More than 180 million iPhones have been sold since their first release almost 5 years ago. In the last quarter of 2011 more than 37 million were sold. Sales of smartphones in general are skyrocketing, while sales of point-and-shoot cameras have been declining for the last two years. People are asking whether the iPhone 4S camera will replace the point-and-shoot camera? If not now, when? A year? 3 years? 5 years? The answer isn't based solely on the 4S' technical specifications. Rather, without attempting to make a pun, it's in the eye of the beholder.

Let me tell you my bias. My visual discernment is limited. I often can't see the subtle differences that Sally sees when she's working with Photoshop Elements. So I am more than willing to use the iPhone 4 camera, let alone the iPhone 4S camera, for my photos and forego the use of a point-and-shoot camera. I suspect I'm like the average person in this regard.

Since the introduction of the iPhone 4S last October, there have been a slew of articles on the issue, most of which conclude that the iPhone is coming close to replacing point-and-shoot cameras. Many users have concluded that the iPhone is the camera for them. It takes a good picture, it eliminates having to carry another device, it's easy to use, and it's easy to upload pictures to websites like Flickr, Facebook or Picasa. In addition, the iPhone has a huge benefit - it's a camera you have with you almost all the time.

First consider the technical specs for the iPhone 4S:

• 8-megapixel iSight camera (vs. 5-megapixel for the iPhone 4)
  
  
• More sensitive backside illumination sensor
  
  
• 5-element all glass lens
  
  
• Improved LED flash
  
  
• Lens aperture of f/2.4 (which lets in 50% more light than the f/2.8 lens on the iPhone 4)
  
  
• Dual-core A5 processor which reduces the wait before you take a picture
  
  
• Open the Camera app from the Lock screen and press the volume-up button to take a photo
  
  
• On-the-fly editing. Crop, rotate, enhance, and remove red-eye right on iPhone without the help of editing software
  
  
• Full 1080p HD video at 30 frames per second with image stabilization
  
  

If you're not a camera buff, what this means is that the iPhone's camera is coming close to competing with a point-and-shoot camera. Janice Chen at ZDNet thinks that though the smaller-sized sensor means the iPhone can't really compete on a pure image quality, the pre-4S iPhones are already among the most-used cameras on Flickr.

The key to the better picture quality of the 4S is not just the hardware, it's also Apple's image-processing software. Thus, in addition to looking at the hardware specs, you should look at the photo results. That's where the eye of the beholder comes in. Some of us, through training or genetics, can discern slight differences in a photo. The rest of us are more likely to be satisfied with the iPhone camera.

Thus, all that many us need for a camera is an iPhone. At the other end of the spectrum, for the professional or serious photographer, the iPhone doesn't do the job and probably never will. For those in the middle, it may be a tossup. My guess is that the iPhone will be the dominant camera for most uses.

So far I've dealt with the subject from the viewpoint of the camera and the shooter. You should consider the issue from the viewpoint of the viewer's monitor. Monitors can vary greatly in terms of physical size and pixel size (resolution) and there probably has been at least one compression algorithm applied to your image. Consequently, you cannot be sure of how your photo will look on the viewer's monitor. Therefore, when choosing a camera you should examine how the images look on your monitor. Don't worry about the viewer's.

You should run your monitor at its native resolution and zoom it up or down in even increments, 25%, 50%, 100%, 200%, etc. You can generally find the native resolution on the site that has the specs for your particular monitor. This subject is highly technical and I'll cover it in a month or two. You need a basic understanding to get the sharpest images and text on your monitor. For example, on the latest iMac, the native resolution of 21.5" screen is 1920 X 1080; on the 27 inch screen, it's 2560 X 1440. If the text or image is too small, zoom up.150% or 200% is best.

For an excellent discussion of the technology specs on the various iPhone cameras and some competing cameras, as well as many pictures, go to this Ars Technica article. Its conclusion - the iPhone 4S "certainly meets or exceeds the needs of most casual shooters".

Additionally, "In the end, the iPhone 4S offers convenience--light weight, fits in pocket, simple controls--along with competitive, if not excellent, image quality. Unless you need or want full manual control or greater versatility in lens options, the iPhone 4S certainly makes a great photographic tool."

I suspect that for many people Adobe's Photoshop Elements, let alone Photoshop, is too complicated and has too sharp a learning curve for them to consider using such software. Thus, if the point-and-shoot cameras require less correction than an iPhone, the tendency for some would be to use the point-and-shoot camera.

However, there are a number of apps on the iPhone which easily do basic photo editing and a number of them can give you the ability to do a fair amount of sophisticated editing. I refer you to Camera +, Histamatic, and Camera Awesome.

My guess is that if you think the iPhone is 90% as good as a point-and-shoot, however measured, the iPhone becomes your camera of choice in most cases

Ars Technica put it simply: "Making a decision to ditch your camera for a smartphone is always going to be a matter of personal preference and a trade-off between convenience versus quality." I'll add that what is convenience and quality is very much a personal matter.

As for me, I need a mobile phone for business, I prefer a smartphone, I prefer an iPhone 4S over all the other smartphones, I'm very satisfied with the iPhone pictures, and I love not having to also carry a point-and-shoot camera. So my iPhone replaces my old point-and-shoot.

— Mark S. Bazrod, Editor