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.

Call me greedy but my RF 100-500 comes up a tad short sometimes. Missed shots because, even with cropping, I'm just a tad short. While I love my R5, native lens options are still in their infancy, so what's a guy to do? The only option is either suffer, buy a non-native lens and adapter, or live with the 1.4x or 2.0x RF extenders. I chose the latter.Before I go further, please know the RF extenders only work in a handful of RF lens, The RF 600, 800, and 100-500. They won't work in any other lens out right now (July 2021). So if that's not you, you can stop reading here.Before I bought the RF 1.4x I rented the 2.0x, because, hey for $100 more I could get 1000mm reach instead of 700mm. The 2.0x is really nice, but it didn't suit my style of run and gun photography. I see a picture I take it, I don't sit in a blind for hours waiting for something to happen. Because the RF extenders are an odd-duck on the 100-500 and must be attached with the lens at 300mm (which will become 2.0x) I can't get a good handle on my surroundings at 600mm. I need to zoom out a little and then zoom back in. So that was out.The 1.4x, for me, is easer to handle on the move. It converts my 100-500 lens to a 420-700mm lens which is great for shooting birds in flight or even perched birds or bison, or bears where, again 500mm is just a tad short because of the distance between you and the animal. But I've also used it at zoos and it makes for great animal portraits. Their is really no perceptable loss of sharpness, something I can't say when you put on some junky filters or even old school extenders. But there is a penalty to be paid (other than $). You lose a stop of light, which is a lot for an already slow-ish lens. Focusing is **almost** 100% of the len's capability. It's just a hair slower -- something you noticed but doesn't really affect the outcome.So my dislikes about the RF 1.4x extender, which I knew going in: 1) on the RF100-500 you are robbed of "wider" angles since it's locked into the 300mm length. So you lose some of the lenses versatility there. And because of how extender is installed in the lens, it's a bit of work to remove it, and not something you'll want do do in the field unless you have a clean, stable platform to do so. So, for me, once it's on, it's on for that shoot. That means you have to really know before you go on a shoot what you intend to be shooting.2) At $400, it's a lot of money for a 200mm gain. It had me doing a lot of thinking when I could sacrifice some MPs and crop to simulate. But ultmately, I wanted the full 45mp details of that actual tight shot of the proud eagle, lunch in talons. That's worth $400 divided by all the cool pics I hope to get with it.

I use the extender on my RF 100-500 lens. It gives me 700mm at full extension. There is little or no degradation in picture quality. The down side is that the lens is limited to 300mm and above. There is a physical block to restrict using the lens below the 300mm mark. This is of course due to the physical characteristics of the lens and adapter with a full frame sensor. I keep the extender on my RF100-500 about 60% of the time. The Bluebird pic was taken on an EOR R6 1/12000, F10, 700mm, ISO 800. Distance of about 60 feet. This is straight out of camera with no post.

I dont know why but no one has mentioned that the ONLY RF zoom that this TC works with 100% is the RF 100-400 at this time. If I think I may need more than 400 I put the RF 1.4x on the RF 100-400 before I leave the house.

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.