Zoom Camera Lens

Zoom Camera Lens

Would someone please explain to me how the Zoom on a camera lens compares to the X power of a rifle scope?

For example I have 4X power rifle scope which means that what I'm looking at through the scope is magnified four times it's actual size.
How does this work with a zoom lens? Is a 200mm setting three times closer than a 50mm setting?
Is there a formula for figuring this out?

Zoom on a camera only describes the RANGE of focal lengths of the lens.
So a 4X zoom may be from 25-100mm focal length.
A 35mm film camera was the standard for comparing magnification for most photographers (and often it still is). A 50mm lens approximated the diagonal dimension of the film frame so a 50mm lens is refered to as a "normal" lens. It came the closest to what your eye saw at 1X magnification.
That means a 25-100mm zoom lens has a magnification of 1/2X at its widest setting to 2X at its highest magnification.

Power or "x" factor on a scope is MAGNIFICATION. A 4X scope sees and object as if it were 1/4 the true distance to you.

For your question, a 200mm setting is 4X more magnification than a 50mm setting.

When reading specs on a camera, you have to dig down to get the "35mm" equivalent of the particular camera focal length. An 7-28mm zoom may actually translate to 28-112mm in "35mm equivalent" because the CCD sensor on the camera may be only 12mm diagonal.

Here is your formula:

1. Make sure you find the "35mm equivalent" focal lengths of the lenses
2. Divide by 50mm to get your magnification range.
3. If the camera is 35mm film or is an expensive "full frame" sensor, simply divide by 50mm to get your magnification.

Many DSLR's tell you the "conversion factor" of lenses. Typical factors are 1.5, 1.7 and 2. That means when you stick a 100mm lens on a camera with a 1.7 conversion factor, the lens is equivalent to a 170mm lens on a 35mm camera and your magnification is 170mm/50mm = 3.4X

Here are some examples of 35mm equivalent focal lengths:
28mm = 0.56X good wide angle. You can capture nearly an entire bedroom view without "fish-eye" distortion
35mm = 0.7X mild wide angle. Easier to get group shots without backing up too much
50mm = 1X Pretty much what your eye sees in terms of magnification
85mm = 1.7X good portrait lens for face shots
200mm = 4X used to be the consumer limits for inexpensive telephoto shots
500mm = 10X used to be top of the line telephoto. These are the lenses used by those pro photographers that often get tackled on the sidelines of football games .

Hope that helps

Buying a digital Zoom Camera

I use the term Zoom Camera simply because this article is based on personal experience when buying a Canon SX110 IS, which is a compact digital camera with a 10x zoom lens. There are a number of compact digital zoom cameras with 10x up to 20x optical zoom lenses which fall into this category. However, I'm sure my experience can be applied accross the full range of digital cameras from the bottom end 'point and shoot' to the top end professional digital SLR's.

Having decided which camera I wanted, my next task was to obtain the best possible deal and thus the purpose of this article, because what looks like a good deal is often not the best deal.

The best place to start is online which shows up quite a wide range of prices. All the major high street retailers have a website and in most cases they offer a better deal if you buy online than you can get by visiting their shop. There are a number of price comparison sites which make this task a lot easier. However, you need to look beyond the price displayed or ticket price.

Quite often, as in my case, you are not just buying a camera. Look carefully at the 'what's in the box' information. For example, my camera came with only a 32MB SD memory card (only enough for around 6 images), a couple of alkaline batteries and no carrying case. So I decided that I needed a 4GB SD memory card, four rechargeable nickel cadmium batteries (two as spares), a battery recharger and a carrying case. Even if the box contains everything you need right now, it is a good idea to consider what you might need later because bought seperately, these items can add significantly to the overall cost. By bundling these items in with the camera at the time of purchase is the best way to get a good deal.

So don't just look at the ticket price of the camera. Decide what you need to go with it before you start comparing prices. Some online retailers offer huge savings on bundled items. In my case for example, the 'extras' I needed would have cost a total of £87.50 if purchased seperately, yet by bundling them in with the camera I was able to save £34. Even though the ticket price for my camera was higher with this online retailer compared with others their overall bundled price gave me the best deal.

About the Author

Richard Taylor is a keen digital photographer and having spent much time researching the best zoom camera for his own use, decided he would share that by creating a website featuring the top cameras in this category. Comparing prices, technical information, customer reviews and much more http://www.zoom-camera.co.uk

Zoom Camera Lens

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