No, this won’t be a classic in-depth review like the ones you’re used to seeing on Photography Life. I spent too little time with both the Canon RF 200-800mm lens and the Canon EOS R7 for that. In fact, I only used this combo for a few days during which my usual 500mm f/4 suddenly “fell ill.” Before it spontaneously recovered after a few days of bedrest (how, it remains a complete mystery to me), some friends lent me their backup equipment.
And that’s how I ended up shooting with an APS-C camera and the slowest lens I’ve ever tested. Is this combination even usable in the darkness of the tropical cloud forest? This article will explore the answer to that question.
When I realized that my trusty f/4 telephoto lens was no longer working, I mentally prepared myself for the fact that my photo shoot in Ecuador was over. Hearing that the loaner lens maxed out at f/9 on the long end didn’t exactly lift my spirits, especially when I wasn’t even using it on full-frame.
But then I thought: opportunities like this don’t come often. Under normal circumstances, I would never bring such a slow lens into the tropical mountain forests. So I decided to shift my mindset and kept shooting.
Table of Contents
Noise, Dynamic Range, and Motion Blur
The wide-open maw of a fast aperture prime lens is like a photon magnet, greedily gobbling up every scrap of light that happens to pass by. This lets you shoot at comfortably fast shutter speeds or low ISO values — ideally both. The same simply cannot be said of an f/9 lens. (For basic information about the relationship between aperture, shutter speed, and ISO, I recommend our article here.)
When using the Canon RF 200-800mm f/6.3-9, it was necessary to make some compromises. Raising the ISO was my first choice because you can always combat noise to some extent. But there is also a decrease in dynamic range, and a general dullness of colors at high ISO. Sometimes I found myself pushing the other variable, shutter speed, instead — but only for very still and patient birds like owls, nightjars, or potoos.
Forests, especially tropical ones, are notoriously dark. About 92% of sunlight gets absorbed by the canopy above, leaving very little for us photographers to work with. If most of what little remains is stolen by a narrow aperture, the resulting ISO and shutter speed values don’t give much cause for cheer. ISO 32,000 and 1/50s are really the absolute edge, in my opinion. (For comparison, an aperture of f/4 would have allowed me to use a much more reasonable ISO 6400 at the same shutter speed.)
At such extreme ISO values, you have to expect a lot of noise. Even more so with a camera equipped with a high-resolution 32.5MP APS-C sensor. Nevertheless, after denoising in DxO Pure RAW and subsequent processing in Capture One, I found the resulting photos to be quite usable. Maybe I didn’t need to lament my missing 500mm f/4 too much after all!
Fortunately, where there is no light, there is often minimal contrast. So I didn’t run into any serious issues with the camera’s dynamic range. The “Highlights” and “Shadows” sliders had enough room to work their magic, with the possible exception of sky peeking through the leaves. But that’s normal even at low ISO values and entirely forgivable.
With motion blur, however, it’s a different story. The narrow aperture pushes you to the limits of shutter speeds, where you can only hope that your subject will remain as still as a sphinx. That’s hardly a recipe for action photography. I see this as the biggest practical limitation of slow aperture lenses like this one. Unless, of course, you take it as a creative challenge and dive into the world of intentional camera movement photography, like Jiří Hřebíček does.
When I wanted to photograph moving subjects with this lens, I needed to go out into the open a little bit and avoid the darkness of the dense cloud forest. It wasn’t impossible to get some bird-in-flight photos once I did that.
Autofocus
On one hand, exotic prime lenses often come equipped with stronger and more powerful focusing motors. However, those motors usually have to push around larger, heavier glass elements. The differences in focusing speed in real life are not that significant, and sometimes even favor a cheaper lens. The RF 200-800mm f/6.3-9 focused plenty fast for my situation.
What I was more concerned about wasn’t speed, but reliability — specifically how dependable autofocus would be when limited by a narrow aperture and thus very little light. In dark forests or at the edges of the day, cameras can sometimes struggle, even at f/4 or f/2.8. So what happens at f/9? Would animal eye detection still work?
