Saturday, March 08, 2014

Protune 2.0

There is new firmware out for your HERO3+ cameras.  I'm going to expand on some of the new HERO3+ Black Edition features related to Protune:

  • New advanced Protune™ controls for Color, ISO Limit, Sharpness and Exposure
  • Changes the Protune default settings for Color to "GoPro Color" and Sharpness to "High" 

Protune History

Protune was originally introduced in a firmware update to HERO2, and it was developed to solve the need of professionals already using GoPro cameras in feature film and TV projects.  Protune added a range of modes previously unavailable in any POV camera system: 24p, log encoding, H.264 long GOP at 35+Mb/s. See my first introduction of Protune at NAB 2012 -- this video was six months before its release.

Here is my October 2012 blog entry discussing the HERO2 Protune availability, just weeks before the HERO3 launch.

With the HERO3 Black Edition, Protune was included from day one. There were some small changes: 24p was now a standard video mode (no longer requiring Protune to be active), and white balance controls where now offered including CAMRAW.  Protune White balance controls for HERO3 and HERO3+ are:

  • AUTO - Same as in the standard modes
  • 3000K - Locked white balance for indoor warm lighting with an sRGB color space
  • 5500K - Locked white balance for sun conditions with an sRGB color space
  • 6500K - Locked white balance for daylight overcast conditions with an sRGB color space
  • CAMRAW - Lock white balance with sensor native color space.

CAMRAW is the only non-obvious addition, it doesn't attempt to saturate the image to the reduced color gamut, but standard, sRGB. Shooting in CAMRAW improves the ability to cut GoPro footage with larger cinema cameras, but it requires more post color correction -- except within GoPro Studio which handles the color matrix required automatically.

My shooting tip:  I always shoot Protune CAMRAW. The subtler color image is nice to start color correction upon, but CAMRAW is also lower noise. To saturate any image the difference in color channels is gained-up, blue channel noise is crossed into green and red channels, and vise-versa.  This happens in all cameras, and it happens in post saturation, but with CAMRAW it is under your control.

The New Protune

Protune within the new firmware on the HERO3+ Black Edition has changed again.  The original Protune was the "pro", "tune" that GoPro designed for all professionals, yet you don't have all the same needs. Now it is the mode for pros to tune their GoPro cameras.

Note: The new Protune defaults are very different to previous releases.

Protune is accessed within the tools menu by select CAPTURE SETTINGS:

Use the Mode button to scroll to PROTUNE and press the shutter.

While previously there was just on and off, with the number of new modes we added a reset to restoring Protune to the default configuration.  The default configuration turns all of Protune off except for the high bit-rate.  Protune is still the way to get the least compression / highest image quality.  If you're new to color correction, but want the least compression (for high action, high detail video), then turning Protune on is all you need to do.  Protune does required quality SD media, see GoPro SD Card Recommendations.
The next menu item exposed (with Protune set to On) is the white balance mode.   I'm showing my favorite CAMRAW mode here.
The white balance menu is unchanged from the last firmware with the default set to AUTO.

The first new menu sets the encoding curve.  It is described in terms of the video's appearance.  I also use the FLAT Protune log curve.
However the default for this mode is GOPRO COLOR, which is the standard high contrast, high saturation for the classic GoPro look. This is different from earlier Protune implementations which only had the FLAT log curve encoding of the video image.  GoPro Color was added to Protune to help with broadcast / news applications that rarely do significant color correction, but still want the best compression quality possible.

The next menu item is not completely obvious, as isn't common in other camera systems. While I know many pro users want full manual exposure, the nature of a camera with no mechanical iris on a super wide F2.8 lens, makes that tricky. ISO Limit is a step in the direction for manual control. A GoPro's exposure is controlled through shutter speed and sensor gain. ISO limit will restrict the sensor gain to the value selected or lower.
For night scenes you don't typically want to gain up the shadows to 6400 ISO (that is the default.)  If you want dark to be dark, consider 1600 or 400 ISO limit.  I haven't decided my favorite yet, other than not using 6400.  This is an improvement over the older Protune which didn't limit the sensor gain.  For those accessorizing their cameras with variable ND filters, you can use the ISO Limit 400 as a manual exposure mode of sorts. Through the ND, slowly stop the light down until the camera output begins to darken, you are now running ISO 400 with 360 degree shutter (hint: shoot 48p, then in post drop every other frame for 24p at 180 degrees -- also you will also have 2X slow motion ready when you need.)
I wouldn't know that icon meant sharpness either, but it is hard to visually depict sharpness with a off/on level monochrome display. Previous Protune modes had camera sharpening completely off, and whereas the new default and standard modes have the sharpness set to HIGH.
While I'm a fan of the old Protune with everything designed for post corrections, including adding sharpness, but I'm liking the medium mode as nice balance.  It doesn't often need additional sharpening (GoPro Studio will not default to adding any,) and it doesn't have any too obvious sharpening artifacts.
The mode I really needed: EV compensation.  I shoot a lot of events under stage lighting with my GoPros, bright lights on faces, so often blows out.  This problem is solved through EV compensation.

