How do I grade a Hypergamma?

[Paul Anderegg]

I have a PXW-X180, but I thought users of older Hypergamma capable cameras may have more advice on this topic.

I shoot night ENG, and my camera is around f9@2000, plus I deal with some pretty high contrast scenery. A typical high contrast scenario would be a pitch dark scene lit by my camera light, with very intense police spotlights on a car for instance. I play up my black gamma a bit to bring detail out of the ink, but standard knee has trouble coping with high contrast without looking a bit cartoonish as soon as I direct the camera at a human face.

I understand what a flat looking image looks like, and was pretty pleased with night interviews of subjects with very dim backgrounds using Hypergamma previously. Colorimetry got a bit weird on me in the flat. I am wondering how exactly are Hypergammas meant to be adjusted in post? I use FCP-X, and would appreciate any suggestions on the basics of making Hypergamma night news footage ready for 100IRE on air broadcast.

I normally need a quick turnaround on my footage to get it back to the station for broadcast. My XAVC footage takes forever to import and transcode. If there is any way to set a custom preset for the grade of my standard run of the mill footage in FCP-X, that would save a lot of time. I would think/hope that the way Hypergamma treats highlights as opposed to the knee would make across the board grading much easier. I know manipulating each clip would provide optimal quality, but I don't even have time to really get into that with standard gamma footage. Import, drop on timeline, APPLY CUSTOM GRADE to timeline, export.......that is my objective.

Any help on this subject would be greatly appreciated!

Paul

[Dave Sperling]

You may find that different camerapeople will use hypergammas in different ways.
Some think of it as a way to control highlights for later grading -- Others use it as a way to modify the look of what is being captured.
I personally find that different clients may either prefer or even request different 'looks' -- so I have a number of profiles saved (and named after) my clients. Thus I can easily return to the look a client likes when shooting for them.
As it happens, many of the clients seem to like a hypergamma (or the earlier cinegamma, which is a subset of the hypergammas). Certain clients do no (or minimal) color correction in post, so lighting and exposure are set for a finished image -- and in those cases the hypergammas are changing the overall gamma of the image, and particularly taking down the highlights.
As a reminder, take a look at this curve from Alister's website:

hypergamma curves jpeg | XDCAM-USER.COM

So obviously one of the biggest features is highlight control. One thing to remember when using the hypergammas, however, is that in every case you will see that you need more exposure to get your mid-tones to the same level than you do with a standard gamma! What this equates to is being potentially even more light-challenged when shooting in low-light situations!

In your situation I'd suggest staying away from a blanket post-process 'correction' since I think this will potentially create more problems than it will solve. Also remember that unless you're shooting s-log, you won't have the advantage of using a viewfinder LUT, so you're looking in the viewfinder at whatever gamma adjustments you've made to the signal.

In many situations I find that the hypergammas are great to control overexposed highlights. I'd recommend shooting a couple of tests under real world lighting conditions and seeing how it works for you.

[Paul Anderegg]

Thanks for the reply Dave. I am including a link below to some generic footage my X180 spits out. I found the #1 thing that makes a difference was calibrating the camera's multi-matrix with a DSC chart. With this type of footage and look, would you say that I am probably getting the most out of standard gamma, and Hypergammas might not give much of a visual advantage to my footage? The only clip in that link that shows off my highlight issues would be the 7-Eleven store in the background near the beginning. Most of these clips were put in there because they looked good, not because they were hard to cope with shots.

SONY PXW-X180 ENG NIGHT DEMO - YouTube

[Dave Sperling]

Choice whether or not to use hypergammas is very much a personal preference question.
I'd suggest that you shoot a quick test under your typical shooting conditions and switch back and forth between your standard gamma settings and Hypergamma 3. The contrast will probably feel a bit more aggressive in standard - while HG3 may feel a bit smoother and should control the highlights a bit better. I'm suggesting HG3 because you are shooting in the dark, and you don't take so much of an exposure loss with HG3 as compared to some of the others, plus it will help open up a little more detail in the darker areas.

[Dennis Hingsberg]

In a low light scenario you might want to use one of the hypergammas that has a higher middle grey value, for example the Sony F3 had a cine4 gamma curve with a very high middle grey value of 55-60%. This places the mid point much higher than normal which is a nice boost to the lower mid-tones and shadows. With this curve you wouldn't have to really do any grading and could shoot WYSIWYG.

Since the PXW-X180 only has the following hypergammas, none of them with highly placed middle grey points, I would suggest using HG4 because it is the highest dynamic range curve over HG1 and HG3, and it's middle grey value is set to 33. You could use HG3 which has a higher middle grey value but it's dynamic range is lower than 460. It's easier to just boost the mid-tones in grading but I would probably place preference on using the higher dynamic range curve.

HG1 3250G36 / HG2 4600G30 / HG3 3259G40 / HG4 4609G33

Another option is to overexpose one of the gamma curves by one stop and in post grading bring it down by one stop overall and you will have a much cleaner looking image. This of course eats a little into your highlight latitude.

For F3 users, here's a handy cinegamma reference booklet in PDF you can download which shows all the curves and where the middle grey point is for each curve.

www.starcentral.ca/forums/Sony%20PMW.pdf

For the PWX-X180 the placement of middle grey are the two numbers after the letter "G" in the name of each hypergamma:
HG1 3250G36 / HG2 4600G30 / HG3 3259G40 / HG4 4609G33

cheers,

[Dave Sperling]

Thanks Dennis!

Actually the OP question was about the PXW-X180 which comes with the newer HyperGamma settings, so the CineGamma numbers don't line up...

Have you run across an overlay of the Hypergamma curves against the CineGamma curves anywhere? The differences in the gamma presets always seem to make it a little tougher matching the newer cameras to my F3 (which still looks beautiful and continues to get its share of work...)

[Dennis Hingsberg]

thanks sir, I've updated my post.

cheers,