A zoom lens offers a lot of convenience and versatility. Let’s explore the different types of zoom lenses and some unique zoom lens characteristics.

EOS RP/ RF24-105mm f/4-7.1 IS STM @ 70mm, f/11, 1/320 sec, ISO 100

 

1 zoom lens, countless possibilities

Benefits
- More flexibility composing shots.
- You don’t have to keep changing your lens.

Weaknesses
- “Darker” maximum aperture compared to prime lenses.

 

What is a zoom lens?

A zoom lens is one of the most versatile types of lenses available. You can simply turn the zoom ring to change your framing. This makes them convenient, versatile, and easy for even beginners to use. It’s why kit lenses—the lenses that are sold in a set with new cameras—are usually zoom lenses.

 

All images above shot on: EOS RP + RF24-105mm f/4-7.1 IS STM

What do you do when you see an interesting building from afar and want to frame it in different ways? Moving closer to the building might not be physically possible, and even if it were, you’d get a very different point of view standing right under it. A zoom lens helps you get wide shots and close ups from the same spot just by turning the zoom ring.

Introducing focal range: How much can my zoom lens cover?

How wide or zoomed in a zoom lens can go is reflected in the lens name and on the lens body. It is expressed in terms of focal lengths.

For example, the RF24-105mm f/4-7.1 IS STM has a focal range of 24-105mm.  Its widest angle of view is at its 24mm “wide end”, and it zooms in to 105mm—the “tele” or “long” end.

As the diagram shows, maximum aperture aside, a 24-105mm standard zoom lens covers the same focal range as at least 6 different prime lenses.

 

Key concept (1): Types of zoom lenses

There are four types of zoom lenses. Wide-angle zoom lenses enable you to capture a wide area of the scene. Standard zoom lenses and superzoom lenses cover a wide range of focal lengths including telephoto ranges. Meanwhile, telephoto zoom lenses enable you to capture close-up images of faraway subjects.

You might be interested in: 
Lens FAQ #9: What is the difference between an f/2.8 and an f/4 telephoto zoom lens?

Examples of wide-angle zoom lenses
(1) RF14-35mm f/4L IS USM 
(2) RF15-30mm f/4.5-6.3 IS STM
(3) RF-S10-18mm f/4.5-6.3 IS STM

Examples of standard zoom lenses
(1) RF24-105mm f/4L IS USM
(2) RF24-105mm f/4-7.1L IS STM
(3) RF28-70mm f/2.8 IS STM
(4) RF-S18-45mm f/4.5-6.3 IS STM (for APS-C cameras)

Examples of superzoom lenses
(1) RF24-240mm f/4-6.3 IS USM
(2) RF-S18-150mm f/3.5-6.3 IS STM

Examples of telephoto and super telephoto zoom lenses
(1) RF70-200mm f/4L IS USM
(2) RF100-400mm f/5.6-8 IS USM
(3) RF-S55-210mm f/5-7.1 IS STM 

 

Key concept (2): Variable aperture and constant apertures lenses

Another way of categorising zoom lenses is by their maximum aperture, which is indicated in the lens name. If the maximum aperture changes as you zoom in, it’s a variable aperture zoom lens. If it stays the same throughout, it’s a constant aperture zoom lens.

Constant aperture zoom lenses are appealing because they allow the same amount of light to enter the lens even at longer focal lengths. However, they tend to be larger, heavier, and more expensive than similar variable aperture zoom lenses due to their more complex design.

Canon has two 24-105mm RF lenses that are often included as kit lens options for full-frame EOS R series cameras.

The RF24-105mm f/4-7.1 IS STM is a variable aperture zoom lens—you can tell because its aperture is stated as a range. It’s lighter and more portable than its constant aperture counterpart, the RF24-105mm f/4L IS USM, but the latter offers more flexibility.

The changing maximum aperture on the RF24-105mm f/4-7.1 IS STM

As you zoom in, the shrinking maximum aperture reduces light entering the lens. You will have to use a slower shutter speed and/or higher ISO speed to maintain the same brightness. The bokeh intensity also changes.

 

Key concept (3): Maximum aperture and bokeh

The shrinking maximum aperture on variable aperture zoom lenses means less intense background bokeh at longer focal lengths compared to a constant aperture zoom lens.

On this particular variable aperture zoom lens, the maximum f-number at 105mm is f/7.1: 1 2/3  f-stops narrower than the constant aperture lens. Notice the difference in the bokeh.

Also see:
Prime Lens or Zoom Lens: Which Should I Buy?
Camera Basics #1: Aperture
Lens FAQ #6: My Zoom Lens Doesn’t Have a Very Bright Maximum Aperture. How Can I Get a Large Bokeh Out of It?