[Xperia Z5 Q&A, Help & Troubleshooting] TheWarKeeper:
Please do not listen to the typical the galaxy s6 has a better camera talk because this simply is not true!

I have owned both and i will tell you right now why the Xperia Z5 is the better phone for you.

1) Camera Resolution, Xperia Z5 can take 20.7mp pictures in 16:9 mode, Galaxy S6 can only take 15.9mp pictures in 16:9 mode

2.A)Camera Quality, Xperia Z5 takes photos with incredible color fidelity and much sharper photos, by comparison the galaxy s6 photos look a bit blurry

2.B) With Xperia Z5 you get the same camera experience as all other costumers that bought the Xperia Z5, with Galaxy S6 you are in a lottery to get a worse or a better camera, Some Galaxy S6 has IsoCell Camera Sensor which is the Old Gen Galaxy S5 Camera Sensor or if youre lucky you get the Sony IMX 240 Camera Sensor, both are good, but sony_imx_240 is better.

2.C) Has dedicated camera button allowing you to focus and take the picture.

2.D) Oh and i forgot something very important, Camera API 2 in galaxy s6 is very buggy even with android 5.1.1, Its so buggy infact that it is currently useless and unusuable.

3) Sony Xperia Z5 may have a cpu that is a bit weaker, but its noway "much" slower as people think, the phone does not suffer from overheating because Sony installed a special cooling system to keep the phone cool all the times, therefor throttling in general scenario cases (gaming, playing videos, etc...) does not occur in this phone.

4)The Xperia Z5 has a GPU that is a bit more powerfull than the Galaxy S6, it also supports special directX11 instructions set that the Galaxy S6 doesnt, for example Xperia Z5 can process hardware tesselation (yes by that i mean the thing you find in games like Grid or Colin Mcrae Dirt 2,3 etc...)

5)With the Xperia Z5 you have Radio, with Galaxy S6 you dont

6)With Xperia Z5 you have SD Card Support up to 200GB, Galaxy S6 has no SD Card Support.

7) Xperia Z5 has a better battery than Galaxy S6 (Galaxy S6 battery is only 2550mah)

8)With Galaxy S6 screen quality you are in a lottery to get a bad screen (screen with pink tint on it) and probably not all stores will allow you to return your phone because of the pink tint, Samsung will not swap it either because they consider it "normal" when it clearly isnt.

9) If you have a defective lens and you need to send it to samsung for repairs, Samsung may ignore your defective lens and pretend its normal and within "quality standards", which is not the case as some users complained in the galaxy s6 section of this forum.

Pros of Galaxy S6

1)You get a Remote Controled IR blaster which will allow you to control your TV, DVD and PowerBox.

2)You get an amazing OLED Screen instead of an LCD IPS Screen by Xperia Z5, there are drawbacks to oled screen, for example the OLED Screen can produce the best contrast ratio you can possibly think of, but the 2560*1440 resolution is not an RGB Matrix, its an interpolated color matrix, so the resolution is actually lower than the 2560*1440, if you are not carefull and you leave your phone screen on for a long time showing the same picture over and over again you can burn the screen and youll end up with shadow pixels that are no longer there, theres no way to fix this issue as its a natural degradation issue caused by CRT and OLEDs, LCD do not have this issue, still, overall the image quality of an OLED screen is unrivaled by any LCD screen no matter how much it costs, no matter who makes it, LCD screens are limited by their own technology when it comes to color fidelity, pixel response time and contrast ratio, things that OLED surpass by an unmeasurable margin Example: a good LCD screen has a contrast ratio of 1250:1, an OLED screen has unmeasurable contrast ratio (Over 1.000.000:1), an LCD screen (TFT screen which is worse image quality than an IPS screen) has around 2ms response time, a proper OLED screen has 0.01ms response time, resulting in less blurriness when playing fps games where camera moves alot.

3)You can set a lower screen resolution for any game you want to increase fps performance of said game, Xperia Z5 does not have this ability, altough the 1080p beying a lower resolution is a more or less good balance so it only needs said ability for like 2 or 3 games

4)You have heart rate sensor, oxigen blood level sensor and walking footstep sensor, frankly i dont use them much but they are an addition and a great bonus to some.

5)Galaxy S6 has a very good post processing resulting in little noise across the entire picture, but this makes all photos loose sharpness, something that the Xperia Z5 avoids by ignoring luminance noise and only post processing the chroma noise, so its a subjective taste, no camera is better than the other as galaxy s6 has its strengths and weakness and xperia z5 camera has its strengths and weakness.

6)Has OIS which works decently enough, altough in video mode Xperia Z5 has a much better video stabilization than Galaxy S6, Xperia Z5 has no OIS, so photos will have to be taken with a more steady hand.

So if you really want an impressive camera, i would go for the Xperia Z5, Galaxy S6 has an excelent camera but it doesnt really stand out as innovative or simply awesome with nothing to match it, LG G4 is a very good competitor (camera wise) to the Galaxy S6, Xperia Z5 camera is unique, its Wide angle lens is excelent and no other phone comes close to it because of its unique specifications, ill tell you right now im more impressed with the Xperia Z5 camera than with the Galaxy S6 camera.