Find what you are looking for

or search by

Topics

Article
Article

Article

e-Book
e-Book

e-Book

Video
Video

Video

Campaigns
Campaigns

Campaigns

Architecture
Compact Cameras

Compact Cameras

Architecture
DSLRs

DSLRs

Architecture
Videography

Videography

Architecture
Astrophotography

Astrophotography

Architecture
Mirrorless Cameras

Mirrorless Cameras

Architecture
Architecture Photography

Architecture Photography

Architecture
Canon Technologies

Canon Technologies

Architecture
Low Light Photography

Low Light Photography

Architecture
Photographer Interviews

Photographer Interviews

Architecture
Landscape Photography

Landscape Photography

Architecture
Macro Photography

Macro Photography

Architecture
Sports Photography

Sports Photography

Architecture
Travel Photography

Travel Photography

Architecture
Underwater Photography

Underwater Photography

Architecture
Photography Concepts & Application

Photography Concepts & Application

Architecture
Street Photography

Street Photography

Architecture
Full-Frame Mirrorless Cameras

Full-Frame Mirrorless Cameras

Architecture
Lenses & Accessories

Lenses & Accessories

Architecture
Nature & Wildlife Photography

Nature & Wildlife Photography

Architecture
Portrait Photography

Portrait Photography

Architecture
Night Photography

Night Photography

Architecture
Pet Photography

Pet Photography

Architecture
Printing Solutions

Printing Solutions

Architecture
Product Reviews

Product Reviews

Architecture
Wedding Photography

Wedding Photography

Products >> All Products Key Features of RF Lenses- Part

RF50mm f/1.8 STM vs. RF50mm f/1.2L USM: What’s the Difference?

2023-08-17
17
11.17 k

What are 50mm prime lenses, and what can you do with them? In this article, we share why and introduce two 50mm RF lenses: the RF50mm f/1.8 STM and the RF50mm f/1.2L USM.

In this article:

Introduction: The attraction of 50mm prime lenses

Introduction: The attraction of 50mm prime lenses

EOS R6 + RF50mm f/1.2L USM @ f/1.2, 1/1600 sec, ISO 200


1. A natural perspective that better captures the human eye sees

50mm lenses are known to have the least visible distortion, which means they capture a natural perspective very similar to what the human eye sees. You won’t have to worry about things at the corners looking strangely stretched, like you might have encountered when taking phone selfies. This makes them easier to work with especially for beginners, regardless of whether you are shooting up close or from further away.

EOS R5 + RF50mm f/1.8 STM @ f/16, 1/2 sec, ISO 12800


2. Easy to compose: Frame scenes close to the way you see them

EOS R3 + RF50mm f/1.8 STM @ f/1.8, 1/60 sec, ISO 12800

When you look in front of you, your central field of view is around 50 to 60 degrees. The 39.6-degree angle of view on a 50mm lens is slightly narrower: enough to easily leave distractions out of the frame and create eye-catching compositions of the scene that fascinates you.

(In reality, the angle of view can also be measured vertically and diagonally. But for easier understanding, we’ve taken the horizontal angle of view as a reference.)


Frame full-body portraits from a comfortable distance away

EOS R5 + RF50mm f/1.2L USM @ f/1.2, 1/160 sec, ISO 640


Examples shot on 50mm lenses

 

You may be interested in:
50mm Portraits, My Style: Creating A Picture of a Memory
EF50mm f/1.8 STM: A Review with Useful Composition Tips

Canon’s two RF 50mm prime lenses

Canon’s two RF 50mm prime lenses

Canon has two 50mm prime lenses with large maximum apertures that achieve beautiful bokeh. One is the compact and inexpensive RF50mm f/1.8 STM “nifty fifty”. The other is the professional RF50mm f/1.2L USM, a favourite among many professional photographers due to its very large aperture and reliability.

This table shows the key differences between them. Scroll on for more details!


Main differences

  RF50mm f/1.8 STM RF50mm f/1.2L USM
Size Small and compact Bigger
Dimensions (approx.) 69 x 40mm 89.8 x 108mm
Weight (approx.) Approx. 160g Approx. 950g
Maximum aperture f/1.8 f/1.2
Weather sealing No Yes
Quality Standard Professional quality

You may be interested in:
RF50mm f/1.8 STM vs EF50mm f/1.8 STM: 6 Key Comparisons
Lens Impressions: RF50mm f/1.2L USM in Portraits & Street Photography

Difference #1: Bokeh

1. Bokeh

EOS R5 + RF50mm f/1.8 STM @ f/1.8, 1/125 sec, ISO 200

Both lenses are considered “fast lenses” as they have large maximum apertures. This has two advantages:

1. They allow you to use a faster shutter speed and/or lower ISO speed in poorer lighting, which achieves sharper images.
2. They create beautiful bokeh that blurs out the background and/or foreground. You can use this to isolate subjects or achieve a dreamy look!

RF50mm f/1.2L USM at max aperture

RF50mm f/1.8 STM at max aperture

The RF50mm f/1.2L USM has the larger maximum aperture (f/1.2), which achieves more intense bokeh.


