Turning on the subtitle option on the Mavic Mini will write data every second which is encoded into the video as subtitles.

The data can be extracted into an SRT file and will look like this:

60
00:00:59,000 --> 00:01:00,000
F/2.8, SS 202.82, ISO 110, EV -0.7, GPS (-115.1745, 36.3032, 16), D 9.47m, H 41.50m, H.S n/a, V.S n/a

61
00:01:00,000 --> 00:01:01,000
F/2.8, SS 60.30, ISO 200, EV -0.3, GPS (-115.1745, 36.3032, 15), D 9.43m, H 41.60m, H.S n/a, V.S n/a


These two examples were picked because they are consecutive (seconds 60 and 61) but different.  I understand most of the data but have not figured out the SS field.
SS sure sounds like Shutter Speed but I have not been able to figure out the relationship of the numbers shown above ( SS 202.82 and SS 60.30) to shutter speeds expressed as fractions.  At first I guessed that they might be expresed in miliseconds but they did not convert to any common shutter speed fraction.

Does anyone here know what the SS field is and if it is in fact Shutter Speed how is it converted to a more meaningful fraction representation?

Thanks.

Wondering this as well!

Shutter Speed maybe?

Now I'm curious, too.  Did the exposure change two stops between seconds 60 and 61?

With this being an electronic "shutter", the shutter speeds don't necessarily need to be constrained to the usual shutter speed progression we're used to from "normal" cameras.  So odd values might be used.

These might be microseconds.  The first one, 1/4930th of a second, and the second one 1/16584th of a second.  I know some of these digital video cameras like in the security cameras go upwards of 1/100,000th of a second for the high end of the shutter speed.  Without being able to stop down a mechanical aperture, they have to be able to use very fast shutter speeds to deal with bright daylight scenes.

Sigmo Posted at 1-12 00:14
Now I'm curious, too.  Did the exposure change two stops between seconds 60 and 61?

With this being an electronic "shutter", the shutter speeds don't necessarily need to be constrained to the usual shutter speed progression we're used to from "normal" cameras.  So odd values might be used.

I changed the EV from -0.7 to -0.3 between 60 and 61 and ISO went from 110 to 200.

TDZHDTV Posted at 1-12 00:00
Shutter Speed maybe?

That is what I had initially thought.

Can't delete a post.

SS=Super Sayin

Roy Rogers © Posted at 2-21 15:59
SS=Super Sayin

Where I come from SS is Submarine Service.

BobWinNV Posted at 2-21 16:02
Where I come from SS is Submarine Service.

I wouldn't try Diving with the Mini until that's confirmed

Roy Rogers © Posted at 2-21 16:03
I wouldn't try Diving with the Mini until that's confirmed

More folks should take your advice.

My guess: 1/202.82 th of a second; 1/60.3 th of a second...etc. However, not sure what it would display for a 2, 4, 8... second long exposure.

tdorego Posted at 2-27 12:54
My guess: 1/202.82 th of a second; 1/60.3 th of a second...etc. However, not sure what it would display for a 2, 4, 8... second long exposure.

Your most likely right.  Thanks for the input.

It would make sense as on older SLR's the "1/" portion of the fraction is eliminated to be able to fit on the small dials they used. However, if you manually changed EV this should not effect the SS and ISO. You would simply have a brighter result on your screen. According to the data, you gained one f-stop on the SS and one f-stop on the ISO. Did you suddenly fly into a shadow?

tdorego Posted at 2-27 14:22
It would make sense as on older SLR's the "1/" portion of the fraction is eliminated to be able to fit on the small dials they used. However, if you manually changed EV this should not effect the SS and ISO. You would simply have a brighter result on your screen. According to the data, you gained one f-stop on the SS and one f-stop on the ISO. Did you suddenly fly into a shadow?

At this point I don't really remember accurately what I was doing.  I had just turned on the subtitles to see what information I would get.  I will have to run a controlled test to see what effects various camera settings have on the subtitles in relation to the various fields.

tdorego Posted at 2-27 14:22
It would make sense as on older SLR's the "1/" portion of the fraction is eliminated to be able to fit on the small dials they used. However, if you manually changed EV this should not effect the SS and ISO. You would simply have a brighter result on your screen. According to the data, you gained one f-stop on the SS and one f-stop on the ISO. Did you suddenly fly into a shadow?

I just got in from a MM flight.  I had the  auto exposure lock on and when I changed the EV value the auto exposure lock disengages allowing the Auto shutter and Auto ISO values to change.

BobWinNV Posted at 2-27 17:28
I just got in from a MM flight.  I had the  auto exposure lock on and when I changed the EV value the auto exposure lock disengages allowing the Auto shutter and Auto ISO values to change.

I have seen in one or two youtube videos, the exposure lock disengages when making a change to EV. I guess it would have to (contrary to my previous comment about the SS and ISO shouldn't change) to compensate for the change. In your example you went from -.7 to -.3 which is approx. 1/2 stop. Not sure why the result you got was about 2 full stops. I will also be checking/testing this myself.

tdorego Posted at 2-28 09:57
I have seen in one or two youtube videos, the exposure lock disengages when making a change to EV. I guess it would have to (contrary to my previous comment about the SS and ISO shouldn't change) to compensate for the change. In your example you went from -.7 to -.3 which is approx. 1/2 stop. Not sure why the result you got was about 2 full stops. I will also be checking/testing this myself.

Please let me know if you find anything interesting and I will do the same.

tdorego Posted at 2-27 14:22
However, if you manually changed EV this should not effect the SS and ISO. You would simply have a brighter result on your screen.

I don't think that's correct. You can't "simply have a brighter result" if you're not changing any parameters that affect brightness. And those parameters are the aperture (fixed, can't be changed), ISO and shutter speed. So when you're changing the final result (the EV), the software will decide how to balance ISO and SS to get that EV.

