For those who aren't aware, this lens is the second of Canon's nano USM lens, following the EFS 18-135 USM that came in a kit with the 80D. It has a very similar construction, using Canon's new premium consumer modern look-and-feel, that's a huge step up in construction of the 55-250 STM, which is still a great lens and should be considered for its price if you're looking for a non-pro telephoto Canon.First, the bad. I really don't like the nano USM manual focus ring. It's electronic, meaning that when you turn the focus dial (which feels great, by the way), electronic signals are sent to focus the lens. It's not a constant change -- twist fast, and it changes in a big jump, and turn slow, and the stepping is tiny. It also doesn't work while it's off or in sleep mode, so you have to press the shutter halfway to wake it. I strongly prefer ring USM (which is on practically every Canon pro lens), which has a straight-forward, turn the focus ring and focus changes, regardless of whether you're in AF or MF. This is my only real criticism of the 70-300 USM.Now, the good. The lowdown is that it's a midrange priced lens that gives you pictures nearly as good as much more expensive options in most situations. A lot of non-professionals just can't afford to spend thousands of dollars on a 300mm zoom that has IS. It's also much lighter than Canon L zoom lenses, and it's usable without a tripod (though obviously, tripod is preferred for many situations).The autofocus on this lens is very fast and silent, though I think slightly slower than the 18-135 USM. If you like that lens, you'll love this one: it has very similar construction, with Canon's new, premium consumer-modern look-and-feel. It's definitely a step up in quality and sturdiness (and has a lot more glass and weight) than the 55-250, and AF is vastly improved over the old 70-300. The layout situates IS and AF switches aligned on the left, and the zoom lock on the opposite side. It is very slightly larger than its predecessor.Taking just a few quick shots outside with an 80D to test the lens, the pictures appear sharp in all the corners in that sweet spot between f5.6 - f11. In good lighting, both viewfinder and Live View AF on 80D is amazingly instant and totally quiet, for those who want to use this to shoot video. In poor lighting, AF is still fast. I think that regardless of your use case, if you have DPAF, and want to shoot in AF, this lens is a beast. So, with videos and fast-moving wildlife or sports the nano USM will let you capture a sharply focused target and snap the picture to capture that that magic moment.On a T6s, which does not have Dual Pixel autofofocus, AF through the viewfinder is instant and fluid; AF through liveview may have a little hunting if the focal distance changes a lot. I suspect that if live view shooting is your thing, you'll probably find slow-moving subjects just fine, performance most videos acceptable, fast-moving subjects acceptable but a little less than ideal (eg some wildlife shots where instant focus is appreciated).So, for instance, using this lens, tap-and-snap of a hummingbird on an 80D is nearly instant, whereas on a t6s, there's the tiniest pause while it acquires focus. Through the viewfinder, there's effectively no difference.This lens has a variable aperture at 4.5-5.6; of course, I'd prefer f4 at all focal lengths or better. But realistically, at the price point of this lens, that's just not going to happen, or many other sacrifices have to be made (like prime lens instead of zoom, no IS, etc.).Other things: Like all non L lens, it doesn't come with a lens hood, which is a pity. Also, this takes 67mm, so there is a slight premium when buying a B+W or Hoya filter. Since that's an unusual size, that most people don't have a spare filter for, expect to add another $50 or so.In short, a great, new mid-range addition to Canon's lens collection for those of us who don't want to go crazy on pro lens.

As a photographer I can always recommend Canon. This is a great product and it really has only few downfalls to it.1. AF is very slow, so busy scenes are not for this product2. With adapter to use normal EF-S lenses the AF slows down even further3. EF-M lens availability is very limited, which brings you back to the point 2 above.But you get bang for your buck if you can live with the above. Digic 5 processor, touchscreen and the great Canon quality if you shoot more portraits, night scenes and landscapes in general. If you have few canon ef-s lenses you like and need cheap but great EOS experience on the road while not wanting to carry e.g. heavier 6D, 5D bodies... then this is great way to go!

