topic RF 70-200 f2.8 Z w 2x teleconverter or EF 100-400 (mark 1) in Gear Guide

RF 70-200 f2.8 Z w 2x teleconverter or EF 100-400 (mark 1)

ian-s — Mon, 19 May 2025 17:39:22 GMT

Hello! I am a long-time birdwatcher, new bird photographer, looking forward to some upcoming summer trips. My kit currently consists of a Canon R6 and the original EF 100-400 with an RF adapter.

I’m planning on adding the new RF70-200 f2.8 Z lens to my kit before the summer and I’m wondering if I get the 2x teleconverter could I safely leave my old EF100-400 behind? The focal length and minimum aperture would be equivalent, and it seems like I shouldn’t lose focusing speed etc. since the new RF lens should be faster than the old EF lens.

Thoughts? The weight savings would be huge if I could get away with it.

Re: RF 70-200 f2.8 Z w 2x teleconverter or EF 100-400 (mark 1)

JFG — Fri, 23 May 2025 06:31:02 GMT

Hi ian-s,

The RF native lens works better on an R6 than an EF lens for the following reasons:

Autofocus performance: RF lenses have faster, more precise autofocus, especially with face and eye tracking.

Optical Quality: RF lenses are optimized for mirrorless cameras, offering better sharpness, contrast, and stabilization.

Size & Weight: RF lenses are more compact since they don't need space for a DSLR mirror.

However, using the RF70-200mm f2.8 L IS USM Z with a 2x converter slightly reduces sharpness and contrast, but RF lenses handle it well. Autofocus speed; the 2x converter can slow down autofocus, especially in low light. The RF lens is more compact than carrying a dedicated EF100-400 lens with an EF-RF adapter.

I hope this helps. Let us know what you decide.

Re: RF 70-200 f2.8 Z w 2x teleconverter or EF 100-400 (mark 1)

p4pictures — Sat, 24 May 2025 12:46:12 GMT

I'm in agreement with Joe, I think you should go with the RF 70-200mm f/2.8 Z and use the RF 2x extender. This combination will be be sharper than the original EF 100-400mm and will allow your EOS R6 camera to shoot at a faster frame rate since the old version of the EF 100-400mm automatically limits the continuous shooting speed as the lens cannot communicate fast enough with the camera. Additionally the AF performance of the RF lens and extender combination is much improved over the EF 100-400mm lens you have.

Re: RF 70-200 f2.8 Z w 2x teleconverter or EF 100-400 (mark 1)

shadowsports — Sat, 24 May 2025 13:04:00 GMT

Greetings ,

Additionally, the RF lens will serve you better in the long run as it will move forward with you seamlessly when you decide to get your next body.