With a Canon 100mm f2.8 macro lens attached to a Canon 6D camera (firmware 1.1.8 installed) on a tripod I was experimenting with 1.1 magnifications with TTL meter readings and I noted the following observations:
Between f2.8 and f5 on Manual mode (M) and selected ISO value (rather than Auto ISO) the live view image on the LCD screen and accompanying histogram were about 2 stops underexposed when compared with the mid-centered exposure level indicator and final captured image. Refer to attached images 1 (live view) and 2 (captured view) . The difference between the two images and histograms is quite remarkable. Changing ISO values made no difference. Beyond f5 aperture readings, the before and after images including histograms all coincided and compatibility resumed.
The anomaly disappeared while repeating the same above exercise with Auto ISO, even though the auto value was the same as the selected one above. Live view images, histogram profiles and final captured images were all perfectly equal and compatible. No problems at all. Refer to attached images 3 (live view) and 4 (captured view).
The anomaly also didn't exist when using the same parameters in TV, Av and P modes, again perfect before and after images and exposures, regardless of selected or Auto ISO values.
To further clarify matters, exposure simulation was always enabled and exposure sim warning flashes did not occur. Metering modes had no influence on the results. The subject was a small two dimensional print, mostly of mid-tones, and depth of field was unimportant.
So using Manual mode with non-Auto ISO values with apertures between f2.8 and f5 at close focus distances reveals discrepancies between live view exposures and final taken images. All other potential exposure parameters and modes did not reveal the same resulting discrepancy.
My query is more academic than practical. I have never come across this before because my exposure setting and procedures have never taken me to this extreme application. It is an interesting one, never the less, brought about through experimentation rather than anything else. It does raise some interesting questions as to why this is happening.
There appears to be a live view, captured image compatibly problem only in manual mode with small f numbers, which may only apply to macro lenses at close focus distances. The problem could rest with my equipment alone, or may be a more global anomaly.
Has anyone come across this oddity before?
Between f2.8 and f5 on Manual mode (M) and selected ISO value (rather than Auto ISO) the live view image on the LCD screen and accompanying histogram were about 2 stops underexposed when compared with the mid-centered exposure level indicator and final captured image. Refer to attached images 1 (live view) and 2 (captured view) . The difference between the two images and histograms is quite remarkable. Changing ISO values made no difference. Beyond f5 aperture readings, the before and after images including histograms all coincided and compatibility resumed.
The anomaly disappeared while repeating the same above exercise with Auto ISO, even though the auto value was the same as the selected one above. Live view images, histogram profiles and final captured images were all perfectly equal and compatible. No problems at all. Refer to attached images 3 (live view) and 4 (captured view).
The anomaly also didn't exist when using the same parameters in TV, Av and P modes, again perfect before and after images and exposures, regardless of selected or Auto ISO values.
To further clarify matters, exposure simulation was always enabled and exposure sim warning flashes did not occur. Metering modes had no influence on the results. The subject was a small two dimensional print, mostly of mid-tones, and depth of field was unimportant.
So using Manual mode with non-Auto ISO values with apertures between f2.8 and f5 at close focus distances reveals discrepancies between live view exposures and final taken images. All other potential exposure parameters and modes did not reveal the same resulting discrepancy.
My query is more academic than practical. I have never come across this before because my exposure setting and procedures have never taken me to this extreme application. It is an interesting one, never the less, brought about through experimentation rather than anything else. It does raise some interesting questions as to why this is happening.
There appears to be a live view, captured image compatibly problem only in manual mode with small f numbers, which may only apply to macro lenses at close focus distances. The problem could rest with my equipment alone, or may be a more global anomaly.
Has anyone come across this oddity before?
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