Here's why the drop in resolution between the 12MP/16MP cameras of the Galaxy S7 and S6 doesn't matter
For as long as Android has been around, the many manufacturers that adopted the platform have been at it, throwing everything they have to outdo each other and hopefully win over new fans. In order to differentiate their products and not just be 'yet another Android maker', those same companies have continuously bet on the very best available in hardware. Looking back, it's not hard to imagine where the "more is necessarily better" mentality came from. We've been essentially conditioned to think that way.
So, in a way, for your average Joe an octa-core processor is better than a quad-core one, 4GB of RAM is more desirable than 3GB of RAM, and a 20-megapixel camera beats a 13-megapixel one. Only, that's not at all the case—at least not necessarily. Which is why Samsung's move to a 12-megapixel camera with the Galaxy S7, down from a 16-megapixel unit with the S6, is defendable—at least on paper (and from what we've seen in practice). And while so far we've been highlighting other notable improvements it brings to the table, such as larger sensor and pixel size, along with wider lens, we wanted to address one concern that some folks have: level of detail, or detail depth if you will.
In short, within the next few paragraphs, we'll try and explain why despite the lower resolution, the images you'll be getting from the Galaxy S7 will be of comparably high definition as those from the supposedly superior (in this particular area) sensor of the Galaxy S6, without a corresponding 25% dip in clarity.
The theory behind it all
So what sorcery allows the 12-megapixel unit of the Galaxy S7 to essentially match the 16-megapixel snapper of the Galaxy S6 in terms of detail depth? It's actually exceedingly simple, though you might need a few seconds to wrap your head around it: the S7 has a 4:3 aspect ratio sensor, while the Galaxy S6's is a 16:9 unit. To aid your understanding, we offer you a simplified visual representation of what that means:
In this instance, the outlined blue and red rectangles are representations of the physical form of the two phone's respective camera sensors, and the part that gets illuminated through the lens by light. It's important to note that we haven't taken focal length into account in this example. As you can see, for the most part, the two are overlapped, with the exception of two slices on the top/bottom and left/right sides. And that's exactly the point: those extra 4 megapixels you get with the Galaxy S6 are, for the most part, distributed on the left and right, or horizontally, giving you a wider view of the composition in front of you. They don't mean that you're getting better detail at any point within the overlapping area.
However, the Galaxy S6 does have a longer focal length of 28mm versus 26mm for the Galaxy S7 (35mm equivalents). In practice, this means that if you're shooting from the same spot, the subject will appear more zoomed in on the S6 than on the S7, and you'll see a slight advantage in detail. If you correct for this, however, by taking a small step forward with the S7 in order to even the playing field, you'll see that there's no notable loss in detail with the new 12MP unit—and certainly not a corresponding one given the sizable drop in resolution.
Jump into the gallery below, where we've sliced a number of stills taken with both the Galaxy S7 and S6, under identical conditions. As you'll quickly find out, there's no notable loss of detail despite the lower resolution camera of the new flagship. For the most part, you're simply getting 4 megapixels worth of information on in width with the Galaxy S6.