Canon 24 L MK II and Extension tube

I just finished reading a review of the 24 L MK II on" The Digital Picture.com" and I found it interesting that the reviewer mentioned using an extender on this lens. I've never dabbled in extenders before but, I only know that you can get closer to your subject. So, with that in mind, what kind of results do I expect if I use a 12mm extension? I appreciate any feedback. Thanks!

Here's a copy paste from that article:
The Canon EF 24mm f/1.4 L II USM Lens' numbers are not impressive, but not unusual for a wide angle prime lens. Since the zoom lenses draw upon their maximum focal length, they produce healthier Maximum Magnification numbers on the chart - but the zooms do not focus as close and therefore produce lower MM than the 24 L II at their 24mm settings. If you want to shoot as close as possible at 24mm, the primes will do the job best. Add a 12mm Extension Tube and the 24 L primes will focus to .82' (.25m) for a MM of .66x. A 24mm perspective at this magnification will be unique.

It's true that canon can't focus very closely ...
I was surprised when I made a small comparison with a sigma 24F1.8 DG
https://photography-on-the.net …24L1.4II+in+the​+real+Life

But, 25cm is not bat at all, I can take pictures in restaurants of my dishes quite easily . I own both canon extension tubes EF12 and EF25, but I never needed to use it with the 24L1.4II, I use them with my 135L2.0 and 85L1.2II.
With a 24l1.4II, you get the lens very near the subject and it becomes difficult not get a disturbing camera shadow. I suppose with a ring flash, it should be more usable, but not so easy to use in real life at least as a walkaround.

newworld666 wrote in post #10357260
It's true that canon can't focus very closely ...
I was surprised when I made a small comparison with a sigma 24F1.8 DG
https://photography-on-the.net …24L1.4II+in+the​+real+Life

But, 25cm is not bat at all, I can take pictures in restaurants of my dishes quite easily . I own both canon extension tubes EF12 and EF25, but I never needed to use it with the 24L1.4II, I use them with my 135L2.0 and 85L1.2II.
With a 24l1.4II, you get the lens very near the subject and it becomes difficult not get a disturbing camera shadow. I suppose with a ring flash, it should be more usable, but not so easy to use in real life at least as a walkaround.

Thanks for your reply. I read your comparison with the 24 L and Siggy quite interesting. As for the extension, I was just curious to find out what the benefits would be. Anyways, I'm so dying to try out my new 24 L II!

I tried the Canon 12mm ring on my 24LII, but didn't like the results. Because the lens has a curved focal plane (is that the right term in English?) only a small spot in the middle was sharp. I actually got better results with my old 24/2.8 which has a more straight focal plane (but is otherwise not as good as the L, of course). I love my 24LII, but can't recommend to use it with the extender. I also have a Canon 500D close-up filter, and that one works fine on the 24LII, but magnification isn't that much improved, so after have tested it I have only used the lens "bare".

Helena wrote in post #10360524
I tried the Canon 12mm ring on my 24LII, but didn't like the results. Because the lens has a curved focal plane (is that the right term in English?) only a small spot in the middle was sharp. I actually got better results with my old 24/2.8 which has a more straight focal plane (but is otherwise not as good as the L, of course). I love my 24LII, but can't recommend to use it with the extender. I also have a Canon 500D close-up filter, and that one works fine on the 24LII, but magnification isn't that much improved, so after have tested it I have only used the lens "bare".

Thanks for posting your experience Helena. That kills my curiousity with the extender and it's benefits. I guess using an extender will benefit using longer focal lengths.