the image but it does come at the cost of detail.
1080p video quality is decent, with a fair amount of detail and quick focusing but there is no stabilization.