The EV compensation ranges from -2EV to +2EV stops of compensation, defaulting at zero.  I like to use -0.5 as my default, ready for anything, but I have used -1.0EV or -1.5EV for stage events.
Here is Protune 2.0 using the default settings, a 1:1 pixel crop from a 1920x1080 image.  No color correction applied.  Image is nice, but we can do more.

Here is CAMRAW with sharpening at Medium and EV at -0.5.  The color of the petals no longer clipping, under magic hour sunlight (EV -0.5 and CAMRAW helped.) 
Here is the same image as above with the color matrix applied (automatically) in GoPro Studio, some white balancing, contrast, sharpness added, output through the Protune preview LUT. The final image is more true the original rose coloring (this wide gamut magenta flower.)

My Favorite Configuration for HERO3+BE

While I've listed some of my favorite settings above, here are defaults for all my HERO3+ Black Edition cameras (one is not enough):

  • Video 2.7Kp30 (24p for night events or creative projects) with a Medium FOV (this mode is the sharpest with highest resolution for video presentation, with very little lens curvature.)  For aerial video I use 1080p60 Medium FOV (low light off.)
  • Photo Burst 5/1 at 12MPixels
  • Timelapse -- I don't use time-lapse photo, I use 2.7Kp24 or 1440p24 video modes and compute my timelapses is post (a GoPro Studio feature.)  See Rethinking Time-lapse
  • Protune On
  • FLAT - Log curve
  • ISO Limit 400 or 1600 as needed.
  • Sharpness Medium
  • EV -0.5 (or downward as needed)
  • Sound/Beeps OFF
  • Auto shutdown after 120 seconds of inactivity.

Added March 9th, 2014

GoPro App (Android and iOS)

These new Protune controls are all available through the latest GoPro App (free.)  An added bonus: within the latest GoPro App (version 2.3) will update your HERO3+ camera for you -- no need to update through the web site.

Hint: for updating the camera software via the App.  Get the latest app, and connect to the camera as usual.  Now the App knows which model you have, and it will contact the server to request any camera software updates.  This can take up to 24 hours of connecting to your camera (behavior from iOS and Android differs slightly.)

The next time you connect to your GoPro, this "Install Update" will appear -- click and follow the clear instructions.

Hint 2: For those that just can't wait 24 hours, after connecting to your camera, switch back to internet connected WiFi (i.e. not the camera.)  Then open the GoPro App and go to the App Settings (top right gear icon.)  Toggle the Auto Download on and off -- that should start the camera software download from the server.  See what will be updated under Camera Models.


Al Caudullo said...

I see these great new features are only for the Hero 3+.
Any chance that we will see an upgrade for the Hero 3?
Hope to see you again at NAB. Can't wait to hear the new announcments!
Al -3DGuy

David said...

I don't know if these features can be back ported to HERO3.

See you at NAB.

konrad iturbe said...

I will attempt to port these features into a hero3 black FW. I will post here the final result.

Al Caudullo said...

Thanks, I'll see you there. I'll bring along my new SuperHero 3D Gimbal. 3D printed.

Anonymous said...

Studying the specs of the SOCs in the 3 black vs the 3+ there seems like very little reason the 3 Black couldn't support these features too. If these don't appear (and I suspect the 3 Black has long been abandoned support wise) then it's due to exactly the same mindset Apple has for "encouraging" upgrades -- simply withhold new features from older products.

David said...

Al, Gimbal for 3D, interesting.

Unknown said...

I hope GoPro can give us a definitive reason why the update is not made available to the Hero 3's. It must be a technical limitation of the Hero 3 otherwise its a really shame that we are forced to buy new cameras just to get this upgrade. I'd be happy for them to come up with paid upgrades for firmware, that would be ok, not expecting everything for free but $400 to upgrade is a bit much!

Anyway, I can't imagine they haven't foreseen these questions being asked by Hero 3 owners so they must have a reasonable answer ready?

Anonymous said...


"The new software update for the HERO3+ is great! Unfortunately this will not be available for the HERO3 Black Edition camera and I certainly apologize for the inconvenience."

