The-Digital-Picture hacks EF-RF adapter to make *all* EF lenses work with RF teleconverters

[scyrene]

I used to stack EF teleconverters. The most I ever managed was 5600mm I think (500x1.4x2x2x2). I was able to resolve features on the disc of Mars that way.

 

[kaihp]

Commlite.

RF and EF extenders on the EF 600/4L IS II

After getting both the RF extenders to use with my RF 100-500L, I became curious about whether they would perform better than my EF MkIII extenders when used with my EF 600/4L IS II on my EOS R3. As most will know, the protruding elements of the RF extenders do not fit into the Canon EF-RF mount...

www.canonrumors.com

I modifed the Commlite, and took out significantly less than what you did. Posting here so other can see what is needed. I opted for a mechanical file and a sharp knife (break-off blade type) to modify it.

I was concerned that the PCB had some delicate functionality in it, but as far as I can tell know, the answer is no. You need to go a bit under the height of the PCB to clear the extender sufficiently. Pictures 1 & 2 should with the 2x extender inserted into the Commlite RF adapter.

 

[kaihp]

Neuro and others that are stacking RF and EF extenders: only the RF extender registers when I stack a RF 2x and an EF 2x Mk III on the EF 200-400. Are you seeing the same with your lenses?

Been shooting the moon again this evening and instead of saying 1600mm f/16 the R3 thinks it's a 800mm f/8 combo.
Clicking in the built-in 1.4x extender makes it clock out at 2240mm f/22 and the moon fills out almost the full height of the sensor. This makes it hard to track the moon as it moves damn fast suddenly and I need to readjust the gimbal head all the time

 

[neuroanatomist]

Neuro and others that are stacking RF and EF extenders: only the RF extender registers when I stack a RF 2x and an EF 2x Mk III on the EF 200-400. Are you seeing the same with your lenses?

Yes, only one TC registers.

 

[meywd]

Yup only one is recorded.

 

[YeeEeEty]

Used Lightroom super res instead of Topaz


100-400 Super Res

100-400 Pure (400mm f5.6)

100-400 IS II + EF 2x III (800mm f11)

100-400 IS II + EF 2x III + EF 2x II (1600mm f22)

100-400 IS II + EF 2x III + EF 2x II + EF 1.4 III (2240mm f/32)

Full and crop images can be seen in Album

+2

100-400 IS II + EF 2x III + EF 2x II + EF 1.4 III Tests

• meywd
• Nov 4, 2024
• 11

how did you stack all of EF 2x III + EF 2x II + EF 1.4 III? I heard only EF 2x II have enough space on the back side to accommodate the protruding part of the other extenders, did you use an extension tube in between two of them?

 

[meywd]

how did you stack all of EF 2x III + EF 2x II + EF 1.4 III? I heard only EF 2x II have enough space on the back side to accommodate the protruding part of the other extenders, did you use an extension tube in between two of them?

Yes the smallest one from Canon