CanonRF800/11 is STM(N)

I gave this great Lens a 4 instead of a 5 due to the fixed F/11 aperture. However, I did not do so due to the limitations in low light that everyone is talking about. The Canon R5 manages high ISOs quite well. Instead, the issue I have with the fixed F/11 aperture is the lack of flexibility in Depth of Field (DOF) which may well be many magnitudes more of an issue with the usefulness of this Lens than is the light issue. Read on. In this review I will not go into all the technical details of the new Canon RF 800mm F/11 Prime Lens. You can get that in many places. This Lens really is a game changer. What I will discuss are some limitations of this lens that should not be a surprise to anyone, but which I overlooked when I first started to shoot with it. While the RF 800mm F/11 is a great Lens you need to understand the differences and limitations between the new 800mm and the 400mm that most of you may have used in the past as your go-to long Lens. But first some background. I have had a passion for photography since age 8 when I got my first camera. This was a large rectangular box camera handed down within the family, that was 62 years ago. Along the way I have used a large collection of film and digital cameras and their lenses, including Minolta, Sony, Nikon, and Canon. For the last 16 years I have been solidly a Canon user and have owned every EOS 5D camera made. Along the way I had harbored a deep desire to own a Canon prime super-telephoto lens to get greater reach and presumed superior image quality as I do a lot of nature and bird photography. A few years back I did buy the EF-500mm f4L IS II prime lens. Even though I had read all the specs and reviews many times, when I first opened the box I was shocked by how big and heavy it was. I tested the 500mm lens image quality against my EF 100-400mm F/4.5-5.6 L IS II using both lenses on two different cameras (5D Mk III and a 5DsR) mounted on a heavy tripod with a delayed shutter release. After shooting nearly a thousand photos at all apertures and viewing the 500mm images at 100% and the 400mm lens images at 125% side by side I found the 500mm Prime lens really had no advantage over the 100-400mm Zoom in image quality. I sent the 500mm Prime back.Fast forward to 2020 and the release of the Canon EOS R5. Along with the EOS R5 I bought the RF 800mm F/11 IS. Being absolutely giddy to finally have an 800mm lens I skipped the at-home research and testing and headed straight for my favorite duck pond. I shot a few hundred photos of individual ducks, and groups of ducks, at distances between 50 ft and 150 ft as I always did at this pond. I shot hand-held, and on a sturdy monopod. I shot in Flexible Mode at 1/200 sec (mistake 1) with auto ISO. I had always shot at 1/200 Sec. for non-flight shots and they had come out great. Of course, the aperture is always F/11 and I assumed that this aperture would provide plenty of Depth-of-Field (Mistake 2). All photos looked fine on the camera-back display so I headed home to view them on a large computer screen. Nearly all of the photos were unacceptably blurry where I did not want any blur. The photos fell into groups. Individual ducks at rest were quite sharp except that some ducts around 50 ft distant had portions of the duck blurry. Individual ducks that were swimming were all generally blurry. In groups of ducks, the duck at the focus point was mostly sharp, if at rest, but ducks only a foot or two feet away were quite blurry. None of the photos appeared to be blurry due to camera shake, even the hand-held ones. This is when the light bulb came on that I had skipped the step of understanding the substantial limitations of this lens at relatively short range compared to the 400mm Lens I had normally used for this purpose. You need to understand these limitations in order to successfully use this lens at ranges of 25 to 200 ft. This is what I found.Fist lets look at why the shutter speed of 1/200 did not stop the motion of a swimming duck. The 400mm lens had an Angle of View of 5.15 degrees providing a Horizontal Field of View of 9 ft. at 100 ft distance. The 800mm Lens has an Angle of View of 2.58 degrees providing a Horizontal Field of View at 100 ft of only 4.5 ft. This means the swimming duck will move across the camera’s focal plane in half the time. If 1/200 sec always worked well with the 400mm Lens, then I would need to use 1/400 sec to get consistently crisp photos of swimming ducks using the 800mm Lens. As for the F/11 fixed aperture much has been written concerning limitations in low light, but little has been said about the lack of flexibility in Dept of Field (actually, no flexibility). Since this lens has a fixed aperture the Depth of Field is strictly a function of distance to your subject. At 100 ft the Depth of Field at F/11 using the 400mm Lens is 12 feet. At 100 ft using the 800mm Lens the Depth of Field is reduced to only 3 ft. This is 1.5 ft in front of your subject and 1.5 ft beyond the subject. At 75 ft range the Dept of Field for the 800mm Lens is reduced to 20 inches, or 10 inches in front of, and 10 inches beyond your focus point. At the minimal focus range of the 800mm Lens (about 25 ft) the Dept of Field is 1 inch. I suggest you download or build your own Depth of Field table for an 800mm Lens at F/11 aperture and keep it handy until you have pretty much committed it to memory. Armed with this new knowledge I went back to the pond and selectively picked my shots factoring in the DOF limitations of the 800mm Lens and was rewarded with a much greater % of great keepers. However, it was clear that I would always need to also take my EF100-400 zoom along, probably mounted on a second camera, so as not have to pass up some great shots not attainable with the 800mm.This new 800mm really is a great Lens. There are hundreds of reviews out there that will tell you that. It is lighter than my EF100-400 zoom by 7 ounces, can easily be used hand-held, and is very near as sharp as my 100-400mm zoom, which is an exceptional Lens. However, making the best use of this Lens will involve a much greater awareness of the Lens DOF limitations under 200 ft, or even further, depending on the subject. I will go out on a limb and predict that at least 90% of all photos taken with this 800mm Lens will be at ranges of 300 ft and less for nature photography. This is due to its’ light weight and ease of use compared to the big Super Telephoto Primes. I would consider this new Lens to be a walk-around Lens at least from an ease of use standpoint. By the way, at 300 ft the Depth of Field for this lens is decent 27 ft. Hyperfocal distance is 6580 ft which would be great for bringing the mountains up close over the water. If you have invested in the EOS R5, get yourself a Canon RF 800mm F/11 Prime Lens to go with it. If used properly, you will not be disappointed.

