What exactly does EV change when in manual/pro mode?

[bvalente]

Hi everyone

I'm just looking for clarification on what exactly does the EV do when in manual/pro mode on the Air2S?

i have a fixed aperture and fixed shutter and fixed ISO, but i can cleary see the image getting brighter and darker as i adjust EV up or down respectively.

Thanks

Brian

 

[MS Coast]

Hi everyone

I'm just looking for clarification on what exactly does the EV do when in manual/pro mode on the Air2S?

i have a fixed aperture and fixed shutter and fixed ISO, but i can cleary see the image getting brighter and darker as i adjust EV up or down respectively.

Thanks

Brian

The EV adjustment just tells the camera to adjust the exposure up or down from what the settings are.

+1 EV adds one stop of exposure, making the image brighter. You could do the same by cutting the shutter speed in half, e.g. changing from 1/100 to 1/50, or by doubling the ISO, e.g. changing from 100 to 200.

 

[bvalente]

The EV adjustment just tells the camera to adjust the exposure up or down from what the settings are.

+1 EV adds one stop of exposure, making the image brighter. You could do the same by cutting the shutter speed in half, e.g. changing from 1/100 to 1/50, or by doubling the ISO, e.g. changing from 100 to 200.

Right i got that, but how does it do that?

does it increase iso? change shutter speed?

not sure, because i don't see any of those values changing on the screen

Thanks again

Brian

 

[MS Coast]

Right i got that, but how does it do that?

does it increase iso? change shutter speed?

not sure, because i don't see any of those values changing on the screen

Thanks again

Brian

Aha. Got it. That is a good question and I'd never thought about it before.

With the Air 2S, it would have tweak either ISO or shutter speed. The EXIF information for the image has the settings listed. I'll check the camera settings next time I'm flying and compare to the EXIF info.

We're having bad weather for the next couple of days. In the meantime, I can see what the conventional cameras do.

 

[Meta4]

We're having bad weather for the next couple of days. In the meantime, I can see what the conventional cameras do.

No need to fly to test.
You can shoot some test shots with the drone grounded on your desk or around the house.
The exif info will show what's happening.

 

[Niku]

EV (Exposure value). The exposure compensation is the same as saying to the camera, “Could you make this scene a little brighter? Thank you".

 

[Dave Maine]

On my P4 adv and MA, it holds the ISO constant and varies the shutter speed. This is what is most useful, as varying the ISO will change the overall image quality.

 

[EpicFlight]

On my P4 adv and MA, it holds the ISO constant and varies the shutter speed. This is what is most useful, as varying the ISO will change the overall image quality.

Watching this discussion with great curiosity...

Simple explanation, increasing EV means more light during the exposure, and the shutter explanation makes sense – in auto. The OP was asking about manual.

Don't have an answer without experiment.

However, on my Samsung Galaxy Fold 2 camera if I fix both shutter speed and iso EV adjustment grays out and becomes unavailable.

With both settings auto while using the "pro" (manual) camera, shutter and ISO can both be set to auto, and in this case changing EV causes ISO to change. Fix ISO and shutter speed changes with EV changes.

This is exactly how I would expect these settings to behave... it's the only possibility. I'll bet our drone cameras do the same thing.

 

[MS Coast]

There's some confusion here. Is it mine?

On my system, the EV control is not available in Auto mode. There's the MM value, but that's not an input, just an indication of how the manual exposure compares to what would be the auto value.

Air 2S, Galaxy S5 Android tablet, DJI Fly 1.5.9

 

[Roamer105]

With the FLY app, you can enable "subtitles". This causes the drone to report incremental shooting and location information. When you enable Auto you can see what settings changes as you go through changes in brightness. You will need to copy both the MOV and the SRT files into a common directory and play it with VLC Media Player (however it will NOT play video above 4K). That player will insert the subtitles while playing the video. A typical day shoot demonstrates a steady ISO but shutter speed or EV changes.

 

[BrianA]

Hi everyone

I'm just looking for clarification on what exactly does the EV do when in manual/pro mode on the Air2S?

i have a fixed aperture and fixed shutter and fixed ISO, but i can cleary see the image getting brighter and darker as i adjust EV up or down respectively.

