GH5 GH5 to Alexa Conversion

I would assume SAGE's LUT requires a correct exposure for the LUT's rolloff to operate correctly. Under or overexposed video would seem to require an adjustment first.
See how details get lost in a before and after comparison (due to a too the high exposure)

exp-adj.jpg

Ryan, could you share a unaltered dpx or a 10 bit tiff of that frame?
 
Last edited:
Cary Knoop said:
Well, there is highlight compression and highlight compression.

I think if you carefully make a shoulder to roll off the highlights then that can look great, however, compressing all the highlights into some high mid-tone mud is obviously not, at least not in my view.
Click to expand...

Sure thing. I hope you'll give me the benefit of the doubt on this one; I did take a great deal of care to set the shoulder for the intense highlight range
Many do prefer a higher ceiling, and Linear is a better starting point in that case
 
ryancglover said:
This is a shot that obviously is pushing the GH5s to the extreme. Sunny, blown out window, only a touch of bounce for fill, hazy, low-con look from the Classic Soft +1 filter and a big blue flare from the vintage lens right on her face.

The highlights are sitting at 768, where the LUT put them.


Vlog from camera:
View attachment 133184

V2 Soft:
View attachment 133185

Final:
View attachment 133186
Click to expand...

Hey Ryan, how did you handle/do the light switch moment, when it goes from warm to cool? That was pretty neat. Did you swap conversions at that point?
 
Sage said:
Sure thing. I hope you'll give me the benefit of the doubt on this one; I did take a great deal of care to set the shoulder for the intense highlight range
Click to expand...
No doubt, the shot was obviously overexposed (I understand why, although I would have over exposed a little less) so the LUT can't be blamed. No-one can expect a LUT to work as designed if the exposure is not correct.

A LUT that does a highlight roll-off must expect a proper exposure, so in this case, if an exposure adjustment node before the LUT is applied was added that issue should go away.
 
Last edited:
Sure, here's a DPX: https://we.tl/t-kwDN5lFc2P - Was shot internally at 150Mpbs 4:3 and transcoded to ProRes422 (DPX is 1080p)

Also, here's what the shot looks like developed with FilmConvert (and slight exposure drop) instead for reference:
FC colour_1.160.1.jpg

Sage said:
Hey Ryan, how did you handle/do the light switch moment, when it goes from warm to cool? That was pretty neat. Did you swap conversions at that point?
Click to expand...
It was a practical lighting gag, switched from a sodium gelled overheard fluorescent fixture to one with blue gel on the song cue. I think i did switch from the tungsten to the daylight LUT as well (razor-bladed the clip in the edit).
 
Thanks!

Yes, that shot is very challenging. The highlights are completely blown out.

You could get some more color out of it:

exp-soft_1.1.3.jpg

Or a bit colder and more contrasty:

exp-colder_1.1.4.jpg
 
Last edited:
The plan was always to blow out the window, since what was happening outside was decidedly not in keeping with the near-future setting of the video's story. So I overexposed all the shots with the window in the BG. Normally, I would've let her go a bit darker to save a bit more of the highlights.

I really like the way the GH5a LUT rolls off even in a messy shot like this. A bit of detail is lost but the transitions between different brightnesses near clipping look much smoother/pleasing to me.
The low-con desat-ed graded is obviously a taste thing, but I think how it ended up suits the rest of the video well enough.
 
I plan to buy this to screw around with on my GH4 footage, but I cant find info about required camera settings. Also, is the LUT in CUBE format or which? Not sure I can use in VEGAS.
 
Hi sage,

What do you expect the turn time to be for the BMD conversion?

And 5S, EVA1 conversions?

Now that the solid foundation is in place.
 
Cary Knoop said:
I think that is a bad idea, all it will do is destroy color information, color information that cannot magically be restored in post with an 8-bit compressed file.
Click to expand...

It's actually a great idea. Cine D clips the red channel quite easily, lowered saturation helps a lot and there's still more color than in V-Log L shots.
 
filmguy123 said:
What do you expect the turn time to be for the BMD conversion?

And 5S, EVA1 conversions?
Click to expand...

Awhile, definitely next year. I might very well work on the S before the P4K, as BMD is trying its best to not sell cameras ;)
I am working on the groundwork for those directly. I picked up a second Alexa yesterday, as the first succumbed to water damage (didn't realize I could call Arri for the records in advance). And trying to brush up on web skills.
Also, I'm still working on the GH5. I wrote a program last night to do averaging math right, because the tool I used for this end apparently was a bit inaccurate. Also, a neat bit of research soon

DeeZiD said:
It's actually a great idea. Cine D clips the red channel quite easily, lowered saturation helps a lot and there's still more color than in V-Log L shots.
Click to expand...

Yes, originally, I did the Cine-D conversion at -3, but the gamut was partly collapsed. I recently discovered far red bending at -5 that went under the radar because it was just beyond what I could measure, and added a manual corrective for V3
 
Alrighty, I'll grab a bag of popcorn, sleeping bag waiting on the patio doors for this thing to be birthed.
 
Any plans to do the S1? fWIW it seems to share the same EVA full vlog curve. I’m sure the specifics are different though

Dreaming of a GH5/S, EVA1, S1 package for all Panasonic that converts to both Alexa or BMD. Possible?
 
filmguy123 said:
Any plans to do the S1? fWIW it seems to share the same EVA full vlog curve. I’m sure the specifics are different though

Dreaming of a GH5/S, EVA1, S1 package for all Panasonic that converts to both Alexa or BMD. Possible?
Click to expand...

Its is; I hope to get to several cameras later this year. The pieces are coming together - as of this weekend, at an IP address on the internet, there is the first 'rough draft' of the new website. Its early yet, but I am working on a full web stack that will allow a custom encrypted update portal for example, that will make updates for more that one camera practical in the future (rather than individually emailing gigantic distributions). I am simultaneously wrapping a short film this month, and then it will be full steam ahead. There should be something by June-ish.
 
Hi all,

Anyone got a good workflow for using Alex’s amazing LUTs in FCPX, thinking mainly about the diffusion filtering - can’t seem to replicate that in FCPX

Rich
 
You must log in or register to reply here.
Back
Top