R5 lunar photography with stacked EF extenders

Bigger wrote:

There was some interest in Stacking RF extenders in an older thread that focused a lot on maximum focus distance. So, I thought I would start a new thread on stacking EF extenders on RF bodies for lunar (and planetary) photography.

Funny you should mention that.

FDn 500mm f/4.5 L + FD 1.4x (EF mod) + 7D Mk II

Admittedly that one was not with stacked extenders, but the next one is.

FDn 500mm f/4.5 L + FD 1.4x (EF mod) + RF 2x + RP

I suppose the focus is a bit behind on the second one. Having only Manfrotto 190 as tripod doesn't help either, but the worst problem is the FD 1.4x. Its performance is pretty far from the newer ones or the 500mm L.

Too bad I can't attach the RF extenders directly behind the FDn. The levers stick just a bit too far. It would require either cutting away the levers and filing some of the pins or having someone do the EF modification to the lens. The latter would allow stacking EF and RF extenders, which would be nice. For short distances a 12mm FD to EF adapter will do as well.