Rather than focussing on a single device, Sony decided to launch three different variants of their 2015 flagship phone, the Xperia Z5. Other than the actual Z5, one was a Z5 Compact (the same phone but smaller in size), and the other, the Z5 Premium, which was probably the eye-catcher in all three devices. Why? Let's see for ourselves.
When looking at the Z5 Premium from the outside, the first thing to notice is the size of the device. The Z5 Premium is a bit larger and thicker than the actual Z5, having a screen size of 5.5 inches (as opposed to the 5.2 inches one on the Z5). it also has a more reflective (glass like) back (as compared to the matte/frosted back on the Z5). However, the most highlighted difference in this variant is its display resolution. The 5.5 inch screen on the Z5 Premium packs a resolution of 2160 x 3840 pixels (at a pixel density of 806 pixels per inch). Yes, a 4K display screen. That is indeed something unusually new in the whole flagship game.
First possible thought when it comes to what's powering the device: Double the resolution, double the power, right? Sadly, the answer is No. The Z5 Premium has the same specifications (as found in the Z5) in terms of performance. It's powered by a Qualcomm Snapdragon 810 chipset with an eight-core (Cortex-A53 + Cortex-A57) processor, alongside an Adreno 430 GPU. So technically, it may affect the performance of the device (on paper, at least), but would be almost negligible. The phone also has the same amount of internal storage (32 GB) and 3 gigs of RAM as well as a microSD card slot for storage expansion up to 200 GB.
At the back, the Z5 Premium houses a 23 megapixel camera at an aperture of f/2.0 and an LED flash. It also records videos in 4K (at 30 frames per second) as well as in slow-motion 720p (at 120 fps). The front-facing camera is a 5.1 MP sensor with an aperture of f/2.4, which is probably good enough for your daily needs.
It's quite a relief to know that the Z5 Premium does not pack the same battery as the one found in the Z5. In this variant, the battery is a 3430 mAh one, which is big enough to last the phone for a day's use on an average basis. So if you're in for the gimmicks: a larger screen, 4K display, shiny back and a bigger battery, then the Xperia Z5 Premium may be the 2015 flagship to fit right inside your pocket!