[Nexus 6  General] cb474:
I'm not into phablets, so I don't know much about the Note 4. It looks like it has a Sony IMX240 sesnor, with a 1/2.6 sensor, so slightly smaller than the 1/2.5 sensor in the S5. It does have OIS though, which should help with longer exposures in low light. The S5 has an "Isocell" sensor, which is supposed to have barriers between pixels that helps improve color accuracy and sharpness (see: http://connect.dpreview.com/post/0315472077/samsung-explains-the-galaxy-s5-isocell-sensor). I know the S5 has atypically good color accuracy for a phone, though part of that is a choice on Samsungs part not to favor in the post-processing the oversaturated colors that many people like (i.e. that many people mistake for better photos--people often find more accurate colors to look washed out). Anyway, since Samsung usually does a good job in their flagships, I would not be surprised if the Note 4 is comparable or slightly better than the S5. But it's going to be minor differences, I think.

Yes, the new Nexus phone and the 2nd Gen. Moto X are the two phones I'm looking at to replace my Nexus 4, so I've been hanging around both forums. For the moment I'm just trying to get over my raging disappointment that the Nexus 6 really is a huge 6" phablet. Sigh. It does have some nice upgrades over the 2nd Gen. Moto X, I think. (Though if it lacks the four microphone noise cancellation in the Moto X, that's a deal killer for me--I haven't been able to confirm anything about this yet.)

I wouldn't worry about the different sensors in the phones much. They're both fine and more or less in the same ballpark of quality, as 1/3 sensors. OIS on the Nexus 6 is nice and should help with low light photography (and video), that's the biggest difference, depending how important that is to you. In good light, I doubt you'd see much difference between the cameras. For just general snapshots of friends and things like that, I think all these phones are fine.

As I said above, I think people make way too big a deal of the differences between cameras in current flagships. Handset makers try to make a big deal out of small differences, for the sake of competition, because they can't acknowledge the truth that they've all just decided the eight year old technology of 1/3 sensors is good enough and they'd rather make super thin phones. If you're the sort of person who's really going to get into the small differences between one flagship with a 1/3 sensor and another, then you're probably the sort of person that would appreciate an S5 more, because of it's 1/2.5 sensor, and you're probably the sort of person will to take the Windows Phone plunge so you can get the truly amazing Nokia 1020 with it's 1/1.5 sensor and many other advantages (mechanical shutter, OIS, Xenon flash, pixel binning for over sampling, lossless digital zooming).

The LG G3 has the same IMX135 sensor as the 2nd Gen Moto X, but also has OIS. It's prefectly good, but still yet another 1/3 sensor. It's the same sensor in the LG G2, the Note 3, the Galaxy S4, and a bazillion other phones, so it shouldn't be meaningfully different from any of them, except for the potential low light advantage of OIS. (Check this out to see just how many phones have Sony sensors in them: https://en.wikipedia.org/wiki/Exmor).

That being said OIS is not a miracle cure for smaller sensors. Neither is the f2.0 aperature on the Nexus 6. They're nice features, but you can only do so much with a smaller 1/3 sensor. Again, these are all ways manufacturers are trying to fiddle around to make the best out of mediocre sensors. The S5 and even the five year old Nokia N86 with 1/2.5 sensors will do almost as well in low light as a phone with OIS (I think the f2.0 will make less of a difference than OIS). And, again, the huge 1/1.8, 1/1.5, 1/1.2 sensors in the Nokia N8, 1020, and 808 (respectively) are going to way out perform a 1/3 sensor with OIS in low light (as well as in every other situation)--and of course the 1020 also has OIS, on top of a huge sensor.

At this point, I don't really know why all flaghips don't have OIS. It has some benefits. And it's stupid to have to choose between a mediocre 1/3 sensor with OIS and a larger 1/2.5 sensor without OIS. It's like two different choices of how to shoot yourself in the foot.

All that to say, I still think these are all pretty minor differences between phones with more or less similar image making capabilities. I wouldn't choose between the LG G3, Moto X, or Nexus 6 for the camera. I might (might) choose the S5 for the camera, but I hate Samsung phones, so I really wouldn't ever get an S5. If the camera really was the main issue to me, I'd get a Nokia 1020 and enter the wonderful world of Windows Phone (which I think is under rated as an interface anyway). But that's really for the serious photographers.

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A final word to the wise. Take the reviews of phone cameras you see online with a huge grain of salt. There are very few sites that do a good job and know what they are talking about. Most site reviewers are essentially amature photographers, making incredibly subjective judgments about images, with no real knowledge of how to take photos in a way that allow for good comparisons, and overplay the differences between today's phones (since they get the phones for free to review, they also have huge conflicts of interest and will mostly avoid saying anything too negative--like acknowledging that the differences between these phones a relatively minor). Dpreview.com is probably the best site I know of.