An interesting vision trend is that the whole camera industry is undergoing a technology revival. The last revival in the vision industry was for cheap, reliable, and bright LED lighting. While this was incredible, at the end of the day it was simply a bright light. Not much to talk about really, even though it was fun at the beginning. The most recent technology revival is being caused by the flood of new camera imagers from the consumer cell phone camera industry. A camera imager is the device that takes the photons and turns them into digital values. An imager has millions of the digital photon receptors, and each one is called a pixel.
In the past, vision engineers treasured their large imagers in the 1” or 2/3” format, selecting CCD over CMOS because of the higher dynamic capabilities of the CCD imager. 1 megapixel, 2 megapixel and 5 megapixel were the usual bus stops for machine vision engineers, and each bus stop usually cost a thousand dollars per stop or so. This was pretty much carved in the stone tablets that came down from the mountain, and us vision guys rolled with it on the various jobs we encountered. Throw in a $250, $500, or $1200 lens for each stop, and you have a camera. If your problem was particularly involved and single pixel accuracy was demanded (or you needed a lower F number), then maybe doubling the lens cost could get you where you needed to be.
Now, with the availability of tiny, much higher pixel imagers from the cell phone market being offered at virtually giveaway prices, we now have many cameras being offered well above 5mp at a price point where 2 megapixel or even 1 megapixel cameras used to live, each of them with a microscopic imager suitable for use in a cell phone. These tiny imagers put huge demands on the lens to resolve the focus point down to 2 microns or less. Since the limit of focus-ability of light is somewhere around 1 micron, this pressure on the lens manufacturers to create small, nearly perfect lenses at a reasonable cost is immense. In the past, a 5mp lens needed to be 2/3” format to be commercially viable (most industrial imagers were 1”, 2/3” or ½” format), the new imagers are asking for lenses in the ¼” range and smaller that are rated at 10 megapixels.
At the end of the day, the real winner is the customer – more pixels on your problem for the same $ usually means better, more repeatable results.
This means that the stodgy lens manufacturers are having to re-tool their whole industry to switch from big format and less-than-perfect lenses to small format and nearly perfect lenses, which means large capital investments and delays to market for the new products. Apple solved this problem with a shift to Sapphire as their lens material, which is not an inexpensive approach unless you are making many millions of them.
So, the current state of affairs is that you can buy small, inexpensive cameras with more than 5 megapixels for about $600, but you will have to buy these huge lenses for them that cost perhaps twice or three times as much as your camera. The first manufacturer to create high megapixel lenses for tiny imagers at a reasonable price will likely own the market for a while. Since the camera market is exploding, the lens manufacturers are likely putting in long hours to capture this revenue.
At the end of the day, the real winner is the customer – more pixels on your problem for the same $ usually means better, more repeatable results. It is a good day to have a problem that can be solved with a vision system, and tomorrow is even looking better!