Choosing A SLR Lens

I was so ignorant when purchasing my first two lenses for my Canon Camera! It has nothing to do with it being a canon camera or a second or third party lens. I really didn't even know what I just said till it cost me money on a lens I couldn't use on my new Canon Camera. When buying camera lenses know what all those numbers, abbreviations and letters stand for. Know what a telephoto lens is; compared to a zoom lens, or what a telephoto zoom lens and what is a third party lens? Know if the lenses on the camera you have now or if they will fit the camera that you might buy down the road. There is no since in buying the same type of lenses you have on your old camera, for new camera when you can make sure the lenses are compatible with the new camera.

I bought a Canon 50D for sports shots and then a year later I wanted a Canon 5D for landscapes; and when I tried to use my wide angle lens I bought for the 50D on my 5D it wouldn't fit right. The lens mounted on the new camera alright, but there was a big dark ring when I looked through the view finder. I was sickened with the thought that I will have to purchase a new wide angle lens for the camera I had just bought for landscape photography. My thought was a canon lens will mount to a canon camera, not knowing that higher end cameras have different mounts, or that the size of the cameras processor would matter. I never really given much thought to all the letter and numbers associated with a Canon EF 100 - 400 f/4.5 - 5.6 L IS USM Telephoto Zoom Lens. So let me break it down for you.

I prefer Canon Camera myself so when I buy Canon Lenses there for EOS cameras which is Electro Optical System. But the EF on the Canon Lens stands for Electro Focus. Canon Lenses have the motor built into the lens. The EF lenses are compatible with all there EOS cameras. And there is also an EF-S line of Canon Lenses and they don't fit all EOS Cameras. The EF-S lenses have a smaller image circle that protrude farther toward the camera and will not fit Canons full frame digital bodies like the 5D or the 1DS. When you see 100 - 400 is the focal length of the lens and is measured in millimeters. The f/4.5 to 5.6 refers to the F stop. This is the aperture size of the lens the smaller the number the faster the lens is. And what they mean by a faster lens is the aperture is wider and takes less light for taking shots in low light situations.

The L which is just after that stands for luxury some people clam it stands for low Dispersion UD glass. I've read in several articles where these are the main two answers. But no matter what it really stands for the L signifies this is a professional lens. No matter what sporting event you go to or what event is taking place that is being photographed by a photographer making a living with his or her camera and lens. If they are shooting with a canon camera most likely, their using an L series lens. This is identified by the red stripe that goes around the front end of the camera lens. The IS means the lens is equipped with an image stabilizer, and the USM stands for Ultra Sonic Motor. A telephoto lens will magnify images at a much farther distance and make them look closer than what they are. A zoom lens will bring a subject in closer as similar to a point and shoot camera with a zoom.

When somebody refers to a lens as a first party or a third party lens; what this means is a first party lens is made by the camera manufacture and probably is the best fit for your camera but is usually more expensive than a third party lens. A third party lens, you guessed it, is made by a lens manufacturer that make lenses for all camera makers. These lenses are most likely compatible with your camera and will do an excellent job for you and are usually a couple hundred dollars cheaper than the first party lenses. And I myself love saving a buck, but the next lens I buy for my Canon 5D will be a first party lens.

Article by Alan Slagle

Canon DSLR kit lens upgrade group test : A ten minute video tour comparing the three most popular upgrade options for the Canon 18-55mm DSLR kit lens, by Gordon Laing, Editor of To find out more about these lenses and how their quality compares, see our full review by clicking the link at the start of this text.

Canon EF 50mm f/1.2 L USM Lens for Canon Digital SLR Cameras


Canon EF 50mm f/1.2 L USM Lens for Canon Digital SLR Cameras

The Canon EF 50mm f/1.2L USM lens is a peerless standard lens for Canon digital SLR cameras. The lens is suitable for any shooting situation, with a lens coating and construction type that are optimized to minimize the ghosting and flare that frequently occurs when lenses are used with digital cameras.

Image of women taken with Canon 50mm L lens

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The Moment It Clicks: Photography Secrets from One of the World's Top Shooters


Joe McNally, one of the world's top pro digital photographers, whose celebrated work has graced the pages of Sports Illustrated, Time, and National Geographic (to name a few), breaks new ground by doing something no photography book has ever done—blending the rich, stunning images and elegant layout of a coffee-table book with the invaluable training, no-nonsense insights, and photography secrets usually found only in those rare, best-of-breed educational books.