Overexposed Image by 3 full stops on P4P?

[metron]

I used Phantom3 Professional extensively, as well as DSLR full frame cameras,
I just upgraded to P4P and what I see is that exposure is overexposed by 3 full stops when comparing to P3P, or even to Canon5D mk3,
so even having strongest ND16 filter available makes it unusable.

Can anyone comment on it with their experience?

To give out more details as an example,
on a moderate sunny morning with some mild clouds in the sky:

P4 Pro
iso100, 8000, f2.8
iso100, 500, f2.8 (with ND16, 4 full stops)
1/500 is unusable

P3 Professional
iso100, 1000, f2.8
iso100, 50-60, f2.8 ( with ND16 )
gives perfect 1/50 shutter speed for 24fps filming

also did more controllable test in the room with constant light and it confirms the same result of EV=+3

Some might say that it has a bigger sensor and that is the reason,
but my understanding is that ISO, F-Stop, shutter speed are three numbers defining exposure light,
regardless of sensor size

thanks!

 

[jason]

I used Phantom3 Professional extensively, as well as DSLR full frame cameras,
I just upgraded to P4P and what I see is that exposure is overexposed by 3 full stops when comparing to P3P, or even to Canon5D mk3,
so even having strongest ND16 filter available makes it unusable.

Can anyone comment on it with their experience?

To give out more details as an example,
on a moderate sunny morning with some mild clouds in the sky:

P4 Pro
iso100, 8000, f2.8
iso100, 500, f2.8 (with ND16, 4 full stops)
1/500 is unusable

P3 Professional
iso100, 1000, f2.8
iso100, 50-60, f2.8 ( with ND16 )
gives perfect 1/50 shutter speed for 24fps filming

also did more controllable test in the room with constant light and it confirms the same result of EV=+3

Some might say that it has a bigger sensor and that is the reason,
but my understanding is that ISO, F-Stop, shutter speed are three numbers defining exposure light,
regardless of sensor size

thanks!

A larger sensor generally provides higher resolution but with fixed f-stop you still have to rely ISO, shutter and filters to control the exposure no matter the size of the sensor.

 

[metron]

A larger sensor generally provides higher resolution but with fixed f-stop you still have to rely ISO, shutter and filters to control the exposure no matter the size of the sensor.

Exactly my point, thanks Jason,
I do not know where the issue lies and if I should just replace this hoping that new one will not have the problem,
or the problem somehow lies in firmware/software

I tried to toggle Color mode, and EV meter changes value by a lot depending on the mode, None, Cinelike, D-Log,
while the same toggling on P3P keeps the value unchanged

Also, in photo mode on P4P, in manual exposure mode, EV simply shows incorrect numbers,
like the image may be way overexposed already, yet EV=-2, and only becomes EV=0,
when the image is completely blown out

 

[jason]

Exactly my point, thanks Jason,
I do not know where the issue lies and if I should just replace this hoping that new one will not have the problem,
or the problem somehow lies in firmware/software

I tried to toggle Color mode, and EV meter changes value by a lot depending on the mode, None, Cinelike, D-Log,
while the same toggling on P3P keeps the value unchanged

Also, in photo mode on P4P, in manual exposure mode, EV simply shows incorrect numbers,
like the image may be way overexposed already, yet EV=-2, and only becomes EV=0,
when the image is completely blown out

Are those filters screw on and if so do they threads on the face side to add another filter? Of course the only problem with staking filters on a fixed lens is that you will see the frame of filter in the video/photo as though the video/photo had a vignette

 

[metron]

Are those filters screw on and if so do they threads on the face side to add another filter? Of course the only problem with staking filters on a fixed lens is that you will see the frame of filter in the video/photo as though the video/photo had a vignette

I only use DJI filters, they are non-stackable,
it is clearly the issue in EV-metering system,
I wish I had another P4P side by side to compare.

For instance, I do not even understand why in Auto Mode it would meter Exposure with EV=0,
but if I switch to manual mode, and use exact same settings, it would be showing me EV=-2,
untill I keep overexposing image by 3 full stops,

I will be sending it back to BHPhoto, and asking for a new one, if do not find answer over the weekend ;(

 

[jason]

I only use DJI filters, they are non-stackable,
it is clearly the issue in EV-metering system,
I wish I had another P4P side by side to compare.

For instance, I do not even understand why in Auto Mode it would meter Exposure with EV=0,
but if I switch to manual mode, and use exact same settings, it would be showing me EV=-2,
untill I keep overexposing image by 3 full stops,

I will be sending it back to BHPhoto, and asking for a new one, if do not find answer over the weekend ;(

Get an RMA from B&H and send it back. I've dealt with B&H for years and their return policy is really good.

 

[Meta4]

Exactly my point, thanks Jason,
I do not know where the issue lies and if I should just replace this hoping that new one will not have the problem,
or the problem somehow lies in firmware/software

Also, in photo mode on P4P, in manual exposure mode, EV simply shows incorrect numbers,
like the image may be way overexposed already, yet EV=-2, and only becomes EV=0,
when the image is completely blown out

This shouldn't be happening and has nothing to do with sensor size.
Have a look at your white balance number as well to see if that's going crazy.
Although if it was you'd probably be complaining about a yellow cast rather than over exposure.

 

[F3honda4me]

Have you tried auto settings to see if that's blown out too? If it's a bright day out it takes a rather high shutter speed not to have everything look overexposed.

 

[AIRSPACE]

A lot of more experienced Phantom users will say the histogram is not accurate, phantom always overexposes and the only thing you can really trust is the zebras. I tend to rely on those heavily now

 

[metron]

Have you tried auto settings to see if that's blown out too? If it's a bright day out it takes a rather high shutter speed not to have everything look overexposed.

In automode, it behaves more reasonable, the difference is only one full stop, but once I switch to Manual, and use the same settings chosen by Auto, the image is blow out completely, and the difference in value even depends if it is Video mode or Photo mode, like in Photo mode EV=-2, even though image is clearly overexposed, in Video mode it would show EV=+2, yet it only becomes EV=0, when I dial 3 stops down.
It also varies on Color Profile, way too many variables to experiment with,
yet when I work with Phantom3 professional, it is consistent regardless of Color profile, photo or video mode, manual or auto,
I am just too tired to experiment with all the settings )

 

[Cornelito]

Same problem here with metering. EV shows 0 but footage is way too much over-exposed. I'm not using any filters though.

Sent from my SM-G935F using Tapatalk

 

[metron]

Same problem here with metering. EV shows 0 but footage is way too much over-exposed. I'm not using any filters though.

Sent from my SM-G935F using Tapatalk

Do you also see this problem in Manual mode / Photography mode?

For most of my testing I also did NOT use ND filter to have one less variable.

I use ND filters for video on any camera and I showed the second problem,
that if I keep f-stop at 2.8 then even with strongest ND filter I get 1/500 shutter speep which is bad, and without ND it is 1/8000
( the problem at its worst when I shoot in custom Color mode such as D-log)