Back in 2009 (only ten years ago as I write this) I had a "fold-up" mobile phone. I bought it to make telephone calls - the obvious reason. Then I found that I could also send text messages and that it had "predictive text" (which almost invariably produced results that were risible). It also had a built in camera.

There is an old photographic saying that "the best camera is the one you have with you". That's true enough, if the alternative is no photo at all and, clearly, the phone makers recognised that and decided to join the pocket camera market.

Now, let's look at two images taken early in 2009 at the local football ground, where a fleet of helicopters was based while being used to control a large bushfire running in a nearby National Park. The local volunteer Rural Fire Brigade, of which I was a member, was called in to act as standby airport firefighters. Thankfully everything went well and I had time to take some photos. I hadn't used my phone for photographs until then and I found the images it took were poor quality, to say the least. The first photo below does not warrant enlarging beyond thumbnail size.
A week later the fire was still burning and I again found myself called in for "airport duty". This time I took our pocket Canon Ixus camera, capable of taking images of 3 megapixels. As seen above, the comparison in results was dramatic. There could be no doubt that the pocket camera was far ahead of the phone.

Fast forward ten years and phones now are "smart phones" with (I read) more computing power than was available to the Apollo moon walking astronauts. Not only that, but their cameras also have developed enormously and the front facing camera of my new one has 13 mp, adjustable aperture (somehow), variable ISO, and the ability to create "faux bokeh" when in "portrait mode".

The new phone and an article on how they are taking so much of the camera market led to me doing a little exercise of photographing a rose in our garden, using the phone and my DSLR fitted with a 50mm lens. I posted the two images together, as seen below, and asked for opinions on which took which. While everyone made the right choice, I think the very fact that the question was even viable tells a story in itself on how far camera phones have advanced. Click on the image to go to the original page and comments.
Now, don't get me wrong - I'm far from interested in giving up my 'real' camera in favour of using a phone though they do indeed produce quite a good result in good conditions. As might be expected, if the ISO is raised, the image becomes both soft and noisy. But, if there's a photo waiting to be taken and the only thing available is a smart phone, then it's reassuring to know there's a good chance of a usable result. I took this final image (clickable) as a test with the phone's "night" setting. It's not great quality but still surprised me - the settings, after I checked, were 0.5 sec, f1.7, and ISO 12,800!
ADDENDUM
If you're interested in how a full frame camera takes this scene, click on the image above and I've added a full frame shot for comparison in the PiPs and comment stream. What intrigues me is that the full frame had a manual f2.8 lens (ie slower than the phone's f1.7), the ISO was the same at 12800, yet the full frame shutter speed was half that of the phone at 0.25 sec, rather than 0.5 sec. Something doesn't quite match up!