The way a digital camera works is that it processes light and color information through its lens and then records this information onto a removable media card. The information stored to this media card consists of digital data that is ultimately represented in digital pixels.

A 2 Megapixel (MP) camera can process and record images that consist of 2 million pixels apiece. Similarly, a 5 Megapixel (MP) camera can process and record images that consist of 5 million pixels apiece. Why is this important?

Two reasons. First, the more pixels that can be recorded to an image, the larger the image can be printed. And second, the more pixels an image contains, the more detail will be revealed of the subject matter.

The image above is a composite of two photographs taken by two different digital cameras, a 5 Megapixel camera and 2 Megapixel camera. For comparative purposes, we've magnified these images to be of equal scale. Notice how the difference in detail is very obvious. (Note: if you have a 3 or 4 Megapixel camera your resolution capabilities will fall somewhere in between these examples.)

In addition to the differences between cameras, there are also settings you can make within each camera to render its optimal resolution (image size and quality). The first part of this lesson focuses on the difference of resolution between a 5-megapixel camera and a 2-megapixel camera, and walks through the process of taking an outdoor portrait. The second part focuses on downloading images to your computer, and preparing it for the highest quality print resolution possible.

Basically, there are 2 variables that determine the resolution of an image: camera megapixel size (2 MP, 3 MP, 4 MP, 5 MP, etc.) and the resolution settings (pixel dimensions/compression level). First, we will take a look at the resolution settings of a 5-megapixel camera.

RESOLUTION
ADJUSTING THE IMAGE QUALITY AND THE IMAGE SIZE

Most digital cameras offer a variety of resolution settings that ascend in both image size and quality. Typically, they are:

Standard Quality -
A JPEG setting ideal for web quality images, the only mode in which the number of pixels and the level of compression can be adjusted.
High Quality -
A JPEG setting good for web and some print quality images. This setting offers the maximum pixel count with medium compression.
Super High Quality -
The least compressed JPEG format, great for both web and print, write time to card is faster than in TIFF or RAW formats. This setting offers the maximum pixel count with a minimum of compression.
TIFF (Tagged Image File Format) -
This format is designed expressly for print, applies no compression, but images take more time to write to card and file sizes can be quite large.
RAW -
Because there is no compression applied to an image in this format, image quality is optimal and sometimes noticeably better than with the TIFF format. The write time to the card is slightly faster and file size is somewhat smaller than with the TIFF format, but typically files can only be displayed as images with the camera software or in recent versions of Adobe Photoshop.

Some cameras also offer a mode that allows you to shoot in both JPEG and RAW quality settings as well.

The chart below illustrates the overall differences between these modes.

Figure 1

The next chart illustrates the approximate number of images you can expect to record to a 32MB CompactFlash card with a 5-megapixel camera at various resolution modes.

Figure 2

If you prefer to shoot in the TIFF or high quality JPEG modes, we recommend purchasing larger media cards, as you will only be able to record a few images to an empty 32MB card (roughly 2 for the optimal TIFF setting and 8 for the high quality JPEG setting).

Check your owners manual to see how to modify the resolution setting (figures 3 & 4).

COMPARISONS
To give you an idea of the size differences between resolution settings in a 2-megapixel camera, we photographed an apple at the optimal JPEG settings and placed the results next to each other. Then we did the same series of shots with a 2-megapixel camera and placed the results next to each other.

As you can see with the 2-megapixel camera, the super high quality JPEG version is roughly 3 times the size of the high quality version and 9 times the size of the standard quality version (figure 5). With the 5-megapixel camera, however, the super high quality JPEG version is roughly four times the size of the high quality version and 16 times the size of the standard quality version (figure 6).

Notice how the 5-megapixel result of the apple is almost 4 times larger than that of the 2-megapixel result. This illustrates the basic difference between the two cameras.

SHOOTING FOR HIGH QUALITY PRINTS
For this next part of the lesson, we decided to shoot an outside portrait with the 5-megapixel camera to illustrate how your resolution settings will affect your print sizes.

First we set the resolution to its lowest setting (standard quality JPEG) and adjusted the White Balance for daylight. To learn more about White Balance settings, check out the White Balance lesson on this site.

To demonstrate how easy it is to get great natural lighting, we set up this makeshift portrait studio in an empty car garage. When the garage door is open and the sun is overhead, it serves as a large window light source, perfect for portraits.

Our initial result is quite good. The light on our model's face gradually transitions from light to dark to create a natural sense of depth and the background is nicely out of focus due to our aperture setting of f/3.5.

In order to reduce the contrast in a portrait setup, it is common to use a reflector to fill in the shadow areas of the face. To demonstrate this effect, we set up a soft gold light reflector disc on a light disc holder and light stand and positioned it to the right side of our model's face to serve as a "warm fill" light. We then increased the resolution setting to high quality JPEG and took another shot (figures 9 & 10).

The result shows that the shadow side has lightened considerably, and yet there is still a sense of dimension to the face. This classic "main and fill" lighting setup is used often, as it is very flattering to many people's faces.

But, remember that when it comes to lighting portraits, there is no "right" way and that it is always good to experiment with different setups. For some people, increasing the contrast may make it more flattering. This is particularly true for men. To illustrate, we simply replaced the soft gold reflector disc with a black light-absorptive disc to create a "negative" fill. Lastly, we set the resolution to super high quality JPEG and took another shot (figures 11 & 12).

Notice the difference the black disc made. The shadow side is much darker now and the angled features of our model are much more pronounced.

Keep in mind, however, that how you choose to light someone is a matter of personal taste. Having a few different reflector discs and light-absorber discs at your disposal allows you to come up with the look you're after.

DOWNLOADING AND PREPARING FOR PRINT
In order to download your new images onto your computer to manipulate, email, or print them, you may need to install the camera software that came with your camera if you don't own photo-editing software such as Adobe Photoshop. After you've successfully installed this software onto your computer, you can follow these next sequences.

When you want to import the images onto your computer, there are a couple of ways to do it. One way is to connect the camera directly to your computer using a USB cable (figures 13 and 14).

Another way is to use a USB or FireWire card reader. This allows you a little more freedom with where the camera is situated.

For instance, if you have the camera mounted to a tripod and you want to review the images before striking your set, you need to make sure the computer is within the relatively short USB cable distance to the camera. Otherwise, you have to remove the camera from the set to download the images. With a card reader, all you have to do is remove the card from the camera and insert it into the reader.

Once you've connected your camera or media card reader to your computer, a card icon will appear on your desktop (for Macs) or as an external drive (for PC) allowing you to then view, edit, and save the images onto your computer.

We printed the standard quality JPEG, high quality JPEG and super high quality JPEG versions of our model and placed them next to each other. Here, you can see the differences in print sizes from the various resolution settings (figure 16).

Keep in mind that you will get a higher quality 8x10" print from the super high quality JPEG setting than from the standard quality JPEG or high quality JPEG settings. So before you shoot photos for email, web sites, or prints, remember to set your resolution accordingly.

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