source:http://ezinearticles.com/?id=2205422

Do you ever feel indecisive when selecting a lens for your DSLR? I know it is very annoyance, because cost of lens is one of the consideration.

So, before choosing a lens, ask yourself what you need, what is the object you want to captured using the lens? So, below is the three main factor that need to be considered before you buy your lens to suit your DSLR camera.

1.Focal Length
2.Prime or Zoom
3.Maximum Aperture

Focal Length
Distance of the objects is the impact to decide the focal length. Nearer object using shorter focal length, and further object using longer focal length. So, how to decide the number of focal length? Here is some example.

below 35mm: Landscapes and Interiors
35mm to 70mm: Portraits
70mm to 300mm: Portraits and Sports
300mm and higher: Wildlife and Sports

Prime or Zoom
Prime lens is the lens that cannot zoom in or zoom out, but Zoom lens can do so. Zoom actually is controlling the focal length. Probably people will ask, why still have to choose for prime lens if I got better choice that can be zoom as I like? Here is some simple comparison.

Cost: For same specification, prime lens is cheaper than zoom lens.
Quality: Most people are agree this, the picture taken by prime lens is better than zoom lens.
Weight: Prime lens is lighter, zoom lens is heavier.
Speed: In term of aperture, prime lens is faster than zoom lens.

Flexibility: If you want to capture photo for all focal length such as landscape, interior, portrait, sport. You just need one zoom lens to zoom in and zoom out. If you prefer prime lens, may be you need three.
Price: Do you think total cost for three prime lenses will cheaper than one zoom lens?
Portability: Do you think carry three prime lenses will easier than one zoom lens?

Maximum Aperture
Now what is the reason we have to decide the maximum aperture for a lens? Because the lenses have the wider maximum aperture normally are costly. Wider aperture allow more light in, narrower aperture allow less light in. If you taking indoor picture, the light condition indoor is not as good as outdoor, so you need wider aperture to let more light in, if not, the picture you taken will look dark.

Another reason is to suit shutter speed. We need faster shutter speed to take picture for fast object. When your shutter speed is set to very short period, example 1/2000 second (just 0.005 second), and you do not set your aperture wider, then the picture you taken will become underexposure, it look dark.

Last, is about the depth of field, the blurry background is caused by this impact. Wider aperture is decrease the depth of field, background blurry; narrower aperture is increase the depth of field, background clearly.

As conclusion of this topic, it is all about the monetary problem. If I do not consider about my economy status, I will choose focal length with 18mm – 300mm, zoom lens, maximum aperture by 1. But reality is cruel, I have to be more intellect, so I choose focal length 50mm, prime lens, with maximum aperture by 3.5.

DSLR Lens Study

Article Source: http://EzineArticles.com/?expert=Chuan_Wen_Ng

Source:http://www.the-digital-picture.com/Canon-Lenses/Canon-Lens-Selection-Introduction.aspx

You are being diligent. You are being responsible. But the more you research your lens purchase, the more confused you become. There are a huge number of Canon lenses available and a near-infinite number of Canon lens combinations available.

Well, you can relax. You are certainly not the only one that is confused. And the good news is that, most likely, there is more than one Canon lens that can adequately accomplish your goals.

I will attempt to make some recommendations for lenses for popular photography subjects. In the event that you select the wrong lens, most of the vendors supporting this site will let you return it in new condition for a refund/exchange within their reasonable return policies.

First, I have a couple of questions to ask you …

How much is the right lens worth to you? How much are you willing to spend to capture excellent images of your children before they grow up? How much are you going to make using the lens as a pro? What are you going to lose if your lens does not perform up to expectations? How long do you expect the lens to last? How hard are you going to use the lens? In what weather conditions do you expect to use the lens?
Do you need a Zoom or Prime Lens?

What Focal Length do you need? Getting this question wrong can, in some situations, render a lens nearly useless to you, regardless of how awesome the lens’ image quality is.

What Maximum Aperture do you need to stop camera shake or stop the action?

Now keep in mind how much you have spent for your awesome new DSLR body. You are going to be wasting much of that money if you put an inferior lens on it.

Find the recommendation category closest to your need. Then read the reviews for the suggested lenses (and other similar lenses) to make your decision.

Selecting the right lens is critical when purchasing a digital camera. Basically, lenses can be categorized this way: fixed focal length, retractable zoom, fixed zoom and interchangeable lenses.