R5 lunar photography with stacked EF extenders

Yesterday I took the first few pictures of the Moon with the R5 and EF 600mm f/4 II on a tripod. Only single shots, no image stacking. The first picture is with the 2x iii extender (1200mm). I must say I’m quite impressed by the result. The second picture is with a stack of two 2x extenders (2x ii plus 2x iii, 2400mm). The sharpness impression of the latter is less but I believe it has at least the same amount of detail. For a good comparison the scales of both images have to be the equalized. Whether the double stack can bring more details is still uncertain based on these results. Of course all is very critical at 2400mm like vibrations, focus and seeing conditions. It was very cold outside and the equipment for sure was not adapted to the outside temperature after being outside for only a few minutes.
So I do expect to be able to improve the double stack result but it is doubtful if it can beat the single 2x extender with respect to resolution. For sure a few more test will follow.

I took a few short videos in 8K for some image stacking testing (workflow). For serious testing my tracking mount has to be used since the moon moves fast through the FOV.

BTW, these first 8K videos will not play in Canon’s own DPP4 whereas 4K videos (both made with the R5) do !!? Any ideas?

2x iii extender

stacked 2x ii and 2x iii