Great :(

I think a simple AE shift don't need any extra CPU power, what Black doesnt have.

Miguel said...

Great overview. Thanks.

I'm a videographer using a gopro for aerial shots. What would I miss if I stay with the Hero 3 instead of going for the 3+?
Is it just the AE shift and the sharpness adjustments or is there anything relevant that justifies the switch?

Abe Kislevitz said...

Awesome post, thanks David!

David said...

Miguel, there are a number of excellent upgrades to the HERO3+ hardware: sharper lens, less chromatic aberration, longer run times, faster WiFi and the video mode additions of super view and 2.7K Medium FOV(super nice images.)

Anonymous said...

And the case is 33% lighter :)
BUT. I don't like the image with more contrast in plus. Less detail in dark areas of the picture. In ptotune mode these details will be visible again?

Anonymous said...

Is protune only for video modes?
I mean it would be good for photos too: AE shift, RAW or minimal compression, colors, etc.

David said...

Protune Flat provides the extended dynamic range, showing more details in the shadows -- this is true on HERO3 and HERO3+ Black Edition.

Protune was designed for video only (makes sense the market it was targeting), however I agree more photo controls would also be nice.

Unknown said...

This is so awesome but you know what we need now to compliment the new customisable pro tune? Profiles!

Iam gonna be switching back and forth from high ISO low frame rate, low ISO high frame rate, normal gp mode, low ev/ high ev ... Would be so nice to have about 5 to 10 programable profiles which you can quick select some how on the go.

Maybe you can feature req please, Dave? 8-)


Bruce Allen said...

I would like full manual exposure very much. EG to be able to set my shutter speed and my ISO. Preferably wirelessly.

Would you mind expanding on:
"While I know many pro users want full manual exposure, the nature of a camera with no mechanical iris on a super wide F2.8 lens, makes that tricky."

I understand that the iris is stuck at F2.8 but I don't really see why there can't be a mode where we can just tell the GoPro how to shoot. All we'd need to do would be to turn all automatic systems OFF. Why is this not an option?

Thanks a lot - always enjoy reading your blog!

David said...


Here is the issue, without iris, gain and shutter really needs ND for practical exposure lock. While exposure lock for a bright sunny day would work fine, in this environment the camera rarely needs it, but many pros also would like 180 degree shutter. Which brings us to ND, which is not something GoPro has released -- but I hope they do (I've asked.) ND is tricky for such a wide FOVs, and variable ND looks weird (sky polaralization for wide FOVs is bizarre -- I've tried that too.) So I think we need a good ND solution, before we can convince the feature guys to add full exposure lock.

Unknown said...

Do you pros only use gopro studio? Or do you also incorporate adobe AE/PP and perhaps davinci resolve?

Meni Meller said...

As the new features will not be ported to the Hero 3.
I now wonder if we will start seeing customized gopro firmwares, something like CHDK for canon cameras.

David said...

@Christopher Hayden - Professionals would generally prefer a timeline editor, however the input room allows for the recreation of trimmed intermediate CineForm files, which many professionals do use.

Jesper said...
This comment has been removed by the author.
Jesper said...

Hi David, great post!

One question, why do you shoot the aerial video in 1080 medium instead of 2.7 medium?


David said...

For aerial I often want slow motion. And if slow motion is not the goal, the fast read out time for 1080p60 can reduce any rolling shutter jello that the gimbal doesn't remove.

Bruce Allen said...

Thanks David for reading my comment.

I'm still confused though: I don't need NDs.

I just want the option to manually set my shutter speed and my ISO.

Surely this shouldn't be hard? I mean, all we're trying to do is turn the auto-exposure completely off.

There are plenty of use-cases for this that don't need NDs.



David said...

It is complicated with some details I can't explain beyond what is already written. Exposure lock is possible, but manually setting shutter (ISO is somewhat settable) will do you little good without some additional method for controlling the light coming in.

Bruce Allen said...

Thanks David. Sorry you can't elaborate further. I guess there is some kind of technical limitation of the electronics that means it is stuck in Auto mode then. EG some component somewhere in the chain is from one of those consumer camcorders or cellphones and is stuck in Auto and you can't turn it off.

Each year I ask the GoPro reps this at Cinegear in Los Angeles and they usually just shrug and say "yeah we get that question a lot and we'd like that too. GoPro doesn't tell us anything though..."

As long as you can pass along our desire for actual real manual mode in the future, that would be awesome.

There are so many uses for GoPros that are hampered by this. For example: building a bullet time rig GoPros.
Q: What was the most challenging part of editing this?
A: Trying to match cameras both in exposure and color correction. The hero 2 cameras are auto everything so there was no way to really dial down your settings.

