How to get the GH4 to look like the ARRI ALEXA?

[Felipe]

Hey guys. I'm a poor man with a small camera (GH4) but big dreams and high standards. So I'm really aiming for the Alexa look here, not really the film look. Is there any process I can use to make my GH4 look like an Arri Alexa? I know they are worlds apart and all, but what I really want is Alexa's colors. The dynamic range I can work around (lighting properly), but I need those cinematic colors. Is there a LUT that converts GH4 footage into Alexa's color scheme? It should be easy, right? I don't see why not. It's just colors. If one knows how the GH4 sees a scene and how the Alexa sees the same scene, it's just one step to deduct how to translate one footage into the other, with a LUT or something. Am I wrong? Can anyone help me with this?

[funkyou86]

29 minutes ago, Felipe said:

Hey guys. I'm a poor man with a small camera (GH4) but big dreams and high standards. So I'm really aiming for the Alexa look here, not really the film look. Is there any process I can use to make my GH4 look like an Arri Alexa? I know they are worlds apart and all, but what I really want is Alexa's colors. The dynamic range I can work around (lighting properly), but I need those cinematic colors. Is there a LUT that converts GH4 footage into Alexa's color scheme? It should be easy, right? I don't see why not. It's just colors. If one knows how the GH4 sees a scene and how the Alexa sees the same scene, it's just one step to deduct how to translate one footage into the other, with a LUT or something. Am I wrong? Can anyone help me with this?

How can I get my Škoda to ride like a Ferrari? The answer is: you can't.

Light your scene properly. Shoot in standard picture profile (unless you use external 10 bit recorder). Learn how to tweak colors in premiere/resolve. Use anamorphics to enhance cinematic look. Still won't look like an ALEXA footage, but you'll be satisfied with it

[hyalinejim]

That's quite a provocative question, but I like the way you think! Theoretically, it should be possible to get the GH4 to more closely match the Alexa. This is what I would do.

1. Shoot in 10bit V-Log to an external recorder

2. Use LutCalc to generate a VLog to Alexa LUT, to get the Panasonic gamma and gamut into the Alexa range

3. Shoot a colour chart with a GH4 and Alexa (this is the hard part) with the same exposure. Then bring both into Resolve. Apply the VLog to Alexa LUT to the GH4 shot and adjust the hue and saturation curves so that each square on the aligns with those in the Alexa shot, as seen on the vectorscope.

Using this kind of method I've got my XC10 to match my 5D3 MLRAW almost perfectly, both shooting a colour calibrated version of C-Log. That's not entirely dissimilar from what you're talking about. OK, they're both Canons but actually the colours coming from each of them were actually quite different.

Maybe you can find a shot of a chart shot on an Alexa somewhere and exactly replicate the exposure and lighting on your GH4. Good luck and don't forget to post your results when you succeed!

[scotchtape]

Check out some of the 3d out creator videos it looks pretty sweet - has camera matching tool.  Only problem is how will you get your hands on an Alexa...

[SlanderShot]

Totally agree with hyalinejim answer.

However It should be more easy to get closer the Arri Alexa look with the GH5.

[Felipe]

I'd really like to thank hyalinejim for the awesome insight and scotchtape for the tip. I'll be digging into that lut creation process and see what comes from it. If anyone has something to add, I'd appreciate. Thanks.

[hyalinejim]

This should get you started. It's only 720p, and is compressed for vimeo, and white balance seems off, but....

 

This might be a better resource, Log-C to Rec709 JPEGs:

http://www.drewmoe.com/digitalnoise.shtml

Quote

Tests were done using an Alexa XR, recording ARRIRAW at 2.8k resolution in LogC. Exposure and color was normalized across all shots. A LogC to Rec709 LUT was applied, from which 16-bit DPX files were created. All calculations were taken from these DPX files. Presented here are JPEG images, exported at full quality and 1920x1080 resolution.

 

[fuzzynormal]

Light properly.

[mercer]

Isn't the BMCC referred to as a Mini Alexa? They are so cheap on the used market right now, it may be worth looking into one of those instead of trying to get the GH4 to look like an Alexa.

[rndmtsk]

Use Open Color IO for After Effects to convert a log profile to another log profile

[BenEricson]

5D MKIII Raw.

[cantsin]

Look at this example - according to its maker, it has been shot with a GH4 using the internal codec, Panasonic 12-35mm F2.8, 20mm F1.7 & 42.5mm F1.7 lenses, Tiffen Black Satin filter, three cheap Yongnuo LED lights and a Nebula 4000 gimbal:

 

[Rudolf]

there are some impressive shots in that clip! I should dust of my GH4 an learn to use it properly

[BasiliskFilm]

Shooting in natural light on a sunny day, moving from light to shadow? That's when you really appreciate Alexa footage. Good luck with cheaper options.

[fuzzynormal]

1 hour ago, BasiliskFilm said:

moving from light to shadow?

Yup.  And then controlling the light in those kinds of scenes can make a "cheap" camera look good.

But anyone thinking they can slap on some post production magic to make sloppy footage look on par with elite gear is really misunderstanding how this stuff works.

We can make footage from cheap hybrid cameras look awesome for a lot of reasons, but 15+ stops of dynamic range is what it is.  A camera that squeaks out 12 just ain't the same.

So, rely on the fundamentals of the craft and make any gear you use look as best as it can.

[hyalinejim]

Here is an XC10 and 5D3 Magic Lantern RAW matched:

 

This was the starting point for each:

I achieved this by carefully matching the tonality of each camera. The colours were matched in Resolve using white balanced and tonally matched shots of an XRite Colorchecker. Then I applied the same look to each clip and tweaked levels slightly.