Side by side
Canon RF 100-400mm f/5.6-8 IS USM vs Canon EF 100-400mm f/4.5-5.6L IS II USM
Canon RF 100-400mm f/5.6-8 IS USM
358 positive (82%) · 52 mixed (12%) · 25 negative (6%)
Trust + time weighted: +76%
AI summary — not a quote
The Canon RF 100-400mm f/5.6-8 IS USM is highly regarded as a high-value, entry-level telephoto lens that exceeds expectations for its price point. Users frequently praise its lightweight design and surprisingly fast autofocus, which is capable of tracking small, quick subjects like insects and birds. While it is considered a 'dream team' lens for hobbyists on a budget, its narrow maximum aperture (f/8 at the long end) presents significant challenges in low-light conditions, leading to grainy images or lower keeper rates in overcast weather.
Pros
- Excellent value for the price, often cited as the best budget telephoto for the RF system.
- Remarkably lightweight and compact, making it ideal for travel and handheld use.
- Fast and capable autofocus that can handle challenging subjects like dragonflies.
- Sharpness is generally good, often outperforming older EF-mount equivalents.
Cons
- Slow maximum aperture (f/8 at 400mm) limits performance in low light or indoors.
- Image quality can become soft at the 400mm focal length.
- Performance degrades significantly in overcast or rainy conditions, resulting in high ISO noise.
- Reported issues with image quality degradation when using UV filters.
Top excerpts
The RF 100-400 is a light and (relatively) cheap tele.
It's oddly faster and cheaper than the RF 100-400 while theoretically keeping a good autofocus speed and IS, so there must be a catch, right?
I've heard good things about the RF 100-400. It's not that fast but the autofocus is good and it has IS.
I feel like selling it to get a 100-400 would make more sense, since those lenses fill a similar role.
I'd go with the rf100-400
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.