vignetting

[luc]

i am using a master linh.tech. with a new apo-symmar 180/5.6

since using this lens i am noticing a very small vignetting on the four corner of the chromes. please note that the pictures was taken with no swing,tilt or any other movement . the subjects are beetween 3ft and 8ft. the films holders are several differents new lisco. could any one help me to find what cause this problem?

many thanks. luc

[Mike Long]

That lens has plenty of coverage for 4x5. Are you using a filter holder or a len s shade that extends too far? Are you stopping down? (I don't know the coverage at F5.6 but it would be less than at the standard specification aperture of F22) .

Mike