Vector vs. Raster Logo: Understanding the Difference Between a Vector and Raster Image-Part II

If we use a photo in your logo, this means the logo is now partially a raster image, and you lose all the benefits of having a vector image. Why does this happen? When a camera takes a photo, it is kind of like using the individual pegs on a LightBrite (or creating a cross-stitch with individual stitches) to create a scene.  The camera creates and stores color information for each pixel (tiny dot, shaped like a square) that makes up the image. When you take a picture, the camera setting determines how many pixels are created and stored in the digital file. The quality of an image is called its “resolution”, measured by calculating how many dots the camera stored per inch (dpi). The resolution of an image taken by a camera can’t be improved later by a designer.

Aaah...memories.

A low-resolution image looks blurry, grainy, or jagged, especially when you zoom in on the image or expand it to a larger size, because you are seeing all of the individual squares. A high-resolution image has more pixels stored per square inch, so if you zoom in or print it at a large size, you still don’t see the individual squares because there are still so many of them. However, once you display the image large enough, it will eventually get blurry–the setting of most digital cameras is such that you can’t print most pictures any larger than 11” X 17” without starting to notice the pixels.

In contrast, creating a vector image is like quickly coloring in entire sections of a picture in a coloring book (or pouring paint into different sections of a multi-section paper plate). This gives a vector image “perfect” resolution–you can expand it to be as large as you want, and you’ll never see any pixels. Using Adobe Illustrator, a designer defines relationships between endpoints in terms of proportion and placement, rather than specific lengths or widths, and can instruct Illustrator to fill in each entire section with color rather than one pixel at a time. Illustrator plays “Connect-the-Dots”, but you never see the dots because it always knows how many to fill in between two points to make a perfect line. Pretty handy, huh?

Why don’t cameras use this shortcut? Why can’t you “take” a vector picture? Well, in a real-life image, the colors are so random and varied that there just aren’t enough relationships to create any shortcuts (or “fill” areas). So how is a logo different? Fortunately the colors in a logo design, unlike a picture, are not random–even if there are multiple colors used in the design, they are not used in a random way. But this doesn’t mean vector designs have to be all flat and boring. There are many techniques, like gradients, with patterns that can be calculated into a vector formula. But certain photographic/3-D effects require so much random color that they can’t be created as a vector file. They must be created (using a program such as Adobe Photoshop) as a raster image, like a photo, one pixel at a time. This is a bad idea because, again, you lose all the advantages of having a vector image.

There are times when you would actually prefer a LOWER resolution for your picture.

Once you understand the basic difference between how vector images and raster images are created, you’ll start to see “Why a Vector Logo Wins”. And here at Businesslogos.com, we want you to have the best!

In Part 3, we’ll show you some examples of vector effects vs. raster effects.