Monday, December 6, 2010

Buying A Camcorder Specs–When A Lens Can Put You Over a Barrel

This time it is a look at lens, optics and straight-up flim-flam. Yes, time once again for an exploration of camcorder specifications. Now I admit I got caught by this one years ago and I made it a point to remember.

Here is an example:
That black stuff does nothing to help record a video. The shape and size of the barrel does not indicate the size of the sensor, the zoom ability or anything else other than supporting the teeny tiny hole that light can enter the camcorder. That teeny tiny hole will only allow so much light and data into the camcorder. Here is another example, the Vivitar DVR 840XHD Camcorder. Vivitar DVR840XHD
The black matting is gone but replaced with plastic and glass. I’m not picking on Vivitar because other vendors do similar things to fool unsuspecting or non-photography aware folks.

The analogy that comes to mind is the guy that stuffs his pants with socks. I’m going for the tubular connection but to be fair I could also say this is like the dame that stuffs her bra with tissues.

Ether way this is false advertising of an implied but missing capacity.

What To Look For In A Lens/Optics


Manufacturers can use either plastic or glass. The can use cheap glass or create a lens free from defects, aberrations and off color fringing. Inexpensive camcorders use plastic only or a combination of plastic and glass. The cool kids on the block use quality optical lenses. That generally does not occur in camcorders under $99.99

Optical Zoom

This is the only zoom that counts. Anything else is just marking hocus pocus. The higher the number the greater the distance you can bring up close. 5x zoom is about 190mm. That is not bad for a pocket camcorder. Sad to say that most pocket camcorders don’t have any optical zoom at all.

On standard definition camcorders you’ll see optical zoom ranges of between 30x to 60x. The high definition camcorders I’ve seen the optical zoom range from 10x to 20x but that will change over time.

In any case, if you think you will be using optical zoom you will need a tripod for anything over 5x. There is no way to hold the device steady enough by hand to prevent the shakes.

Digital Zoom is crap. It just magnifies a certain area of the image or video. If you magnify too much it makes the image look really bad. Dual Zoom or any other indication of more than one zoom systems means that the manufacture is using a combination of optical and digital zoom to make it seem like there is more telephoto than is possible with the lens.

Digital Film Sensitivity

In the analog days film was rated for sensitivity. This meant that certain films were rated according to how well the film recorded with a certain amount of light and detail depending on the recording conditions. Back in the day this was called the ASA number but it is now referred to as an ISO number.

The smaller the ISO number the more light was needed to record the image. The higher the ISO number the less light needed and a shorter amount of time was needed to keep the lens open.

In camcorders here is how it would play out:

  • ISO 50 - You need to be outdoor in bright sunlight. Indoor recording will be bad unless you have a lot of extra light.

  • ISO 100/200 - Still need to be outdoors but a cloudy day is ok. Need extra light for indoor recording.

  • ISO 400 and higher - Outdoors shooting a football game and (depending on the optical zoom, shutter speed and quality of the lens) able to record split second action. Indoors with adequate light will be ok but the video might look a little grainy.

Inexpensive camcorders will have a low ISO sensitivity and the better camcorders will allow you to select the type of ISO sensitivity that you want for your recording. Inexpensive camcorder specification sheets might not even mention ISO numbers. The quality vendor will spell it out in detail.


The smaller the number the more light hits the sensor and the more detail that is recorded. Most pocket camcorders have a f/2.8 lens, that allows a good amount of light in but can be a trade off in terms of focus and depth of field. The higher the f/stop the more light is needed to record the image or video.

For example, f/8 is good for outside on a bright day; the video is sharp and full of color. Yet f/8 could be horrible for inside recoding in a dim lit room. If the camcorder has a fixed f/stop and you need to record indoors that might be a problem. Better to know before you buy.

Shutter Speed

This refers to how quickly the shutter opens and closes to allow light to hit the image sensor. It works in balance with the f/stop, the quality of the lens and the sensitivity of the sensor.

What You Need to Know

If you are in a retail store and are able to look at the camcorder take a look at the lens area. Is it clear or does it have black matting and a very small opening? It should be on the package about the recording capabilities of the device.

If shopping from home please go to the vendor’s web site. Look at the photos and see if you can locate the actual area of the lens. It may be deep inside of the barrel area.

In lower end and inexpensive camcorders the barrel means nothing. There is no optical zoom and digital zoom is crap.

Quality camcorder vendors will tell you the size of the image sensor, the f/stop and the ISO number that refers to the light sensitivity needed to record quality videos.

This is part 5 in my series on how to read camcorder specification information.

Part One - What’s In A Name?
Part Two - Make and Model
Part Three - What Is An Image Sensor?
Part Four - More About Image Sensors?

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