EV differences in Manual vs Auto

[leecow]

This was an interesting discovery.



Same settings chosen in Manual as are reported by the Auto Exposure mode but where Auto shows 0.0 EV, manual (correctly it seems to me as well as the histogram) shows -1.3 EV.

Lee

 

[sonof40]

Interesting. I hope someone can expand on this.

OT: Can you explain how you got those images and then got them into your post?

 

[leecow]

@sono40 - screenshot from the iPad then cropped down and added annotations on the PC.

 

[Randy_Culp]

You can see how EV works in Auto mode if you turn on Video Caption, then record while making changes to EV in auto mode or changing ISO/Shutter in manual mode. Give each change a few seconds to settle. What I noticed is that in manual mode, an ISO setting of 800 is 800. In auto mode however... you can get lots of in-between values like 475 or 508 that are actually set but what is *displayed* is ONLY one of the selectable ISO values - 400, 800, 1600, etc. The display simply rounds a value like 463 to 400. So the reason Auto shows 0.0 EV, and manual shows -1.3 EV in your example above is quite simply because the Mavic is cheating. The ISO in Auto is not really 1600, but probably something more like 1800 and change. It's an easy test to run, I recommend it.

 

[RavenTBK]

You can see how EV works in Auto mode if you turn on Video Caption, then record while making changes to EV in auto mode or changing ISO/Shutter in manual mode. Give each change a few seconds to settle. What I noticed is that in manual mode, an ISO setting of 800 is 800. In auto mode however... you can get lots of in-between values like 475 or 508 that are actually set but what is *displayed* is ONLY one of the selectable ISO values - 400, 800, 1600, etc. The display simply rounds a value like 463 to 400. So the reason Auto shows 0.0 EV, and manual shows -1.3 EV in your example above is quite simply because the Mavic is cheating. The ISO in Auto is not really 1600, but probably something more like 1800 and change. It's an easy test to run, I recommend it.

That makes sense.

 

[Kilrah]

When you're in Auto mode the EV is an exposure compensation setting (as can be seen by the blue color), the 0.0 tells you you didn't apply an exposure bias. When you're in manual it's an exposure indication of the current scene brightness and the -1.3 tells you that with the current settings the scene is underexposed. Nothing in common per se.

Just like pretty much every other camera out there.