I use this extender with my 70-200/2.8, 300, 400, and 500mm tele lenses for wildlife shooting (hobby). My cameras: 7D, now upgraded to a 7D II, and a 5D III. Important in particular for 2x TC users: both latter cameras still provide an active center field autofocus with lens+TC combos that have an F/8 initial aperture. In particular every birder knows: you can't get enough focal length. And if you don't want to invest in - and carry - a super huge & heavy 800mm lens, you have to have TC's in your backpack. I use Canon's very good 1.4x MK III TC frequently, and less frequently this 2x TC. Many reviewer's here explained already the 2x TC's technical pros and cons in detail. In real life, according to my experience, you can break it down to those three items that really count:(1) images lose visibly sharpness and get softer, in particular in the edges (full frame) but with re-sharpening during post-processing (or sharper pre-settings in your camera) you can get acceptably good results (= you still can see feather/fur textures) IF...(2)... there is enough light available (!!) for a - with many lenses - quite slow combo AND...(3)... the object does not move too fast and unpredictable, because AF will work as sluggish as an old digital compact camera (but accurate with a carefully micro adjusted camera).This may also be important for you:- Oh no, you can't combine Canon's Mark III 1.4x with 2x TC's to shoot man's first footsteps on Moon from Earth. Canon prevented this mechanically, not only by some sort of pins (you could easily remove): the whole TC's do fit because their lens systems extend from their bodies and would collide before their bayonets snap together. Don't complain, be sure that the image quality of such combos would be too lousy anyway for modern high res sensors. If you need extreme focal lengths check if digiscoping (mostly without AF) would be the better solution for you.- Some lenses do not fit with Canon's Mark III TC's because, again, their extended lens systems would literally collide with the back lenses too close to the bayonet. The example in Canon's lens line that I presume is most prone to such a disappointment is the macro lens EF 100mm/2.8 L IS USM. So check the TC's compatibility with the lenses you want to use it with before you hit the order button. Btw you can pimp your macro's magnification by using extension tubes, plenty of good ones with full electronic supply of AF and aperture are available.Final word(s):Given the fact that a 2x TC is always a quite extreme optical compromise, the Canon engineers did a decent job with the Mk III version. But do not expect any wonders. An EF 400/5.6 lens will always be much sharper at 400mm - and focus much quicker - than a 70-200/2.8 II + 2x TC III combo, I can tell from my own experience.Those who just start with the TC business, I'd highly recommend to go first for Canon's 1.4x TC Mk III. It provides less reach but much better optical and AF performance. In practice you can use it much more frequently and get good results.

Automatic AF is very smooth. Pictures seem clearer than the stock 18-135mm that comes with the Canon 70D...you can tell its much newer. For $125 this is the best lens to get i promise

EOS-Rで使用。純正Canon以外含むEE レンズ３本とEF-Sレンズ７本、普通に使えました。EF-SレンズのクロップはCanon製は自動で、シグマのArt 30mm F1.4 DC HSM、シグマの17-50mm F2.8 EX DC OS HSMも自動、タムロンの16-300mm(B016E)とトキナーのAT-X 11-20mm F2.8 PRO DXは手動で設定が必要でした。EOS-Rは80Dからの買い替えですが、どのレンズもAFの速さは変わりないです。正直なところダメ元で買いましたが手持ちレンズ全てが動作し、嬉しい誤算です。質感も約７千円の値段を考慮すれば十分です。KenkoのTELEPLUS HD C-AF 2X DGX との組み合わせはレンズによってエラーが出て作動しませんでした。使える場合でも流石にAFは遅くなります。

I’ve had the canon eos 5d classic as a hobby. It was good for me, but this eos r has a great af and picture quality. I think this eos r camera works as a real upgrade for me, I’m very satisfied with its like-new condition as well.

I bought this to use with my Canon 80d. So far it seems to work perfectly, including the AF assist beam which is an issue with some other versions. This is the 2nd Yongnuo flash I now own. Great quality and so much cheaper than the Canon alternative. I would highly recommend this item.

It is the first 600mm lens that can be really hand-held which is a selling point to hobbyists. It just weights 2 lbs and creats a good balance on my Canon RP camera. The OS system works well. I can understand why this is not a pro lens since STM and mirrorless focus are not fast enough and F11 is too dim for pros. The lens is not weather-proved either. But these applications are not mission critical for most bird-hobbists. If you need a lens you can carry effortlessly from your neck on a sunny day and leave your tripod behind, this is the lens for you. It works OK when it is cloudy. But ISO over 10,000 will introduce some visible noise and lower sharpness. On a sunny day, when ISO is below 1000, Canon Digic 8 processor gives completely noise free full-frame images which blows you away in sharpness. That's why I keep it. On low light conditions, a hobbist like me would not try to shoot birds and will carry other fast weather-sealed lenses. I like the big focus ring and in-viewfinder focal distance display which really help to manual focus and supplement the slow AF. It works and no stressed muscles anywhere makes the hobby more enjoyable than laboring. To give another AF tip after a few days of use, set your camera to servo AF instead of single-shot AF will be a lot faster on a STM long lens like this. This will drain battery faster so get a couple of more batteries.