Hi, i use fp4+ on 4x5 (landscapes and fineart) and when using times of +1 second i add time for the reprocity failure. But my feeling when i look at the negs afterwards is that it is not that high as mentioned on paper. Yesterday i did a test with a fuji acros, shot it at 8 seconds, took a fp4+ and shot it also at 8 secs. After development the density of the gray background looks the same ( i tried rodinal and pyrocat HD). ilford says when 8 seconds is found by the meter, use 25 seconds instead. that is 1.5 stop overexposed. So my ilford neg should be 1.5 stops underexposed, but the shadow details are the same on both negs.... What I do is I use a digital spotmeter and gray card to get the right time in my fine-art studio. the light I use is daylight. Is the reprocity failure a phantasy story when you use a proper exposure and development????