Jorge:(posted 8324 days ago)The lens is a Roddenstock Grandagon-N 75mm. I have noticed some falloff around the ledges, but never excessive density in the middle. I've taken a reasonable number of shots with the lens, and have not noticed this center density in all the shots.
James:
I run the tubes in a fairly narrow container, and so they don't have a lot of movement left-to-right. However, I'll try and make sure that the rotation is a bit 'smoother', and that I don't bounce the tubes up and down too much (which may cause the sloshing you mention).
Thanks!