Sigmo Posted at 1-12 00:14
These might be microseconds.  The first one, 1/4930th of a second, and the second one 1/16584th of a second.

That seems way to high of a shutter speed, I don't think that's possible. The most likely possibility to me seems to be miliseconds. You can easily deduce if it's a duration (e.g. miliseconds) or just the 2nd part of a fraction by pointing the camera at something dark and then at something bright. If that number gets smaller when pointing it at the bright subject, then it's a duration, so most likely ms. If it gets bigger, it's the 2nd part of the 1/x fraction.

Dirty Bird Posted at 2-28 11:06
That is much preferable to the Schutzstaffel...

I totally agree with you on that.

It’s shutter speed

TDZHDTV Posted at 2-28 11:10
It’s shutter speed[view_image]

That is what I had figured but was having problems with the numbers.  Since it is a digital shutter I guess it can be numbers other then what we are used to seeing on cameras.

@tdorego  

Here are some screen snaps from the video test that I ran on 2-27-20.  Mini was wearing a Freewell ND8 filter for these tests.

BobWinNV Posted at 2-28 22:28
@tdorego  

Here are some screen snaps from the video test that I ran on 2-27-20.  Mini was wearing a Freewell ND8 filter for these tests.

Your last set of pictures at different settings tells you all you need to know!  
Think about the exposure triangle: Aperture / Shutter Speed / ISO.  So when adjusting the EV exposure you're asking the software to adjust either the shutter speed or the ISO (as the aperture is fixed).

Look at your last two pictures; you change the EV from -1.3 to -2.  The software decides to change the ISO to 210 (potentially making the picture brighter) but drops the shutter significantly to make the picture darker.  
If you have an ND 8 on, then a shutter speed of 1/30 second would be typical.  
So yes, SS = Shutter Speed, and yes, the displayed digital number is the denominator of the 1/
(ie 1/30  1/60  1/20 etc )

I'm just trying to work out what the decimals are actually representing. It seems unlikely these are part of the actual shutter speed (why set it to  .15 or .30 or .60 as the shutter speeds halves each time), although it may literally be just that part of the actual shutter speed denominator being given to two decimal places....

I talk a bit more about varying these two values on this video; link jumps straight in at the point I start talking about it
CHeers
Ian

Ian in London Posted at 2-29 01:16
Your last set of pictures at different settings tells you all you need to know!  
Think about the exposure triangle: Aperture / Shutter Speed / ISO.  So when adjusting the EV exposure you're asking the software to adjust either the shutter speed or the ISO (as the aperture is fixed).

Thanks Ian. Yes, the decimals on the Shutter Speed was what confused me to start with and still puzzles me. The pictures above were posted to show folks following this thread that the SS is shutter speed and it does change when EV is changed even if AE is locked since changing EV also unlocks AE.

Perhaps Shutter Speed?

And there I was thinking Subway Sandwich all along.

Darn!!

On a serious note......

Any way to change the units of the subtitles from Metric to Imperial?

Thanks.

StubbornSwiss Posted at 4-4 09:58
On a serious note......

Any way to change the units of the subtitles from Metric to Imperial?

Not that I know of.

kikounet Posted at 4-4 04:04
Perhaps Shutter Speed?

Yes, it is Shutter Speed.

BobWinNV Posted at 4-4 11:11
Not that I know of.

Thanks Bob!

Thats kind of too bad though. I'm an imperial guy, not metric!!

DJI....... you really should look into this.

Plus the Flight Data Center units on my Android device. I'm stuck on using metric units only there too, while I can select metric or imperial on my ios device.

C'mon DJI...... you cater to an international market, so get it right!

Subtitles had Date & Time in previous (Phantom) versions. Do you know why this is not the case on the Mavic Mini?

kikounet Posted at 4-6 00:39
Subtitles had Date & Time in previous (Phantom) versions. Do you know why this is not the case on the Mavic Mini?

Sorry but I have no idea why DJI did not include them in the Mini subtitles.

StubbornSwiss Posted at 4-4 11:20
Thanks Bob!

Thats kind of too bad though. I'm an imperial guy, not metric!!

You need an update
https://en.wikipedia.org/wiki/Metrication_in_the_United_States

Bekoal Posted at 4-6 10:48
You need an update
https://en.wikipedia.org/wiki/Metrication_in_the_United_States

Lol...... you're right.

I grew up metric, but now I'm Imperial.

Don't think it will ever change over here.

BobWinNV Posted at 2-28 22:28
@tdorego  

Here are some screen snaps from the video test that I ran on 2-27-20.  Mini was wearing a Freewell ND8 filter for these tests.

Hi Bob,

I have a mavic mini, I have already activated the subtitles function in the app.
But I can't find the .SRT files.
Which iPad app are you using to read the files?
And do you know how I can extract the caption?
I have an iPad and a Windows PC. I didn't find any of them

Thanks,
Paulo from Brazil.

PauloPride Posted at 5-4 19:51
Hi Bob,

I have a mavic mini, I have already activated the subtitles function in the app.

I can see the subtitles VLC player once I turn on the view subtitle option.  DJI doesn’t create a separate .srt file for subtitles with the FLY app.  Well at least not with the Mavic Mini.  We will see what happens with the Mavic Air 2 soon.
Bob

This link will extract the subtitles into an .SRT file for you.
https://djitelemetryoverlay.com/subtitle-extractor/#

reply deleted

PauloPride Posted at 5-4 19:51
Hi Bob,

I have a mavic mini, I have already activated the subtitles function in the app.

This link will extract the TLM subtitles from your Mavic Mini video and build an .SRT file for you.

https://djitelemetryoverlay.com/subtitle-extractor/#