EOS R100 and Extender RF2x compatibility

[JENDUPLANTIS]

I'm just a little confused. I have a beginner Canon EOS R100 and have purchased a new lens 100-400 and works fine. I first started with a used 75-300 EF mount with an adapter, then purchased used EF teleconverter so I got 150-600. I wanted to change everything to all RF mount lenses so I purchased the RF mount 100-400 lens. I was a little upset that the extender 2.0 was so expensive (more than the 100-400 lens that I purchased). I made sure the 100-400 lens was compatible with the rf 2x extender but now I've read somewhere the extender is not compatible with my camera EOS R100. It fits fine on my camera but I just want to make sure I'm not messing the camera up. I do want to eventually purchase a nicer camera (EOS R7). This bird watching hobby I started is quite expensive. Is it ok to use the extender on my camera without messing it up? I don't understand how it could not be compatible if it goes right on my camera no problem

[deebatman316]

Yes it’s Digic processor it uses. It uses the Digic 8 processor found in many older high end DSLR cameras. Most EOS R series cameras use Digic X processors. Also the camera fps in stills mode is very low. It’s only capable of 6 fps in One Shot AF then in Servo AF only 3-4 fps. I don’t think this camera is fast enough to support simultaneous AF & Aperture control. A lot of older Arc Form Drive (AFD) EF lenses released between 1987-1990. Don’t support this either due to physical hardware limitations. The communication speed between the body and lens are just too slow. Micro Motor and USM lenses never had this issue from there beginning. They can drive both aperture and AF at the same time. Ring Type USM was first released in 1987. It is also one of the oldest AF motors still in production today. The only drawback to those older lenses. Is that they were focus-by-wire. So if the AF motor were to fail the lens became a paper weight. The last ever produced AFD lens was the EF 50mm F/2.5 Compact Macro lens. It was released in December of 1987 and discontinued a couple years ago. 

[ebiggs1]

If I were you I would avoid tele converters all together. A lens like the Canon RF 200-800mm f/6.3-9 IS USM Lens is a far better choice.

[JENDUPLANTIS]

I would love that if money was not an obstacle, lol. My next purchase will be a new camera for almost $1000 less than that lens.