Again, the problem isn't primarily lack of ND. The key problem is a lack of ability to set shutter and ISO. Hopefully GoPro will select components that can do this in the future.

David said...

Your speculations are wrong. After all we do have array tech

David said...

My post went out before I was finished. There is ecosystem to deal with. Technically all cameras start as fully manual, auto exposure is simply the algorithmic setting of manual exposure. Exposure can be set to nearly any combination of ISO and shutter. However in full daylight very few combinations will make sense, why I mention ND. If you had manual, other than for array projects, you wouldn't find it all that useful, you would be running for ND immediately. ND on such a wide lens is very tricky. So my hope (I have too little influence over accessories) is we do produce ND filters (like the new dive filters), then maybe full manual exposure can exist.

Bruce Allen said...

Dear David

There are plenty of more uses beyond camera arrays. For example, aerial drones, lower light situations, indoors, etc.

There's a demand and we hope GoPro listens to it. I don't understand why GoPro insist on telling consumers what they want. It should be the other way around. I'm certainly not buying another GoPro until this gets fixed.

Please just add a "ReallyProTune" mode that allows us to wield the, terrible, potentially shot-ruining-power of (GASP) exposure change, potentially without NDs.

You may note that there are some people even going to the lengths of hacking your camera to circumvent this, EG:

"We have had plenty of shots ruined by auto exposure on the GoPro/Phantom, especially when tilting, so I started looking around for exposure lock ideas"

Anyway, I hope to hear some good news at Cinegear maybe when I (and other cinematographers) chat to your reps... hopefully more than "Yeah, I agree it's stupid. I don't know why GoPro don't add that."

Thanks for listening and replying as always.

Unknown said...

Seems like you can buy more GoPros now you have the hack you want. ;)

Michele said...

Hi David, is there a way to get the protune 2.0/Gopro color in post production? I find the protune preset in gopro studio usually oversaturated and bad while the new gopro color + protune on the hero+ gives the right compromise between protune's dynamic range and vivid color

David said...

The Protune preset is Studio is just metadata, it is non-destructive and only a starting point. It is only the application on an S-curve, not addition saturation. I typically reduce the contrast from the default before other enhancement. Remember Protune Flat is designed for color correction, so a default correction will not be good all situations.

TheDiveO said...

David, for Protune 1.0 there exists a known tonal curve for working with Protune footage in post in video editors not supported by GoPro. It basically is the reverse of the compression curve (you call it a log curve) used for all three primary color channels. I've documented my knowledge and findings on my blog for other open source users who need to work with Protune footage.

With the H3+ this obviously has changed. Applying the same tonal curves to H3+ Protune flat footage results in a severe color tint, kind of sepia-like. So it seems as if Protune 2 now uses different compression curves for the R, G, and B channels ... or did the whole compression model change even more?

The open source community, namely Kdenlive users, would be very grateful if we could get the data of the tonal curves for uncompressing H3+ Protune 2.0 footage.

David, can you help?

Thanks in advance!

David said...


Please try again with other sources as it has not changed. In GoPro Studio we do nothing different between H3 and H3+ for processing Protune Flat.

To map Protune Flat back to linear light (not display gamma, which you need also)
linear = (pow(113.0, input) - 1.0)/112.0; // all values normalized 0 to 1.0

Adding a display 2.2 gamma will not get you to GoPro Color, that is magic sauce that is not published, but should not be needing for the professional applications Protune Flat is intended.

TheDiveO said...

Thanks David for your quick response!

For the H3 with Protune I managed to create a good emulation of the GoPro color profile that does a decent job ... at least for my needs. I also published it on my blog and YT channels so others can build upon my findings.

Of course, as I'm doing post myself, I don't need GoPro's magic sauce and also don't emulate it ... except in terms of increasing overall color saturation.

Your reply with respect to the H3+ Protune tonal curves leaves me dazzled. I've got two reports from at least two different H3+ users that clearly indicate that H3+ Protune footage with WBRAW and FLAT differs significantly from H3 Protune WBRAW footage. The first report is several months old and the second just came in a few days ago. Both report sepia-like tint. The footage they send me clearly shows this, while the same scene shot without Protune doesn't exhibit this tint.

Anyway, many kudos for specifying the Protune tonal curve formula ... so far all I had were the parameters of the decompression bezier curve. This helps me to verify my information and to port it over to other video editors more easily. So thank you very much again!

