Lens Simulator
EN
English Deutsch Français Italiano Español Nederlands Polski

Canon RF 135mm F1.8 L IS USM vs. Canon 135mm f/2 L

Pick the 135mm f/1.8 if you want about 11% more background blur, pick the 135mm f/2 if you want less background blur. Compare both side by side.

Loading scene…
0%

Portrait At-a-Glance Comparison (Upper Body Framing)

Optical & Portrait Metric Canon RF 135mm F1.8 L IS USM Canon 135mm f/2 L What It Means in Practice
Upper-Body Working Distance 5.40 m 5.40 m Identical working distance—both frame an upper-body portrait from the exact same spot.
Background Field of View (Compression) 15° 15° Identical 15° horizontal background view behind the subject.
Entrance Pupil Diameter 75.0 mm (f/1.8) 67.5 mm (f/2) Distant background blur discs are 11% larger on the Canon RF 135mm F1.8 L IS USM.
Corner Bokeh Roundness (90% Field) 62% (-0.6 EV) 89% (-0.2 EV) Canon 135mm f/2 L keeps significantly rounder bokeh balls into the corners wide open (89% vs. 62% roundness).
Effective Focal Length (Breathing) 132.7 mm (-1.7%) 138.8 mm (+2.8%) At 5.4 m, Canon RF 135mm F1.8 L IS USM frames like a 132.7 mm lens while Canon 135mm f/2 L frames like a 138.8 mm lens.
Depth of Field (Sharp Zone) 25 cm (5.28 m – 5.53 m) 28 cm (5.27 m – 5.55 m) The Canon RF 135mm F1.8 L IS USM has a 10% thinner focus zone (25 cm vs. 28 cm)—requiring more precise eye focus.
Minimum Focus Distance 0.7 m 0.9 m Canon RF 135mm F1.8 L IS USM focuses 20 cm closer (0.7 m vs. 0.9 m) for tighter close-ups.

Questions

Which blurs the background more, Canon RF 135mm F1.8 L IS USM or Canon 135mm f/2 L?

At the same subject framing, distant background blur scales with the entrance pupil diameter (focal length ÷ f-number). Canon RF 135mm F1.8 L IS USM at f/1.8 has a 75.0 mm entrance pupil, while Canon 135mm f/2 L at f/2 has a 67.5 mm entrance pupil.

How does working distance differ between Canon RF 135mm F1.8 L IS USM and Canon 135mm f/2 L?

For an upper-body portrait, Canon RF 135mm F1.8 L IS USM stands 5.40 m from the subject (sharp zone 25 cm, from 5.28 m to 5.53 m), whereas Canon 135mm f/2 L stands 5.40 m away (sharp zone 28 cm, from 5.27 m to 5.55 m).

How do the optical designs of Canon RF 135mm F1.8 L IS USM and Canon 135mm f/2 L compare?

Canon RF 135mm F1.8 L IS USM uses 17 elements in 12 groups (US20230213745A1, effective focal length 132.7 mm at portrait distance). Canon 135mm f/2 L uses 10 elements in 8 groups (JP2018-049102A, effective focal length 138.8 mm).

Explore individual lens ray-tracers

Head-to-head lens comparisons

All lens comparisons

Also see: depth of field, bokeh, crop factor, lens compression.