The Canon RF 24-105mm f/4-7.1 IS STM and the Canon RF 24-105mm f/4L IS USM cover the same focal range, but they are aimed at different buyers. The f/4-7.1 STM is a lighter, simpler everyday zoom, while the f/4L is the L-series version with a constant aperture and a more rugged build. Confirm exact size, weight, and features on Canon’s pages before you decide.
What Each Lens Is For
A 24-105mm zoom is a classic all-rounder. It handles wide landscapes, street scenes, family events, travel, and moderate portraits. The STM version is meant for people who want a capable, easy to carry lens for general use. The L version is meant for users who shoot more demanding work and want consistent exposure as they zoom.
Key Differences
| Trait | RF 24-105mm f/4-7.1 STM | RF 24-105mm f/4L USM |
|---|---|---|
| Aperture | Variable, f/4 to f/7.1 | Constant f/4 |
| Series | Standard line | L series |
| Focus motor | STM | USM |
| Intended user | Travel and everyday | Demanding work |
The most useful difference is aperture behavior. With a variable aperture the lens gets slower as you zoom to 105mm, so you may need a higher ISO or a slower shutter speed. A constant f/4 stays the same across the range, which keeps exposure settings predictable and can give a little more background separation at the long end.
How to Decide
- Think about when you shoot. Mostly outdoors in daylight favors the lighter lens. Indoors or in dim venues favors the constant aperture.
- Consider how much you carry. A smaller lens is easier for all-day travel.
- Look at build needs. L-series lenses typically offer more weather resistance and a sturdier construction, which Canon describes on its pages.
- Think about your other lenses. If you will add fast primes for low light, the lighter zoom may be all you need.
Tips for a 24-105mm Zoom
- Use the wide end for scenes and the long end for portraits and details.
- Rely on in-lens stabilization for handheld work at slower shutter speeds.
- Stop down slightly, to roughly f/5.6 to f/8, for landscapes as a general baseline range.
If you also shoot video, pay extra attention to how each lens behaves while zooming and focusing. Constant aperture helps keep exposure steady, and focus motor design can affect how smooth and quiet focus changes appear. Look at the makers’ descriptions and sample clips to decide which behavior matters most for your projects.
FAQ
Is a constant aperture important?
It is helpful in changing light and for video work, where consistent exposure is useful while zooming.
Can the lighter lens be good enough?
For many people yes, especially for travel and daytime use.
The Short Version
Choose the Canon RF 24-105mm f/4-7.1 IS STM if you want a light, simple zoom for travel and everyday use. Choose the RF 24-105mm f/4L IS USM if you want a constant aperture and a sturdier L-series build. We have not used either lens ourselves.
