What is a Canon L-series lens ?

imageCanon sell a number of lenses in a special series they refer to as L for “luxury.” These are their most expensive and highest-quality lenses, and are readily identifiable by the red stripe painted around the end of the barrel.

L series lenses offer higher optical quality than their non-L equivalents, and have an important technical aspect in common. At least one element in every L lens is either made of fluorite crystal rather than glass, is a ground aspheric lens element (not a moulded/replicated aspheric lens as used in less expensive lenses) or is made from ultra-low dispersion glass. Most L series lenses are also sturdily built - many are encased in metal barrels and most are weatherproofed - and most are very fast lenses for their focal lengths. Nearly all telephoto L series lenses are also off-white rather than black.

These lenses are, therefore, marketed as professional camera lenses and are usually priced out of the range of most consumers. They can be used to take great photographs, but the cost, weight and size of these lenses are the tradeoffs.

Of course, a lens doesn’t have to be an L series lens to take good pictures. Many EOS lenses offer excellent optical quality - they just don’t need and thus don’t have exotic fluorite lens elements and so on. Many of Canon’s prime lenses in the 35mm to 135mm range fit in this category - see below. And some recent EF-S lenses offer near-L image quality but lack the red ring and the tough build quality of contemporary L series lenses.

Note also that the presence of a red ring around the end of a lens barrel only indicates an L series lens if it’s actually made by Canon. Some other makers happily paint red stripes around the end of their lenses too, but this in no way guarantees that the lens meets the quality standard of a Canon L lens.

Check out the list of “L-Series Canon Lenses”.

What is USM in camera lens mean ?

Canon_EF_S_15_85mm_cropIf you notice your Canon digital SLR camera lens has the letters USM written on the side, it means the lens has a small motor built into the body. Hence, USM is short for Ultrasonic Motor.

It is important to note that there are two different types of USM lenses. A Ring ultrasonic, is the one you want to purchase. Then there are Micro motor ultrasonic drives that Canon places into their cheaper lenses. Unfortunately, they also letter these cheaper versions with USM as well. While these cheaper versions are quieter, they don't however focus as quickly as a true ring ultrasonic lens. Therefore, you need to check the lens specifications before purchasing to ensure it is a ring ultrasonic lens, and not a cheaper version created for what is rumored to be marketing reasons.

Advantages of using Canons range of ring USM camera lens?
  • The main advantage of using a ring USM, is that the motor is built into the lens so that it can auto focus faster than a standard lens.
  • Canon's USM / Ultrasonic Motors, are also famous for being quieter than standard motors used in cheaper lenses. This is useful for wildlife photographers, where animals and insects could become spooked from noisy camera parts.
Disadvantages to using a USM camera lens?
  • A USM lens will cost you a little extra than one without it.
  • USM lenses are generally heavier than standard ones. You might need to take this into account if like me, you tend to carry around 3 at a time.

How are ISO, Shutter Speed and Aperture related ?

triangle-of-photographyHere it is: the one chart you’ll ever need to understand shutter speed, aperture, and ISO. It will help you to create better black and white photos, it helps to explain why your lenses are more important than your camera, how to get the most of them, etc. If you don’t understand any of this, take a look at our guide to terminology [Link below]. Or…take it with you.This chart will help you with the dark art of metering and shooting out in the field, like at pop culture events.

Source: The Photographer