Side by side
Canon RF 100-400mm f/5.6-8 IS USM vs Canon RF 100-500mm f/4.5-7.1 L IS 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 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.