Thanks Akira, yes since my camera also was leveled by eye, now we can measure and calculate the difference in latitudes on the condition that both images were fresh takes (as the moon wobbles over time). BTW I used the 300PF+TC14E+TC20E III on D500 for this take.
Thanks Øivind for sharing the details of your setup, I didn't think it was possible to use the two TCs together!
Upon a second look, I found out that I could couple them, using the TC20E III attached to the lens, followed by the TC-14E II (close to the body). Naturally both had been modified by removing the blocking flange on the mount that prevented it.
If I were to use both teleconverters on my 1V3 I would have to resort to tiling 4 pictures together, the moon fills the frame already with a 500mm + TC20E. Here's an example taken yesterday with this setup:
Nikon 1V3 + FT1 + TC20EIII + 200-500mm @450mm (I had to lower the zoom for easier framing, @500mm a small slice of the moon is excluded if framing is not 100% perfect)
I added a few black pixels top and bottom, and cropped the sides to have a square photo. 3500x3500 px, resized to 1200x1200. Original uncropped is 5232x3488 px.
Ciao from Massimo
My latitude is 44.494810° N, between Akira's and yours.