While I did a lot of testing with each phone while I used them and frankly I was extremely impressed with both phones, especially when taking outside photos. Testing them head to head I tossed my original photos out and went through and took a variety of photos at the same time with both phones. Pardon the portrait layout on the photos, it was easier to use one hand for each phone taking them this way rather than landscape. To start things off here is a photo taken outside on an overcast day. As you can see both photos look exactly the same, both did a great job outside.
LG G3 - Outside
Samsung S5 - Outside
Moving inside I was able to see a little more of a difference between the two. Trying to take a picture of a cat who won’t stop moving using two phones at the same time by the way is damn near impossible. The G3 picture is a little crisper, especially in the background. It also did a better job picking up the light in the room giving a little less shadow.
LG G3 - Inside
Samsung S5 - Inside
Next I took a shot in my office of a nano quadcopter, this shot was in low light but with the lights on the device on to see how they would handle it. I was actually happy with both shots. The S5 was a little softer giving it a nice look and the G3 was a little crisper. They both had the glare from the lights.
LG G3 – Low Light
Samsung S5 – Low Light
Lastly I took the same shot of the nano quadcopter but this time I turned on two of my studio lights. Keep in mind when I use these same lights for photos I also combine them with a speedlight on my DSLR so I wasn’t expecting the shots to match what I get for product shots. In the end the G3 had the same crisp shot like before and the S5 looks blurry in comparison. Using the S5 shots on their own they look great but when you put them next to the G3 there is a noticeable difference. The laser focus on the G3 clearly helps get quick and crisp shots in any light condition.
LG G3 – Lights On
Samsung S5 – Lights On