Sensor Wars, How Big is Big Enough?Posted on: Sep 05, 2009
Digital 101: Sensor Wars
I believe everyone reading this is old enough to remember when a 2 Mega Pixel Digital camera was really big. I remember being awestruck by the clarity of sports shots taken by one of the dad’s of my son’s high school water polo team with a 2 MP Nikon. That was five years ago! In the digital world, five years seems like another century. Today most sensors on pro cameras are larger than 10 MP and smaller than 22 MP with a few specialty backs in the 33 to 39 MP range. Let’s do the math. One mega pixel when opened up into a tiff file becomes 3 megabytes in 8 bit color. In 16 bit color it becomes 6 megabytes. For simplicity sake, let’s stick with 8 bit color. If your camera has a 12 MP sensor, it will create a 36 megabyte file in its native format. A 22 MP sensor can create a 66 megabyte file. A 33 MP sensor (and they exist) makes a very cute 100 megabyte file in 8 bit. If you demand 16 bit color, then we are talking about 200 megabytes per file.
You can see where I am going here. How big is your hard drive and just how much processing power does your computer have? A 36 megabyte image will comfortably fill an 11×17 spread or make an excellent 16×24 print. A 100 megabyte file will give you a 30×40″ print with enough detail that you can count the pores on a on a person’s face. Most of you require images that can basically fill up a printed page or somewhat larger, but rarely do you need a photo that can fill up an entire wall. Ironically, there does come a point of diminishing returns in the “Mega Pixel Arms Race.” As chip makers squeeze more and more pixels onto a chip, image quality actually declines. The pixels become noisier and less able to render color correctly. I don’t know where this arms race will end, but it might just stop with the issue of storing and handling of very large files. I recommend that our clients archive a master tiff file in as large and stable a format as they can and then make smaller files from the original to use in everyday applications like websites and proposals. The images on this page for example are about 3/4 of a megabyte, but created from a much larger one. Digital imaging will continue to get better, but most of the future improvements will be in software and ease of camera use, and not in giant file sizes.