Canon EF 1.4X III Telephoto Extender for Canon Super Telephoto Lenses

LOVE this Extender EF 1.4x III - The photos have been amazing!

The Extender EF 1.4x, the 3rd generation has excellent optics and produces impressive images (So does its 2x sibling). The purpose for using this extender to enlarge the subject matter in the image frame. Not to reach long distances. Atmospheric interference means any haziness, or heat haze will only be magnified. This extender was designed for L lenses. It works superbly with the prime lenses. I have used it with the 300mm f/2.8 ver II, 500mm f/2.8 ver II as well as the 600mm f/4 ver II. In addition, I have used this extender with the EF 100-400mm ver II. The images this combo produces is amazing considering it is not a prime lens. If your goal is to extend your reach so you can take pictures of distant subjects and expect a clear and sharp image, you will be disappointed. Even a prime lens with the extended reach will have difficulty producing a clear image due to atmospheric conditions. However, if you are taking pictures of subjects such as birds, or aircraft that fit 1/2 of the frame and wish to have images that fill 3/4 or more of a frame at distances that are not effected by atmospheric conditions, then you will amazed by the results this combination provides. Note: on a zoom lens such as the 100-400mm ver II, your f stop will become f/8 and therefore you will only be able to use a small portion of the autofocus points and in lower models perhaps manual focus will be your only choice. This is where a mirrorless camera is the perfect solution as it will allow for use of all autofocus points. Also, because of the additional reach, you will need to increase your shutter speed and expect slower autofocus acquisition in low light. This is an excellent addition to ones photography tools, but needs to be used in appropriate conditions.

It appears to not be sharp at least at 4.0, 4.5, 5.0 and low apertures. Not surprised as I have had a few 1.4x extenders that have also proven to not be sharp. Very annoying...It may get sent back after I run a few more tests.

When used with the EOS Rebel T2i body, the autofocus won't function. Your only choice is manual focus. It also will not fit onto Zoom Lens EF 75-300mm 1:4-5.6 III. But it works wonderfully with Zoom Lens EF 100-400mm 1:4.5-5.6 L IS II USM.

The distortion at long range is more than I thought it would be.

Works great when paired with my 100-400mm and 80d!

I resisted buying one because of not so hot reviews. Then I learned that pros use them and attribute problems to user error. So, I bought one. I use it mainly for shooting birds with a 5D IV and 100-400 IS II. I have also used it with a 77D. Bear in mind the longer focal length will require a steadier hold and/or higher shutter speed. Autofocus can struggle in low contrast situations. My results improved when I practiced steady holds. The photo below was shot at f/11 & 1/500 handheld. It's also been cropped at least 80%.

this extender did not work with my rebel t6i, my disappointed

Love it. It has greatly enhanced my wildlife photography

Auto focus will not work with Canon 70D and Canon100-400 f.4-f.56 - f stop loss is too much for it to handle. Would have been nice to know requirements before purchase. I have returned for refund.

I purchased this extender to use with my EF 70-200mm f 4 L USM which I use with a Canon EOS T5i 700D. I would have given 5 stars however nothing is perfect. My primary use is for nature photography. I have had no problems with autofocus or sharpness.

While there's much flack about the sharpness of extenders, even the EF 1.4x III, I'd say they were right. But wait!! I saw the same issue when attaching this extender to my 70-200 2.8 L II—slightly back focused on my 1DX2. The fix is to make AF microadjustments on the camera body to calibrate for AF focus. After fine tuning the adjustments, now razor sharp on both W-T and the AF servo focus is fast. Totally surprised how many photographers are unaware of this critical and necessary AF microadjustment. However, be forewarned, camera menu AF microadjustments are typically not available on Canon consumer type DSLRs. The weather sealing is great, and guess what? This teleconverter also works on my 120-300mm 2.8 zoom too.

I do not recommend this extender as it impacts sharpness. In numerous tests, this extender reduced the sharpness of my EF 70-200mm f/2.8L IS II USM from what I would describe as tack-sharp to "soft". There is no sense in having a 1.4 boost in focal length if the picture is not sharp.

I love the product, but canonusa.com registration process does not even allow the user to view the serial number and purchase date information that one previously entered. This is very frustrating when doing things like providing information for insurance coverage or opening a support ticket. Fix the registration process, and I'll rate on just the product and raise it up a lot.