ALL CAPS BECAUSE THIS IMPORTANT. A 150 used a 6" lens cone. A 135 a 3 1/2 . IF YOU PUT A 135 ON THE 6", YOU WILL NOT BE ABLE TO MAKE LARGE PRINTS.

BECAUSE IT IS TOO FAR FROM THE NEGATIVE.

IF YOU PUT A 150 ON A SMALL CONE , THEN YOU CAN NOT MAKE SMALL PRINTS.

SO MATCH THE CONE YOU HAVE.

A 150 cover 4x5 "better". 135 was for 3.25 x 3.75 " negs.