Canon RF 800mm F11 Review

My review of the Canon RF 800mm F11 lens as a normal photographer, not sponsored.

I don’t normally do this sort of thing, but this particular lens is such an unusual piece of equipment, I thought it might help people who were considering its purchase. I rented a copy from WEX, which costs about £60 for a weekend, which I consider a wise investment to allow you to assess whether this is a product for you. 

First, let’s get some basics out of the way. This lens comes only with a Canon RF mount; this means it can only be used with Canon’s R series of mirrorless cameras, and will NOT work with their DSLR range which has the earlier EF mount. If you have one of those, you may as well stop reading now. 

When you get the lens, it’s in its retracted state, measuring 28.2 cm in length, with a diameter of 10.2 cm. This is its transit mode - to get it to work on the camera, you rotate a locking collar, then extend the barrel, and re-lock the collar. This takes the length up to 35.2cm. For those who are interested in this sort of thing, the lens has 11 elements in 8 groups; if you interested in that sort of thing, you probably should get out more. What is very interesting is that it weighs only 1.26kg - it comes as a real surprise the first time you pick it up, and makes carrying it around really easy. In contrast, my walk-around lens for my R6, the 24-105 f4 L weighs 700g, but the lens in my bag that’s closest in capability, the Sigma 150-600 Contemporary zoom comes in at nearly 2kg. The difference feels even bigger than the numbers suggest, and I would have no issues handholding this lens all day. 

The very unusual thing about this lens is that the aperture is fixed at f11. There is no variable diaphragm in the lens, so f11 is it. This clearly has a number of consequences, meaning that in anything other than very bright light, you’re going to need to bump up the ISO on your camera to get a fast enough shutter speed to take sharp shots. Whilst this is much less of an issue on my R6 than on my crop-sensor 80D, it does mean in typical dull UK winter day conditions, you’re likely to be in the “Swiss cheese” region of the ISO, requiring lots of work in post-processing and generally getting sub-optimal results. I used the lens today in very bright conditions, and could use 100 ISO only when getting down to around 1/200th shutter speed. Happily, the lens has an effective image stabiliser which works in concert with the R6’s in-body stabilisation (IBIS) which makes this theoretically too-slow shutter speed useable. Those with very steady hands might be able to use even slower speeds. Note that if you have an R or RP body without IBIS, I think you’d struggle to go that slow. What this will mean is that people using this lens for aviation photography will have no issues getting decent prop-blur, which I think would be a serious challenge, were one hand-holding a conventional Canon 800mm lens (weight 4.5kg!).

One rather disappointing thing about the lens, given its likely uses (you’re very unlikely to use this lens inside - the closest focussing distance is 6 metres), is that it has no weather sealing at all. This meant that snow stopped play very rapidly on my first day with the lens, since I did not wish to damage either lens or my camera. 

Now let’s get on to my actual experience when using the lens. It feels very well balanced when extended and fitted on the R6; the lens has a tripod mount built-in, which is perfect to attach my Black Rapid strap. It’s worth mentioning again how light the combo is - a three hour walk left me with no issues at all, something that could not be said had I been lugging the Sigma around. In good lighting conditions the focussing is incredibly fast, so quick you don’t really think about it after a while. Things aren’t so rosy however shooting into the light, or in low light, or in low contrast situations. I was shooting gulls in yesterday in flat light with a flat grey sky, and the combination missed focus on every single shot - all 50 or so frames were unusable. In good conditions today, I’d say I was getting a 90% hit rate on flying birds. On static subjects in good light you’ll never miss. One point of note however - the focussing area is limited to the central part of the frame - the full frame focussing point coverage of other lenses is missing. Given the lens’ likely uses, this probably isn’t that much of an issue, to be fair. 

In the right conditions when you’ve hit focus, the lens appears to me to be very sharp, and it captures a lot of detail. The Sigma wide open at 600mm is very much softer than the Canon 800mm, and the Sigma’s not bad in that respect. I’ve included sample images below; some are cropped and some are not - to me it’s the quality of the final image that counts, and I’ll let you be the judge of whether they’re any good. 

One further thought - this is not a lens for the novice, in my opinion. The field of view is so narrow that you have to have a decent amount of experience to be able to pick up your subject before it’s flown/ run off. You don’t have the ability as you would with a zoom to acquire the target on a wide setting, then twist the zoom ring to get the right composition. 

To the $64,000 question then; would I pay the £979 (plus an outrageous £58 for the dedicated lens hood) to have one? I don’t think so; it’s a very specialised lens that is useful in a pretty limited set of circumstances. If I lived somewhere where the light was bright the whole time and was a dedicated wildlife photographer, then it’s a no-brainer, just buy the lens. Here in the UK where it’s dull and grey for significant periods of time and/or raining, it makes much less sense. I think the other group this might appeal to are those who are building an RF system from scratch. The longest zoom currently available is the 100-500mm, and in that context, an 800mm makes more sense. That said, I did enjoy using the lens, and will probably hire a copy if and when the need arises.