Originally Posted by quant2325
The answer is: No, the smartphone is not the new DSLR. Not even close (yet). The Smartphone is now good enough for many people and will improve greatly over the next few years.
1) The dynamic range on the smartphone sensor is not there yet. Worse, there is no way to shoot RAW with most phones. This will soon change.
2) The smartphones use a smaller sensor than DSLRs do. You can cram a zillion MP into a sensor, but a larger sensor certainly helps with IQ.
3) Most of the stuff a DSLR can do like exposure bracketing, super-fast shutter speed, sync. with off camera flash, leading/trailing flash sync, etc. is coming but not there yet.
4) The iPhone 6s is rumored on the photo sites to take over the lead in IQ from Samasung. It is a back and forth battle, with both having advantages.
5) Apple did purchase some tiny firm in Israel that developed DSLR capabilities for smartphones that some photo sites are hopeful we will see in the iPhone 7. This simply shows that the makers of these phones want to see them improve. I imagine everyone upgrades every few years to get this stuff.
For mountain photography, a key is having different primes (or very high quality zooms) along with a DSLR with a sensor that will create sharp enough images for what you are using the photos for and with a wide dynamic range. Shooting in bright sunlight makes using a non-DSLR problematic if it is difficult to see the screen to compose of focus. But to simply take a photo of two of family/friends and the scenery that won't be blown up to a poster size? Smartphones are lightweight and now do the job. Well, good enough for most people. When I took some photos of the kids this winter, it was with a smartphone. The IQ surprised me, and after a little post processing the images look great.
There is no question that a DSLR with several lenses is a heavy, clumsy PITA. It takes time to change lenses, there's a risk you'll drop something critical, and crud gets inside your camera. Most people don't need or want a DSLR, and many who do have them don't need them, either, and don't use them very well. Phone cameras are getting better, they're far more likely to be with you, and for the vast majority of pictures taken, they're fine. For many uses, they're clearly superior to a DSLR.
Further, it must also be recognized that the main display medium used today is an electronic monitor. This device has some profound limits compared to the image files that can be created by modern cameras, including phone cameras. First, compared to most sensors, including phone sensors, it doesn't have very many pixels. It also has a limited dynamic range, many LCD monitors render color inaccurately, and the brightness of most monitors (with some high-end exceptions) varies substantially depending on the viewing angle. In short, if you post on line, you have little control over how your image will be viewed, but the probability is high that the viewing tool will be inaccurate and low quality. Most of the fine points that us DSLR dweebs worry about simply don't matter in this environment.
As quant says, though, a phone ain't no DSLR. This is echoed by a number of others in this thread. In addition to the points raised by quant, I'd also point out that phones (and mirrorless cameras in general) cannot focus on moving subjects with the speed and accuracy of a high-end DSLR, although they work extremely well for things that are holding still. This is a Big Deal, IMHO, and one of the things that makes clean, crisp images of birds (or skiers) in flight possible.
The ability to follow a moving subject is also made easier by an eye-level optical viewfinder that shows you what's happening now, rather than what was happening when the last picture was shot a quarter of a second ago. It may not seem like much, but it makes a big difference.
Nonetheless, technology may be able to solve these problems for phones, possibly fairly soon.
An item which is solely a matter of optics is depth of field. While a shallow depth of field can be difficult to manage and may not render a complete scene in focus, it also allows the photographer to selectively focus on the subject while leaving the rest of the scene out of focus so that the subject stands out from the background. Because of their small sensors, phones will generally have lots of depth of field. This is often OK. Focusing is easy, it doesn't have to be particularly accurate, and most of the scene will appear to be in focus if the image isn't blown up too much.
But if you want to isolate the subject using depth of field, you may not be able to do it with a phone because you have no way to create a shallow depth of field with the small sensor. This may affect how well your composition works. For casual photography, though, it probably doesn't matter.
It should also be noted that, given sufficient time and patience in Photoshop or similar software, you might be able to select your desired subjects, invert the selection to select the background, and add blur to the background. This is often tedious, however, and must be done very carefully, or the result will look obviously manipulated.
Depth of field is purely an optical phenomenon, although digital alteration may be possible as outlined above. Algorithms with improved heuristics may be written to assist with subject selection and addition of artificial blur, but, in general, the only current way to get a shallow depth of field is to use a camera with a larger sensor and a lens with a larger aperture. This sad fact translates into a bigger camera.