From the first shot I wasn't impressed. Taken in "intelligent auto" mode, this log lacks clarity at full zoom and the detail is much worse in the edges -- particularly in the bottom left corner. There's a total lack of contrast in the scene and an unpleasant purple colour cast, too. All in all, it's not a good start.
Things didn't get any better later on. The camera struggled to balance the bright sky and darker foreground, and the colours are just plain unpleasant.
Switching to manual mode to utilise the HDR mode (annoyingly, it's not available in auto mode), the camera has lifted the shadows slightly, but it's resulted in a flat, hazy scene with no contrast, and that purple cast is still very much a problem.
There's better exposure, contrast and colour on this shot of a fungus. The central part of the image has plenty of detail but again, the quality drops significantly at the edges.
This flower is much better all round. There's a decent exposure, sharp focus on the petals, and that purple cast, while not gone, is much less noticeable.
The camera has focused well on this bee. Pity the image has such poor contrast.
This scene has an acceptable exposure overall, and when viewing the image at full screen there's sufficient detail to pick out the church spire in the distance. Contrast is again an issue, though, and that purple colour cast is back.
HDR mode here has only succeeded in lowering the contrast even further. Bravo.
My final shot was much better all round, with good exposure, pleasing contrast and much more attractive colours, without the purple tinge. Still, the short story is the Z4 Aqua is not a good camera phone. While you'll be able to take snaps of yourself and your friends suitable for Facebook, you shouldn't opt for it if photography from your phone is critically important.
Sony reckons the 2,400mAh battery will last for two days of regular use, which I feel is a rather ambitious promise. In my own use, I was able to run the battery down from full to empty in 5 hours, with video streaming at max screen brightness. That's quite a demanding test, however -- the screen on any phone is always the most battery-hungry aspect -- so your mileage will vary greatly based on how you use the phone.
It holds its charge well in standby (Sony quotes 779 hours of standby time), so if you tend to use your phone only occasionally through the day to send a few texts or calls, you can probably get closer to that two-day mark. Keeping the screen brightness low will help the most, and try to avoid anything too demanding like gaming or video streaming if you're trying to eke out the power.
The Sony Xperia M4 Aqua has plenty going for it with its sleek design, waterproof body and sufficient serving of power, all topped off with an affordable price. If you've been eyeing up the minimalist aesthetic of the top-end Xperia Z3 but can't stomach the cost, the M4 Aqua is a cheaper way of putting that style in your pocket.
You do have to make some significant compromises, though. The camera is the most disappointing aspect of the phone, delivering images with poor colour, abysmal contrast and unimpressive detail. Sony doesn't help the M4 Aqua's case either by filling it up with pointless bloatware and leaving such a minuscule amount of usable storage that you're forced to pop in an SD card from the word go.
This phone's clear dedication to style over substance means it's fine for everyday essential tasks, and even a spot of light gaming, but if photography is at all important, or you want a simpler, less cluttered interface, you should look elsewhere.