Focused Advice

Nov 1, 2007 12:00 PM

With the various and endless features that make up a camera, finding the perfect device for a facility may seem overwhelming. Ricardo Chen, manager of technical marketing and sales training, Consumer Imaging Group for Canon USA Inc., answers some frequently asked questions about choosing the right security camera.

WHAT are some misconceptions about lenses?

If you just look at the specifications, it's hard to determine an end result. If you're buying a product with a lens, look at the aperture of the lens and the qualities the lens has itself. Is it a glass lens? Does it have coating? The best way to determine this is to test it out. My recommendation is to put competing cameras side-by-side and look at image quality — the details, colors, etc. Make a decision on what you see — not what you read. At the end of the day, when you collect cameras for your system and you are recording and [an incident] occurs, you go back to your video and you just want to see what happened. You aren't thinking of the specs or the properties of the camera. You need to be able to answer, “Was what I just saw white? Beige? Yellow?”

HOW many megapixels do I need?

Megapixel is ultimately a buzzword. At home, a way for you to see more detail on your television is to change from standard to high definition. People who work in the security industry are now demanding that if they can be at home watching video that is so clear that they feel like they are there, then why can't they get cleaner pictures while watching security video? So ultimately, they assume megapixels are what equals high definition. But, one megapixel can look better than five megapixels if you have the right combination of other things.

WHAT are the crucial features I need to look at before choosing a camera?

You want information on the iris, the capture device itself, the focal lens, zoom, aperture, algorithm and image processing. But what you also need, which is information that isn't normally released, is coating. Coating is what minimizes apparition and color distortion. All of those factors decide what a picture looks like. When you are trying to determine what you are seeing from a security video, if all you are seeing are blurry images, images that are not crisp, color distortion, inability to focus correctly, you will see an end result that no matter what the specs tell you, is not what you should be looking at.

HOW do I choose a lens?

You can determine what type of lens you need by what kind of area you want to look at. If it is a small hallway or a lobby, you want the most amount of coverage. If you determine you want a wide-angle lens, you must determine how wide you need or want. How much is covered by that area and how much of that area is in focus? When you read a spec of how much the lens can cover, it doesn't tell you how much of that is in focus. Just seeing a wide-angle image isn't enough. If you have a 42, 56 or 70, it doesn't really help you because ideally if you get a wide-angle lens, you want to see more and an entire area. Unfortunately, the only way to determine that is to see images from competing cameras, side-by-side.

WHICH one: optical or digital zoom?

If you are placing a camera in an area like a parking lot, you want a low-focus lens. But then, you need to decide how much is optical and what's digital. That is a misconception in the marketplace of zoom.

Optical zoom is similar to zooming like on a pair of binoculars. You zoom by bringing the image closer to you. With digital zoom, you eventually reach the end of the zoom, so you digitally enhance the image to blow it up. The image starts to get soft, you lose the edge and it gets blurry fast. Ideally for outdoor cameras, you want the longest optical zoom you can get because once you go digital, you get blurry.

Digital zoom is optimal for cameras that have 10x or 20x zoom and you just need a little more. If you get to 14x or 15x, the image starts breaking up; 20x and 40x gets worse; 60x, 80x, 100x are totally useless. So if you have to use digital zoom, use it moderately. I would say use up to 4x. If you must reach 100x, and you pick 10x and you have to do 10x to enhance, you would get a better picture if you started with 26x. Plus, a 26x with proper coating might give an even better image.

WILL technology keep up with the changing camera innovations around it?

The lenses are the first point where image comes through to the capture device, so a good lens will give you good image quality.

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© 2008 Penton Media Inc.

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