Real-world comparison: Different lenses, different bokeh quality

This doesn’t mean that both lenses give the same bokeh quality at f/1.8. Here’s what happened when we stopped down the RF50mm f/1.2L USM to f/1.8.

RF50mm f/1.2L USM at f/1.8

RF50mm f/1.8 STM at f/1.8


Close-up

The bokeh on the L lens looks smoother and creamier. Much engineering effort went into ensuring bokeh quality that would meet the needs of professional photographers.

Difference #2: Impact on bokeh performance

2. AF performance

EOS R6 + RF50mm f/1.2L USM @ f/1.2, 1/160 sec, ISO 3200

The larger the maximum aperture, the easier it is to focus even under challenging conditions. One example is this black dog at night where there is little contrast. A larger maximum aperture allows more light to enter the camera. More light means more information for the autofocus system—and better focusing accuracy!

Difference #3: Weather-sealing and durability

3. Weather-sealing and durability

Like other L-series lenses, the RF50mm f/1.2L USM adopts a dust- and drip-resistant design that prevents dust and moisture from entering the lens. This gives it better reliability and durability when shooting in harsh or unpredictable weather conditions.

It also features oil- and dirt-repellent fluorine coating on the front and rear lens surfaces for easier removal of fingerprints and smudges.

Difference #4: Image quality

4. Image quality

All lenses have inherent issues that affect image quality. These are corrected in different ways to different degrees on the RF50mm f/1.2L USM and RF50mm f/1.8 STM:

RF50mm f/1.8 STM RF50mm f/1.2L USM

A: PMO aspherical lens

A: Aspherical lens elements
B: UD lens elements
Reduce ghosting and flaring
- Super Spectra Coating
- Optimised lens element shapes
Air Sphere Coating
Correct colour fringing, improve sharpness, etc
PMo (Plastic Molded) aspherical lens - 2 x ground aspherical lenses
- GMo (Glass Molded) aspherical lens 
- UD lens

As a professional grade lens, the RF50mm f/1.2L USM incorporates more special glass to ensure the best possible image quality even under challenging conditions, such as those with the sun in the frame.

What is ghosting and flaring? Learn more in:
Lens FAQ #4: What is “ghosting” and “flaring”?


Real-world comparison: Performance with strong lighting in the frame

RF50mm f/1.2L USM at f/16, 8 sec, ISO 100

RF50mm f/1.8 STM at f/16, 8 sec, ISO 100

No visible ghosting here

Ghosting is visible as a blue-coloured smudge.


Know this: Ghosting and flaring usually occur when there is a strong light source in the frame, although this also depends on the angle at which the light enters the lens.

Difference #5: Controls and switches

5. Controls and switches

The RF50mm f/1.8 STM has a very simple design with just one ring and one Control/Focus switch. The switch changes the function of the ring.

The RF50mm f/1.2L USM has two rings and two switches:
- Focus ring
- Control ring
- AF/MF switch
- Focus limiting switch

You can switch to manual focusing with just a flip of the switch. The focus limiting switch provides more control over the focusing distance.

Difference #6: Closest focusing distance

6. Close-up shooting

The RF50mm f/1.8 STM has a shorter closest focusing distance (30cm) compared to the RF50mm f/1.2L USM (40cm), allowing it to focus on objects that are nearer. The images below, both shot at 50mm, show how this affects your photos. The first close-up image is possible only on the RF50mm f/1.8 STM.

30cm focusing distance

40cm focusing distance

In both images, the lens’ field of view remains the same, but the subject fills more of the frame when the lens is closer to it, as the 30cm focusing distance example shows.  Being able to focus close-up is important when photographing food, small objects, or details.

Also see:
Lens FAQ: What Images Can I Get with 0.25x or 0.5x Magnification?

Key specifications: RF50mm f/1.8 STM vs. RF50mm f/1.2L USM

Key specifications: RF50mm f/1.8 STM vs. RF50mm f/1.2L USM

  RF50mm f/1.8 STM RF50mm f/1.2L USM
Size 69.2 x 40.5mm 89.8 x 108mm
Weight 160g 950g
Widest aperture f/1.8 f/1.2
Narrowest aperture f/22 f/16
Aperture blades 7 (circular) 10 (circular)
Closest focusing distance 30cm 40cm
Maximum magnification ratio 0.25x 0.19x
No. of lens elements and groups 6 elements in 5 groups 15 elements in 9 groups
Special lenses PMo aspherical lens x 1 Ground aspherical lenses x 2
GMo aspherical lens x 1
UD lens
Special coatings Super Spectra Coating Fluorine coating
ASC (Air Sphere Coating)
Switches and controls Combined focus/control ring
Control/focus switch
Control ring
Focus ring
Focus limiting switch
AF/MF switch
Image stabilizer No No
Mount material Metal Metal
Dust and drip-resistance No Yes
Filter size 43mm 77mm

 


Which lens will you choose?


RF50mm f/1.8 STM

RF50mm f/1.2L USM


Need help deciding on which lens to get next? See:
Prime Lens or Zoom Lens: Which Should I Buy?
10 Concepts to Know Before Buying Your Second Lens

Share your photos on My Canon Story & stand a chance to be featured on our social media platforms