Canon EXT. RF1.4X(N) (4113C002)

I've used this extender on my R5 with both my 100-500mm and 800mm lenses and it works extremely well. It does add one F-stop but that has been a small price to pay for the extra reach as I photograph wildlife and getting close can be tricky. I have noticed that the auto focusing (particularly eye detection) can be fractionally slower when I use the extender than just using the native lens, but it hasn't been significant enough for me to abandon the idea of using it for the extra reach. Thankfully, the R5 can handle high ISO rates well enough that the loss of the F-stop hasn't stopped me from getting decent photos. In fact, the photos are limited only by my own lack of expertise.It is a very useful addition for squeezing a little extra reach out of my lenses for capturing wildlife in the field. I included two photos I took using the R5 + extender with my 100-500mm telephoto, giving me 700mm for these shots. While I'm not a great photographer, they do give you a feel for what is possible.One note: to install the extender, your compatible lens needs to be fully extended. For example, when I used the 1.4X extender with my 100-500mm Canon RF lens, the lens was fully extended to 500mm before I installed the extender. Until the lens is fully extended, you cannot install the extender. Now, I can inch the lens down to about 450mm but with the extender installed, you're basically "committed" to using the lens at the full reach, which in my case was the full 500mm, giving me 700mm with the two components. If that makes sense.

Highly Recommend if you need some extra reach. If you know how to use your settings you can retain really good picture quality. Definitely keeping this for when I need some extra reach.

Despite the Canon name (and price) I expected a slight loss of quality. I've experienced none, not on a 100-400, not on the 200-800. You do lose an f stop, but with how well the R6ii handles an ISO bump, not an issue at all. Excellent product.

The RF 1.4x extender is an excellent product all around, except that it is quite expensive. I paired it to a Canon RF 100-500mm lens, and everything workers well with, so I can't complain about its performance, including IQ, focusing, and the rest.Be aware that if any of two extenders (1.4x, and 2x) are used with the RF 100-500mm or any other zoom lens like this, the lens can only be zoomed from 300mm to 500mm. Then if you want to zoom back retract the lens to 100mm, for example, that is not possible since the lens cannot be retracted past 300mm (can be extended/retracted only between 300 and 500mm).This 1.4x (or 2x) extender should be just about perfect for using with prime lenses, not zooms such as the RF 100-500mm unless you are photographing under bright daylight. With this lens at 500mm its aperture is around f/7.1 without the extender. The You should lose around 1 "f" stop by adding the 1.4x extender alone. But it should be about perfect with a RF prime.

I paired this with my Canon R 10 and RF 100 - 400 lens. That makes it a 140 -560 lens. It works well, with good sharp images. It works through the full range of the 100 - 400. You do lose a full F stop. And the auto focus is not quite as fast. But I am very pleased.

Works great. Came packaged well and works nicely with my 100 to 500

Am so glad the Canon teleconverter 1.4 fits my R50 like a glove, as well as my Canon 100-400 lens. No adapter needed. There was no loss of sharpness as evidenced by the unedited pine tree pic. I highly recommend this teleconverter!

Unlike the 2x TC III, this 1.4x delivers! No noticeable loss of sharpness and no focus lag. Used with two Canon lenses, the EF f/4 400MM DO and the 500MM f/4 III. Expensive but really good.