Side by side
Canon EF 100-400mm f/4.5-5.6L IS II USM vs Canon RF 100-500mm f/4.5-7.1 L IS USM
Canon EF 100-400mm f/4.5-5.6L IS II USM
45 positive (88%) · 5 mixed (10%) · 1 negative (2%)
Trust + time weighted: +85%
AI summary — not a quote
The Canon EF 100-400mm f/4.5-5.6L IS II USM is widely regarded as a professional-grade 'gold standard' zoom lens, praised for its exceptional sharpness, robust build quality, and fast autofocus. While it is an older EF-mount lens, it remains a top recommendation for wildlife and bird photography, even when adapted to mirrorless systems. Its primary drawback is its significant weight and 'hefty' profile compared to newer RF alternatives.
Pros
- Exceptional sharpness and image quality, often compared to prime lens performance
- Professional 'L' series build quality with weather sealing and durability
- Excellent performance when paired with 1.4x teleconverters
- Fast and reliable autofocus that remains competitive on modern mirrorless bodies
Cons
- Heavy and bulky (approx. 1.5kg to 1.7kg), which can be fatiguing for handheld use
- Manual focus ring is prone to accidental bumps due to its placement
- Mechanically linked manual focus ring cannot be disabled via camera settings in AF mode
Top excerpts
Nice! Is that a 100-400 II? Loved that lens.
Works great, performance is excellent, it’s just a hefty package. ... the only negative is the weight. It’s 1550g, 1700 with tripod ring and lens hood, plus RF adapter. RF 100-400 is 665g, and while there’s an IQ difference, I notice that I grab the RF 100-400 way more often, especially to pair with R50, it’s a bit overwhelmed by the chonk of EF 100-400 L ii.
Someone else mentioned EF 100-400 L ii as an option, I’ll just share that I love that lens, it was my first really great long lens, it remains one of the best and sharpest handheld daylight zooms available…
The EF 100-400 L ii was one of the best handheld wildlife lenses in the world when introduced, and remains a contender in that category.
The EF 100-400 II is a much better lens in all aspects than the RF 100-400 IMHO. ... while both lenses are excellent performers in their own right, the EF II has a brighter aperture range (not by very much but every bit counts). The build quality of the EF II is much better but then also weighs a lot more so if weight is a major point for selection then the RF wins hands down here.
Canon RF 100-500mm f/4.5-7.1 L IS USM
168 positive (77%) · 39 mixed (18%) · 12 negative (5%)
Trust + time weighted: +73%
AI summary — not a quote
The Canon RF 100-500mm f/4.5-7.1 L IS USM is widely considered the premier versatile telephoto zoom for the Canon RF system, particularly favored for wildlife and bird photography. Users consistently praise its 'razor sharp' optical performance, fast autofocus, and surprisingly manageable weight for a lens of its reach. While the f/7.1 aperture at the long end is a frequent point of discussion, most owners find the trade-off acceptable for the portability and image quality provided, though some find the high price tag difficult to justify compared to the much cheaper RF 100-400mm.
Pros
- Exceptional sharpness and image clarity across the zoom range
- Fast and reliable autofocus that performs well even on crop-sensor bodies like the R7
- Lightweight and compact enough for handheld use and long hikes
- Superior build quality and weather sealing typical of the 'L' series
Cons
- Slow maximum aperture (f/7.1) at the 500mm end can limit performance in low light
- High price point, with some users questioning if it is worth the significant premium over the RF 100-400mm
- Ergonomic issues with the focus ring being placed too close to the camera body, making it difficult to balance when manual focusing
- Physical design prevents the lens from being fully retracted when a teleconverter is attached
Top excerpts
Both are heavy, expensive "L" lenses designed to offer great optical quality.
Razor sharp
I highly recommend the 100-500. Absolutely my fav birding lens and it’s the natural upgrade form the 100-400 when switching to the R system.
Once you use it, you notice the pictures look so much better, not just sharpness, but also rendition, clarity, color, etc… the keeper rated is also much higher than any lens worked with. Bottom line it just works and it always pleases, if that makes sense. I think it’s been optimized with the R cameras. ... the 100-500 is my fav birding lenses considering the weight, performance and value.
This is in contrast to e.g. the RF 100-500 where the TC offers noticeably more real detail increase than merely cropping.