Canon EF 2X II Extender Telephoto Accessory

The Canon EF 2X II telephoto extender is a reasonably inexpensive way to double the focal length of some of the Canon lenses. There are a few pro's and con's when considering going this route. The image quality of this extender is extremely good and maintains the image quality of the lens that is attached to. I found it to be far better than other lessor cost extenders. There are a couple of caveats to be aware of before purchasing this extender. First, it is NOT compatible with ALL Canon lenses. Check the Canon site for the specs on this extender and the list of compatible lenses. It is mainly a physical problem of the front element of the extender lens sticking out too far to physically connect with some lenses because their rear element is too far back and it clashes (or crashes) with the extender. Secondly, be aware that a 2x extender will cause a 4x light loss through the optical system (i.e. 2 f-stops slower). This is true of any extender - it's the law of optical physics. Unless your main lens is better than F5.6, the camera will not have enough light to autofocus, so be prepared to manually focus your camera when using a 2x extender. That being said and all of these conditions being understood, the Canon EF 2X II extender is a great way to double the power of your telephoto lens.

Because of the mixed reviews about this extender "Canon EF Ex II" I had to buy it to see for myself. I used my canon 70-200 MK II 2.8 on my 5D Mk II and I have to admit I hate the softness and especially the soft edges not to mention the slow focus. It doesn't come close to the performance we all know and love with this fine quality lens. I decided to pack it up and ship it back to the seller I was so disappointed. I'm sure many will think I did something wrong or expected to much, this isn't the case since many others have testified to the same results. If you're happy that's great, I wasn't. I decided to at least try it on my Canon 40D which has a 1.6 crop factor which extends the focal length to 640mm and Viola... the quality is absolutely stellar!!! Not only are the images sharp as a tack with images like the 70-200 without extender, and it focuses extremely fast. Needless to say I'm extremely happy and 40D's aren't very expensive, so if you are unhappy with the 2x II and you can afford a 40D that might be an option considering you get a second camera, longer focal length, fabulous images, for less than $400 on average. Just consider the the extra cost like buying two extenders. Why the four stars? I feel it should work on my 5D MK II with equal results, and it doesn't! Regards, Urban Picasso

Shortly after I purchased my first SLR film camera (some time around 1977) I bought a 2X tele-converter hoping to use it with my 70-200 f/4.5-5.6 zoom lens. It was an off-brand (Spiro-Tone if I remember correctly) and it was awful! It created barrel-distortion and degraded the image far more than I had expected. Well, they have come a long way in the decades since. This 2X extender is designed to work with both fixed-focal length telephoto lenses and long zooms. I purchased this originally to use with my 100-400 zoom and even though the effective maximum aperture at 800mm was f/11 the resulting image was tack sharp. Recently I rented a Canon 400mm f/2.8 L lens and tried it with this converter. Wow!!! It was incredible! I had it mounted on a good sized Gitzo tripod and was able to photograph a small bird from a great distance and it still filled the frame. The effective aperture was only f/5.6 which is what you would expect for a 800mm lens. I hope to purchase a 300 or 400mm f/2.8 in the future and I am sure that I will be getting even more use out of this excellent optical accessory.

I recently purchased the canon 100-400mm L series with auto focus and image stabilazation. Amazon had the extender come up as a recommended buy. The problem is that the extender requires a lens with a 2.8 f stop for the auto focus to work. I tried using the extender withou the auto focus and found it almost impossible to get a clear picture. I'm sure the extender would work well with any of the canon $7000-$10,000 professional telephoto lenes, but not with the 100-400 L series zoom.

Make sure to check the compatibility charts to verify that your lenses will work with this before buying it since only a handful of L series lenses are compatible. If you do already have one or more of these lenses though this is a nice addition. The AF only works with lenses f/2.8 and faster on most camera bodies. You do also give up image quality by putting this between your lens and camera body. When using longer telephoto lenses with this, you will want to use a tripod, cable release, and mirror lockup in all but the brightest of conditions. If you need this much extra reach you may be better off getting a 1.6X camera body or saving up for a longer lens.