I wanted to review this since I agonized over the purchase for 2 months. I've been using an adapted 100-400 zoom with a 1.4x extender. Though I get great images with that combination, there are still subjects that are too far away. I was debating on a 2x extender or this lens. Both have been back-ordered and this lens was back in stock first so I took a chance.Before I get into the pros and cons, I will start by saying that I would recommend this lens as long as you understand what you are getting yourself into. It isn't as well built nor does it produce the image quality of an L lens but it costs 1/3 of what my 100-400 cost. It is also infinitely less expensive than a prime L.Pros:-Reasonably fast focusing. I was able to attempt some birds in flight photos. I was able to track and take pictures but there was not enough light for higher shutter speeds that are necessary for clear images.-Lighter than an L lens since there is not as much glass nor is there much metal. The only noticeable metal is the mounting ring.-800mm for an incredibly reasonable cost. I was able to take some image that I would not have even attempted with my 100-400 w/1.4x costing much more.-Decent image quality. My first outing was an overcast morning and I was hand-holding. Though I got some reasonable images, there was some obvious camera shake. Based on the Grebe chick image I included that was taken with some sunlight, hand held shots are possible. A monopod is recommended.Cons:-Center focus area. This isn't an issue for distant subjects. It does become an issue if the subject is a little closer. I am used to the edge-to-edge focusing on my R5. There were some situations where I could not get eye focus if I wanted to frame my subject properly. I could have swapped out for my other lens but that is at the risk of missing a shot.-f/11 aperture. Having stated that, it isn't really an issue in my case nor would it be an issue if you own an R6 as well. You can really push the ISO on the R5 and R6 before noise becomes a problem. The Cinnamon Teal was at 2500 ISO. Anything below 8000 is fine on my R5. On this overcast day, the highest ISO reached was 6400 and that was because my shutter speed was at 1250 for 'action' shots. Lowest ISO was 800 at 1/320 shutter speed. I could have gone slower but would have likely encountered worse camera shake.-Not as well built as an L. It doesn't seem 'cheap' as I have seen it described but the jury is out on how long this lens will last. More important, it is not weather proofed. I can also see potential issues with the slide mechanism used to put the lens in shooting mode. Sand or dirt could cause problems.-Lens hood and tripod ring/mount not included. Though cheaper than an L mount lens that will come with a both, Canon could have at least included a hood.Again, I am happy with my purchase and would recommend for those that own an R5 or R6. The reach is incredible for the price. Having spent a morning with the lens, I have a better understanding on how to use it. As for whether a 2x extender is a better option, it could be if you already own a good 400mm lens. You would still experience aperture and center focus issues like you do with the RF 800mm. There are also some EF lenses not compatible with the 2x.ADDENDUM: I was able to take the lens out on a sunny day. The higher shutter speed on bright days makes it easier to hand hold the lens. For reference, the Killdeer image is taken at 1/1000 with an ISO of 1000 due to the dark background. The eagle 30 feet up in a tree is cropped taken at 1/1000 and 1600 ISO. Though not tack sharp like an L, it is still pretty good. Subjects with a light background will drop the ISO with the lowest I saw was at 500 with a 1/640 shutter speed.

I am a very amateur photographer, learning a new camera and a new lens. It is difficult for me to find my subject at times but that is user error/inexperience not the lens. Would not hesitate to buy again

Didn’t pay attention to the fixed lens part. Wouldn’t recommend for wildlife. Mainly birds, manual focus works better than auto focus. Could be better quality as well but fairly durable.