Canon RF 400mm f/2.8 L IS USM vs Canon RF 800mm f/5.6 L IS USM
Both are Canon RF mount primes for telephoto and wildlife — here's how the specs differ and which to pick. Every spec is from the manufacturer's own catalog.
| Spec | Canon RF 400mm f/2.8 L IS USM | Canon RF 800mm f/5.6 L IS USM |
|---|---|---|
| Focal length | 400mm | 800mm |
| Max aperture | f/2.8 | f/5.6 |
| Type | prime | prime |
| Coverage | full-frame | full-frame |
| Mount | Canon RF | Canon RF |
Which should you buy?
- the Canon RF 400mm f/2.8 L IS USM opens wider (f/2.8) — brighter in low light and more background blur
- the Canon RF 400mm f/2.8 L IS USM (400mm) is wider — more in the frame for street and interiors; the Canon RF 800mm f/5.6 L IS USM (800mm) is tighter — more reach and compression for portraits
Where to buy
Canon RF 400mm f/2.8 L IS USMSee price on Amazon
Canon RF 800mm f/5.6 L IS USMSee price on Amazon
FAQ
What's the difference between the Canon RF 400mm f/2.8 L IS USM and the Canon RF 800mm f/5.6 L IS USM?
The Canon RF 400mm f/2.8 L IS USM is 400mm f/2.8 prime, full-frame; the Canon RF 800mm f/5.6 L IS USM is 800mm f/5.6 prime, full-frame. Both fit the Canon RF mount.
Which is better in low light, the Canon RF 400mm f/2.8 L IS USM or the Canon RF 800mm f/5.6 L IS USM?
The Canon RF 400mm f/2.8 L IS USM — its f/2.8 maximum aperture lets in more light and gives more background blur than the f/5.6 of the other.
Do the Canon RF 400mm f/2.8 L IS USM and Canon RF 800mm f/5.6 L IS USM fit the same camera?
Yes — both are Canon RF mount lenses, so they fit Canon EOS R series (full-frame R5/R6/R8) and APS-C (R7/R10/R50).
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