To my pleasant surprise, the AF performance didn’t suffer nearly as much as I had feared. As long as the subject stayed reasonably still (preferably completely still), the camera was able to detect the eye even in the gloomy forest shadows. And in spots where the canopy opened up and allowed a little more light to filter through, autofocus worked reliably even with more agile subjects. It seemed as though the greater depth of field at f/9 made it easier to find the subject in the viewfinder, both for the camera and for me.
Bokeh Quality and Depth of Field
Personally, I like my images to feel “tidy.” That doesn’t mean the background always has to be turned into a creamy pea soup with no trace of environmental context. But in the messy, chaotic disorder of a tropical forest, it’s often helpful to suppress visual distractions by pushing them outside the depth of field. And aperture size plays a major role in determining just how deep that field is.
That said, the effect is not as major as photographers sometimes think. Check out my article Depth of Field in Wildlife Photography to see the practical differences of shooting at different aperture values. With the right technique, even an f/9 lens can lead to creamy backgrounds… right? Well, let’s see how the 200-800mm f/6.3-9 performs.
To sum up, the Canon RF 200-800mm’s out-of-focus rendering isn’t anything to write home about, but that doesn’t mean the photos will have bad bokeh. If you can position your subject against the right background, you can get beautiful blur in your photos with this lens. You just need to think more about the character of the background and the distances between the camera, subject, and background. Accept that sometimes you just won’t be able to figure it out. And keep in mind that bokeh is less about your lens, more about you.
Sharpness
Even though zoom lenses have come a long way in recent years, the old truth still holds — a quality prime will almost always outperform a zoom in terms of sharpness. Most modern zooms deliver perfectly adequate resolution for general use. Still, if you’re printing really large or cropping heavily, fine detail may start to blur and texture may begin to smear. So how will this four-times telephoto zoom perform under close scrutiny?
If you manage to avoid the pitfalls of motion blur, the Canon RF 200-800mm is capable of rendering a great deal of detail. I don’t have objective values from our lab, but I would be really interested to see how this lens compares to similarly priced telephoto zooms, such as the Nikon Z 180-600mm f/5.6-6.3 VR, Sony FE 200-600mm f/5.6-6.3 G OSS, or Fujifilm XF 150-600mm f/5.6-8 R LM OIS WR. Most likely, it will measure a little worse, but it is still well within the range I would call “sharp.”
These are 100% crops of some of the photos throughout this article. They all look nice and crispy to me, and keep in mind that these are cropped from a 33 megapixel APS-C camera, so the pixel size is already very small:
Conclusion
If you’re a Canon shooter with a passion for wildlife photography, you basically have two paths when it comes to lenses. Either you choose the uncompromising path of super-fast, but also super-expensive and large exotic telephoto lenses, or you go for one of the seriously slow lenses. The only hint of a middle ground is the Canon RF 100-500mm f/4.5-7.1 L IS USM and, sometime in the future, perhaps the Canon RF 200-500mm f/5.6L IS USM (if the rumors prove to be true).
But as I found out in the field, even the humble f/9 on the Canon RF 200-800mm f/6.3-9 IS USM is plenty for most situations. As long as you’re not shooting in the darkest depths of the forest — where you’ll inevitably run into issues with high ISO, slow shutter speeds, and motion blur — this lens can deliver impressive reach (especially on an APS-C body) and perfectly respectable image quality. Even under the towering canopy of a rainforest, it’s not entirely out of its depth. It just asks you to slow down and seek out more static subjects. For $2,099, that seems like a fair trade.
I believe that many of you have much more extensive experience with this lens, or with other lenses with a maximum aperture of around f/8 or less. I’d love to hear your thoughts and field experience in the comments. I wish you good light, no matter how small the aperture it passes through.
Very nice shots in a challenging environment. Really, f/9 isn’t that bad for 800mm. The 600mm f/6.3 cropped to 800mm FOV will get as much light as a 800mm f/8.4, which is only 0.2 stops away from f/9, for example. And cropping the 500mm to 800mm is the same as an 800m f/6.4, which is almost exactly a one-stop difference. Obviously, at 500mm the f/4 will be vastly superior though.