Originally posted by mrpackerguy Not to de-rail my own thread, but how do you get the histogram off the LCD display after shooting a picture?
I have made my own process for checking exposure accuracy not only of the bodies but lenses. (again it is described earlier in the thread but I will repeat it here for simplicity)
I select a uniformly lit and colored surface. Usually this is a paved road, sidewalk or concrete wall.
I then shoot a shot at every apature click on the lens, metering with the green button, to set shutter speed. I use 1/2 stop increments for shutter speed because this is what the detents on a manual apature lens are.
once I have taken the series of shots, I put them into PSP X2 (any photo editor will do) and measure the greyscale value for the center 10% of the frame.
It is that value that I plotted against Apature, with apature on a log scale, so that each stop is an equal distance.
I have done similar tests keeping shutter constant and changing apature both sides of the middle stop to check the dynamic range of the sensor and camera also. this is how I know that with neutral contrast, in the middle of the range each stop is 45 greyscale. (max contrast each stop is 50, min contrast each stop is 40)