I've used the EF 2X II Extender for 9 months now and can say it has met my needs admirably. I say this having researched, knowing the benefits and short comings of using it before I made my purchase. I use it primarily in combination with my EF 100-400mm IS lens for use on birds and outdoor events. I have shots of birds I couldn't have captured had I been required to close in on the subject. It's also been key in closing the gap where I would not be able to cross because of an area being otherwise inaccessible - not worth losing gear or limbs to get a closer vantage point. Now the downside with using the EF 2X II are no Auto Focus and added softness in some shots and of course the increase in F stops. Even in shots with high contrast lighting and a stationary subject, softness in image quality can be an issue. When using it on a mobile subject, I end up with quite a number of shots that I will not use. Between adjusting for focus and the inherent soft IQ, you'll definitely need to weigh its use. A work around for not having Auto Focus through the viewfinder is to use a Hoodman or other device to shield the LCD and shoot in Live View. Using my 7D, I can get AF confirmation and take the shot. If you are good at post processing your images, one could argue not using the extender and simply enlarge an image matching the IQ softness the extender adds. My preference is to go with the optics vs. the software algorithm.

I used it exclusively on my 1DsmkII with the Canon 70-200mm f/2.8 L IS for my month in Jerusalem - originally it was joined to a 5DmkII with the Canon 180 mm f/3.5 L macro lens - also superb image quality. I was very happy about that. Only two problems actually (and they are not problems, just restrictions) and that is the loss of stops (on the 2.8 70-200 lens the widest I could open the aperture was 5.6 and on the 3.5 it was a bit smaller) - tough when shooting churches and darker situations, which I do. The other restriction is I could only use it with those two lenses out of my collection. It does not fit with any glass that is flush on the back end, such as the 85mm L 1.2 or the 35mm L 1.4 or the 24-70mm L 2.8, or the 14mm, or the 24mm.... etc. Mainly made for telephotos so no getting creative with it with the medium and short lenses. I think I would have given it 5 stars if Canon could make it so as to keep the lens f/stop speed at the widest of the lens being used (in my case, 2.8 and 3.5 respectively). With that said, I thought many times on this trip, that it was a great purchase and I am glad for having made it - loved the extra extension and shooting with a smaller lens at a max 400mm length. I am leaving it configured with my 1DsmkII and the 70-200 zoom. I like the results that much. Is it less contrasty? less sharp? Well, not pixel peeping here, I am only asking - did I get the shot or not. And with that I can say YES! (many times in an area sensitive to picture taking). I am glad to have it in my lens case.

As the other reviewers have said, it is a nice option to have in your bag. It is not meant for everyday use to get that incredibly sharp, close-up of birds, animals or people. It is very helpful when the shot is very difficult to make without it. If you examine the sample pictures in Amazon under the Canon EF 2X II Extender Telephoto Accessory, you will see the Shuttle Discovery taken with a Canon XT1, Canon 100-400mm, and the 2X at about 4 miles. This was without a tripod, through the shimmering heat of the Florida day, and with the salt air from a windy day causing a lot of haze. I could have just relied on the 100-400 at maximum and enlarged and cropped later. It was easier to frame the shot and know what you are getting through the view finder using the 2X. Yes, I use it with a Canon 100-400 and yes, you do have to manually focus the lens. I do not see this as a major problem. The Canon EF 2X II Extender Telephoto Accessory works exactly as described by Canon!

It is manual focus only! It did not mention clearly

I chose this version over the latest one for two reasons: price and the fact that none of my lenses are of the latest generation. After a quick test to ensure that everything was working correctly I can report that it works perfectly with a first generation 70-200mm L (non-IS). Focussing is still reasonably fast in bright conditions. Very happy.

Quello che cercavo per migliorare e potenziare i miei obiettivi

Great quality well-made

Very good easy to use