TheDiveO said...


sorry for pestering again. I don't understand the formula you've given. While I'm not clear whether input is the luma value or either an R, G, or B value this curve basically darkens the image. At least if pow(a, b) means a^b (or a**b for us FORTRAN die-hards). I would have expected an S-shaped curve that allocates more detail to the ends, that is, to the dark and bright ends. If it is a log curve then there may be more detail in the shadows but never in the lights?

David said...


It is a pure log curve, applied in the R,G,B domain (sensor data, prior to white-balance and color matrix when using CAM_RAW.) See the original post for more on log curves

and even further back on Log vs Linear

TheDiveO said...


thank you very much for taking the time to (hopefully) set me on the right track. Stu's ProLost blog article you linked to was also of great help.

So I was basically phrasing my question wrong (more or less completely). Hoping that rephrasing this time yields the proper question: What I would like to know is how to translate from the 8bit Protune log encoding into the 8bit gamma 2.2 encoding. Why? Because that is the transfer function to start with when importing Protune Raw footage into any open source video editor. Thus way, other users are as well as I'm getting proper contrast at the cost of detail loss in the shadows. Adjusting the transfer function then would allow me to work out details.

(I've left out the color space topic, which I still need to learn more about. But I'm under the impression that Protune also uses the Rec 709 color space.)

David said...

You can do it this way:

input = (float)RGBinput / 255.0;
linear = (pow(113.0, input) - 1.0)/112.0;
gamma22 = pow(linear, 0.45);
RGBoutput = gamma22 * 255.0;

This will not give the contrast of a classic GoPro Hero look, but it is closer.

For more contrast do the following:
input = (float)RGBinput / 255.0;
contrast = 0.5 * sinf(3.14159 * input + 4.71239) + 0.5;
RGBoutput = contrast * 255.0;

TheDiveO said...


thank you very much for this additional information! Your sin contrast tonal curve in Rec 709/sRGB is what I was looking for since some time. Your explanation is proof that the tonal curve I found a long time ago in a Kdenlive forum is indeed "correct". In addition, your formula now allows me and others to reproduce this "Protune" tonal curve in any open source tool when necessary (if only as a starting point).

Bruce Allen said...

OK, now we have filters.

*Now* surely GoPro will let us manually set shutter speed and ISO, right?

Bruce Allen

David said...

No idea, but I got to get me some of those filters. ;)

DanH said...

Can I damage sensor if I use your video method for time lapse of rising sun?

David said...

"Can I damage sensor if I use your video method for time lapse of rising sun?" No. Video or stills, there is no iris or mechanical shutter, so the same about on light hits the sensor, even if the camera is off.

DanH said...

Thanks. What settings and workflow do you recommend for night to daytime sunrise video using video and Srudio Premium ( I might have posted this reply accidentally in another blog entry )

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DanH said...

I made test video of time lapse sunset using 1440 24p. Protune On, Flat, ISO Limit 1600, CAM_RAW. Can you recommend any tutorials/ resources for post using Studio Premium?

Cameras Like Gopro said...

Now it is the mode for pros to tune their GoPro cameras. ...

thejohnnyoshow said...

Regarding being able to control the shutter speed, I understand why its not completely doable, but having a limit to prevent the shutter speed being lower then a set value would be helpful possibly helpful in preventing rolling shutter right?
for example i would love to use 2.7 but hardly ever do because of rolling shutter, and its not like we can set the fps to a higher rate to prevent the shutter speed from going down to slow. for example if i film in 1440 48 it stabilizes pretty well in premier with warp. but forget it on 2.7 but if we could prevent the shutter speed from going below a certain amount that would be nice, if it was getting to dark and had already hit the stop it would go as far as it could based on the iso setting and then if its to dark to be it, but as it is now that not even an open for me.

of course no the go pro 4 has 50 fps on 2.7 so that's great but again on 4k we can only do 30 so a bigger problem with stabilizing because we can not prevent the shutter speed from going to below speeds like 1/48

Or am i completely misunderstanding why i can not stabilize 30fps video very well.

Anonymous said...

Great resource page. I have fine tuned my GoPro Hero 3+ Black settings to use Protune (CAM RAW) using 1080 60fps. My concern now is exporting the footage... Do I export it the same as the capture or 30 fps (HD 1080p or Custom). I have seen people film in 60fps, slow it down 50% then export at 30fps. This is for Youtube... any suggestions? Thanks

David said...

Both are viable workflows. Youtube also supports 60p now, so it all depends on the look you want.

balazer said...

Hi, David.

Can you please specify the primary chromaticities for CAMRAW? Is it the same for each of the different GoPro cameras? I am working on an ACES IDT for Protune.