Megapixel Truth - What Camera Manufacturers May Not Want You To Know

Are all pixels created equal?

How many megapixels are necessary? That is the question.

In this report you will discover the Truth About Megapixels. You will see how camera manufacturers are allowing the "lack of knowledge" to cause their buyers to fall prey to the megapixel frenzy that has taken the camera buying public captive.

It's not that the manufacturers are deliberately trying to deceive, but they are ALLOWING this "un-truth about megapixels" mania to continue to grow. Obviously, it helps their sales. That is not to say that cameras are not getting better. They truly are.

It has not been very long since the advent of the digital camera that could be purchased by the general public. The first digital cameras were extremely expensive. But, now, digital cameras are as common as cell phones. In fact most cell phones have a digital camera.

Do you remember your first digital camera? Was it a 10-megapixel model? I bet not. More than likely it was 3-megapixels or less, right?

Here is the truth about 3-megapixels: you can print a totally acceptable 5" by 7" photo from a 3-megapixel image. You can even print an 8” by 10” print if you use a resolution of 180 ppi, which would be pretty much unnoticed by most casual viewers.

If you are posting pictures on Facebook, you are using LESS than 1-megapixel of image size. And a single 4" by 6" photo printed at 300 ppi takes a digital image of only 2.1-megapixels.

How Big Can You Print

Here is a chart that shows print sizes at various print resolutions. Keep in mind that a print at 150 dpi is probably not going to look bad at all, but your eyes may pick up "pixel details", and the image may look a bit "fuzzy".

Camera manufacturers are producing cameras now that almost all have image sensors of 8-megapixels and more. From these images, you can make prints as large as you would want, even up to 30” wide. Why? Because when you look at a print that large, you will be much farther away from the picture. Therefore, you will not see the individual pixels.

What is Resolution?

As it relates to pixels, resolution is the number of pixels horizontally and vertically. A 3-megapixel image sensor records about 2000 pixels wide by about 1500 pixels vertically. When you multiply those numbers, you get 3 million. Hence, 3-megapixels. If you double those numbers to 4000 pixels wide by 3000 pixels high, you will have a 12-megapixel image sensor. That does not make a whole lot of sense unless you are a mathematician, but doubling the width and height gives you four times the number of pixels.

What about the screen resolution of your computer monitor? Many monitors are set to display 1068 pixels wide by 768 pixels high. That means that you could not view a 3-megapixel image on that monitor without scrolling from side to side and vertically.

Here is an example of pixels

The actual image is 550 pixels wide. On a computer screen, this looks fine, but if you were to print this image at full size, you would see the little square pixels as shown in the box. The reason is that you don't need a very high resolution picture to display on a computer screen. Your computer shows images at about 72-96 pixels per inch.

You don't need a high pixel per inch resolution when viewing photos on a computer. Notice how much I had to zoom in to show the pixels in this image.

When a photo is printed, the pixels show up to the human eye much better, so you need to print at a higher resolution than the 72 ppi of a computer screen.

What is an Image Sensor?

There have already been a few references to image sensor.

An image sensor is the object that receives the picture. The camera shutter opens to let in light and the light falls on the image sensor to record the photograph. The sensor has tiny receptors that capture the light. The resulting output of these receptors is in what we call pixels. Each receptor is essentially a pixel.

Image sensors are not all created equal. A 10-megapixel image sensor from a Panasonic Lumix DMC ZS3 is vastly different than a 10-megapixel image sensor in a Canon EOS-1D Mark III. So is the price, by the way. (The difference in price is more than $3000.) The Panasonic Lumix DMC ZS3 is a point and shoot camera with a physically much smaller image sensor. The size of the Panasonic image sensor is about 6mm by 4.5mm. This is in comparison to the full frame image sensor, which is 36mm by 24mm.

Image Sensor Comparison

There are several varieties of image sensors. Basically, the larger the image sensor, the higher the price. This is a general statement, of course.

Notice the illustration on the left. The gray rectangle represents a "full frame" image sensor like the one in a Canon EOS 5D Mark II. It is a full frame because there is no "cropping" of image information.

The yellow rectangle represents an image sensor that has the designation of APS-C. These are common in cameras such as the Canon Rebel series and the Nikon D5000.

Finally the red rectangle represents a typical point and shoot camera, such as the Panasonic camera mentioned above.

If each of these sensors was capable of holding the exact same number of pixels, which one would you suspect as having the best quality? If you guessed the biggest one, you would be absolutely correct.

Jamming pixels into a tiny image sensor has gotten technologically much better in the past few years, but there is no doubt that the larger the sensor is physically, the better the opportunity to get a higher quality pixel.

There are many factors that go into the camera that affect the price. However, you can see that there are major differences in the size of the image sensor, and, therefore, major differences in the size of the tiny receptors (or pixels) that record the pictures.

Smaller sensors have more issues with image quality, especially with digital noise. The result is that you can conceivably have a 6-megapixel camera that produces better image quality than an 8-megapixel camera with exactly the same sized image sensor.

It’s complicated, but, fortunately there are camera geeks who love to investigate these things and let us know what they found out.

Back to the camera issue, and what size image sensor do you need.

The truth is that you do not have to upgrade to a newer camera based on the number of pixels in the image sensor. There are other factors that should be considered more important than the megapixel count.

"What should you base your camera buying decision on?" - you might ask.

Glad you asked.

Here are a few considerations:

1. Image quality. There is a difference, you know, even among equal categories of image sensors. Each manufacturer creates a different computer chip for their camera that processes the pixels for the image output. And, not every pixel is identical.
   
   There are major differences from image sensor to image sensor and especially from camera type to camera type. For instance, a "point and shoot camera" and a "full-sensor DSLR camera" are as different as weeds and roses (see the discussion above).
   
   To find ratings for the image quality of a particular camera, you will need to do some research, looking at review sites that rate such things. There are two that I highly recommend: www.imaging-resources.com and www.dpreview.com
2. Feature set. Cameras are getting more hi-tech with each release. Look for the features that are important to you. Consider the kind of photos you will be taking before you buy. Cameras are not all created equal, and not every camera is equally suited to all tasks. That is why the same manufacturer might release 4 different models at the same time. Again, it is important to check the camera review sites before making you decision.
3. Point and Shoot or DSLR. How passionate are you about your photography? It may be time to raise the photographic bar in your life. In spite of the increased cost, a DSLR camera will open up a whole new world of image-producing options for you.

Bottom line:

Don't base your decision on the number of megapixels in a camera model.

And, PLEASE, don't make your decision when you are standing at the camera counter of a department store.

Buy your camera after you have done your research.

Since there are so many models on the market, you could spend an extraordinary amount of time doing this research. If you have a general idea of the kind of camera you want and the capabilities you require in a digital camera, then you can rely on the research on this website.

It is why the website exists.

Check out the list of camera categories in the menu on the left. It just makes sense to find someone you can trust and use their advice if you are not totally knowledgeable yourself.

As always, Happy Shooting!