Thanks

Brian

I don't know if this will answer your question, but, this a fairly good explanation as to what is going on. I've been into photography for about 40 years and I'm not exactly sure of this value either, although, I do understand the math and principle behind it. I started photography will an all manual camera and took a LOT of photos with a LOT of experimenting. I think a lot of the abilities and concepts have been lost since photography came into the digital world. The vast majority of folks shoot either in semi-auto or full auto and don't really worry about exposure or anything like that. I admit that I am now one of those and should get back into full manual mode to get better at my hobby. I also think that the ACTUAL exposure settings might be different than what is recorded in the EXIF data if EV is set to anything other than 0. This is just pure speculation but I haven't really looked at the EXIF data on photos that I changed EV. I usually correct any exposure and other things in post processing since I shoot in RAW format. Anyway, here is a brief explanation to your question.

"However, to solve this problem in automatic modes, there’s another tool incorporated into digital cameras called exposure compensation.

This tool corrects the zero value from our light meter by moving the natural zero of our light meter to the right or left, so that the camera doesn’t try to balance to an exposure value of zero. Instead, it balances to an exposure value that is more overexposed or underexposed than the initially estimated value.


A good example of this is when we try to photograph a snowy landscape in automatic mode. The camera will generally underexpose the image because the light meter finds too much white in the scene.


In that case, you can set the exposure compensation to +1 or +2 to add one or two more exposure stops to the final image. That way, the camera will calculate the correct exposure by adding one or two more stops of light, compared to what it had initially considered as its initial zero value."

Full article: What is exposure? Exposure in photography explained

 

[Meta4]

I also think that the ACTUAL exposure settings might be different than what is recorded in the EXIF data if EV is set to anything other than 0. This is just pure speculation but I haven't really looked at the EXIF data on photos that I changed EV

The image metadata records the actual exposure settings as well as whatever exposure compensation is used.
Here's an example of just part of the metadata with the relevant parts highlighted.

 

[BrianA]

The image metadata records the actual exposure settings as well as whatever exposure compensation is used.
Here's an example of just part of the metadata with the relevant parts highlighted.
View attachment 144213

Just curious. Were those settings all set in manual mode? Or was the EV a calculated value based on the shutter speed and aperture?

 

[Meta4]

Just curious. Were those settings all set in manual mode? Or was the EV a calculated value based on the shutter speed and aperture?

That shot was done with Aperture Priority, where I set the ISO and aperture and the camera selects what it thinks would be the appropriate shutter speed for correct exposure.
It was one of a bracket of 3 shots using AEB to offset exposure by 0.7 stops under and over the original shot.
To complicate things, I set exposure compensation to EV -0.7 to have the best chance of preventing the small bright white subject from burning out against the larger darker area around it in harsh light conditions.
Here are thumbnails for the three bracketed shots with their exposure data.

 

[BrianA]

That shot was done with Aperture Priority, where I set the ISO and aperture and the camera selects what it thinks would be the appropriate shutter speed for correct exposure.
It was one of a bracket of 3 shots using AEB to offset exposure by 0.7 stops under and over the original shot.
To complicate things, I set exposure compensation to EV -0.7 to have the best chance of preventing the small bright white subject from burning out against the larger darker area around it in harsh light conditions.
Here are thumbnails for the three bracketed shots with their exposure data.

I gotcha. So, I guess in semi-auto mode, if you set the EV and/or any one of the other 2 points of the exposure triangle, the third is calculated for you. You use EV -0.7 and the aperture of 5.6 as the "zero" point and the camera calculated the shutter speed using those values.

 

[skybanditpictures]

I'm interested in what exactly is going on when in PRO mode shooting video. The f stop is fixed at 2.8. I was in a situation where it was pretty bright out so I set the ISO to 100 and locked the shutter. I kept pressing -EV and the image did get incrementally darker but I didn't notice any of the settings change. So what was changing?? Then I started clicking +EV and the image got incrementally brighter but again I didn't notice any of the settings changing until I got to a certain point at which the ISO started adjusting up/more sensitive.

So...when I was adjusting EV down maybe the ISO was actually adjusting down but the display capped the readout at ISO 100? No idea but I'd love to know. And I need to experiment more with this as well.