>>3199102I might mention that the EXIF data doesn't show the use of an Extender in the resulting data... because the EF-12 tele-extender module fools the camera into allowing the use of two extenders simultaneously.
Canon does not recommend using two Extenders together. They claim that it can affect the function of the camera, resulting in errors for focus and exposure. Hence the new series-III extenders are not designed to fit together physically either. Cheating with a tele-extender (EF-12) enables you to bypass the physical problem by sneaking this "spacer" between the two Extenders... although the resulting EXIF data is also then devoid of one of the Extenders.
But, as you can see... it still works. And the results are as good or better than the camera-to-scope results I got earlier. Most of the lunar shots I took above were taken handheld too - because the new-Gen Image Stabilizer on the 100-400mmL II lens is so effective.