Out of focus issue on Mamiya RZ67

[picturesfromthelow]

Hello everybody,
I recently bought a Mamiya RZ67 Pro II, together with two lenses, the 90mm f3.5W and the M65mm f4 L-A (the one with floating elemnt). I carried it with me on a trip to Hong Kong. I am now checking the scanned negatives and see that, especially in the vertical shots, the photos taken with the 65mm lens seem to be out of focus in the upper portion of the frame. I'm attaching an example. Can it be a problem with lens? If i remember correctly this shot was focused at infinity and the floating element was set accordingly to infinity. The shots taken with the 90mm lens do not seem to be affected.
Luca

[Rod.Klukas]

What aperture did you shoot at?

Wide open this could occur.  Wider angle lenses should be stopped down about 3 stops for best quality, due to curvature of field.

The 90mm is best at at least 2 stops down.

This also pertains to most Large format lenses as well.

Try again and also check the lens is stopping down.

Hope this helps.

Rod