I only do 4 sheets of 8x10 at a time in an oversize tray. Have to be very careful not do get any
surge marks on this kind of subtle very low contrast work. Two problems with exposure. You have
to balance the mask for the depressed green sensitivity of the FP4 pan film, and you have to null
out the effect of the orange mask. After considerable testing what works best for me is to balance
the color head to 5000K or thereabouts using a color temp meter, then add a light YG filter (Hoya
XO) to cure the pan effect, then a pale orange (G) to "see through" the mask density. But color
balance can change with recip effects, so I aim for about a 10 sec exp under the enlarger in the
contact frame.