Originally posted by mersault The problem comes when I am in manual mode where no changes in aperture or speed affect the histogram.
This behaviour isn't intuitive.
The LV live histogram reflects the histogram as is
currently captured by the sensor. The LV feed uses metering and EV compensation and AE-L.
LV stops the lens down but not necessarily to the exact same f-stop as the exposure when taken. And LV doesn't necessarily use the shutter time of the exposure. Actually, some shutter times like 1/8000s are impossible for the LV feed. So, the entire process is pretty complex. However, via exposure reciprocity, the live histogram
normally still reflects the actual exposure.
The important thing to understand is that the LV feed always uses automatic settings. Otherwise, you could open the lens long enough and wide enough to actually damage the sensor (remember the sun/loupe/paper experiment you did as a kid?). Think of a sun image focussed onto the focal plane ... (you could still do that in bulb; but not as easily)
The only "bug" is that the firmware doesn't apply a correction to the live histogram if the manual setting and metered exposure don't match via exposure reciprocity. The "work around" is to use EV compensation in manual to bring the over-/under-exposure scale to zero. This may sound awkward. But you can "dial" EV compensation in manual until you see fit in the live histogram. And then press the green button. And then work from there.