Little Gems #3 – Curves ‘Snap-To Neutral’ Command

What’s one of the fun things when working in a brand new, completely updated version of the software you use professionally? Why, discovering all the little features that didn’t make it into the marketing material! That’s what this little series is about. As I discover nifty stuff about Resolve 12, I’ll point them out right here in this Little Gems series.


DaVinci Resolve 12: Snap a Curves point back to neutral

Have you ever placed a point on a Curve, only to add a second point to isolate the first point to a very specific part of your image? In DaVinci Resolve 11 and earlier we had a grid in the Curves area to help us bring our control points back to neutral. In DaVinci Resolve 12, there is no grid to help us find the neutral position. This brings us to…

Little Gems #3: ‘Snap to Neutral’ Curves command in DaVinci Resolve 12

I learned this Little Gem while chatting on the phone with Blackmagic’s Alexis Van Hurkman. I thought it was a bug—and Alexis clued me in otherwise… After placing a control point: As you click and drag a control point back to neutral, hold down the option key to reveal ‘neutral’:

Click-drap and press Option to snap a Curves point to Neutral

A new command in DaVinci Resolve 12: Click-drag+Option to reveal the ‘neutral line’ and snap your control point to it.

With a point selected, and while option-dragging, a line pops up showing you the neutral centerline. Keep dragging and the point will SNAP to neutral! Let go of the option key to make a slight move off the neutral line. No more second-guessing yourself.

One of my favorite Little Gems so far in DaVinci Resolve 12.

– pat

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Little Gems #2 – ‘Ignore THIS Track’

DaVinci Resolve 12: New timeline navigation option in the Color page

What’s one of the fun things when working in a brand new, completely updated version of the software you use professionally? Why, discovering all the little features that didn’t make it into the marketing material! That’s what this little series is about. As I discover nifty stuff about Resolve 12, I’ll point them out right here in this Little Gems series.


Imagine you’re working on a 300-shot timeline with a ‘letterbox mask’ on the top-most tracks

What do I mean by that? Notice in this next screenshot how I’ve got two long clips on Tracks V3 & V4… they’re the same full frame black .jpg, cropped to create a letterbox.

All tracks active in the Color Page of DaVinci Resolve 12

Notice how all four tracks are active. Also notice Shots 1 and 2 are the full-frame black overlays for letterboxing.

Also notice how the black JPEGs are also shots 1 & 2 in our thumbnail timeline. Why have we used these JPEGs instead of Resolve’s built-in letterboxing tools?

There are a few flashback sequences where the Letterbox is supposed to disappear and the image goes full screen

This makes masking with Resolve’s built-in toolset a little tricky and using top-level tracks just for letterboxing makes a ton of sense.  But there’s a problem and it was posted on Blackmagic’s DaVinci Resolve forum a few days after the launch of DaVinci Resolve 12 Public Beta 1.

Here’s the unexpected problem that the Original Poster found when navigating the timeline with top track letterboxing while color grading:

The trouble is, when I’m grading the clips on track V1, and I pause playback, the clip on V5 gets selected, so then the up and down arrow keys cause the playhead to jump far away from where I was working.

Elliott Balsley

If you’ve color graded more than a handful of jobs on DaVinci Resolve, you know precisely what Elliott is experiencing. Basically… every time he pauses playback, Resolve re-selects those top-level shots as the active shots. If he up- or down- arrows, he jumps to the first or last frame of those shots.

In a 30 minute sequence, that’s a major annoyance.

Before DaVinci Resolve 12, the only way to solve this navigation problem was to turn those top-level tracks off, hiding the letterboxing. And if you’ve ever graded a project that was shot full frame but protected for the letterbox, you know your color grading decisions change if that letterbox is turned off vs turned on.

It’s a maddening predicament…

You need the track turned on for color grading, but you can’t navigate shot-to-shot using the keyboard without turning the track off. This gets us to…

Little Gem #2: ‘Ignore Track for Transport’

DaVinci Resolve’s Product Manager, Peter Chamberlin, chimed in with a solution that’s brand new in DaVinci Resolve 12:

There is a new feature in v12. On the color page, hold option key and select the track number on the far [Left Hand Side] of the track that you wish to be ignored for transport selection. The track number is red when in this mode.

This will hide items on this track from the thumbnails but when the CTI is over those clips you will still see their impact on the viewer.

Ideal for mattes, grain, titles, etc.

Peter Chamberlin, DaVinci Resolve Forums

Two tracks are ignored for timeline navigation in DaVinci Resolve 12

Little Gem #2: After option-clicking on Tracks 3 & 4, they turn red. The tracks are active but ignored for timeline navigation purposes while in the Color Page.

In the screenshot above, tracks 3 & 4 are active, but ignored

Notice how they’ve disappeared from the thumbnail navigation, no longer labeled as Shots 1 & 2. Now you can have overlays spanning entire timelines, keep them active for color grading decision-making and never have them get in the way of navigating the timeline on the Color page.

THAT is the definition of a power users’ Little Gem 🙂

– pat

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DaVinci Resolve 12 – Little Gems #1

(plus, why this Gem is slightly cracked)

What’s one of the fun things when working in a brand new, completely updated version of the software you use professionally? Why, discovering all the little features that didn’t make it into the marketing material! That’s what this little series is about. As I discover nifty stuff about Resolve 12, I’ll point them out right here in this Little Gems series.


About Resolve 12’s new Curves editor

Before we dig into Gem #1, DaVinci Resolve 12 has given us a new ‘unified’ Curves interface which can use a little explanation.

Starting with Resolve 12, no longer do we need to jump into a larger ‘gigantor’ interface to make niggly tweaks to our custom curves. In addition, more closely mimicking the Avid Symphony curves editor, the end-points of our curves are now free floating. This has been a feature request of mine for quite a few years!

The Resolve 12 New Curves Editor

The curve editor in Resolve 12 has been completely redesigned.

 

Why? First, it make Resolve more approachable to Symphony colorists who can draw curves the way they’re used to (although to get to parity with Symphony’s curves, this new curves interface needs little Text boxes so we can numerically tweak our points more precisely than a mouse allows). But there’s another reason I wanted free-floating end points…

Free-floating end points allow more precise LAB corrections

I’ve got an example from a job I graded earlier this year, BloodyCuts.co.uk’s ‘Outer Darkness‘. For one scene, I used LAB to handle the Saturation expansion. The scenes had low light levels and I found LAB saturation expansion worked very cleanly and really popped the skin tones where I wanted them to pop. Here’ a screenshot with the LAB node active, graded in Resolve 11’s old Curves editor:

Resolve 11's Gigantor Curves Interface

Resolve 11’s Gigantor Curves Interface with the green and blue channels set for contrast expansion of AB in the LAB colorspace (click to open full size).

My problem here? Look at the roll-off at the 100IRE and 0IRE marks. See how the curves sharply roll-off? And then there are the additional points I need to add to the middle of the graph to straighten out the contrast expansion as much as I can. I need to write 3 points simply because Resolve 11 (and earlier) wouldn’t let us move the end points and create a perfectly linear contrast expansion.

(Also notice how the very center of the grid is being used to keep this contrast expansion as neutral as I can… we’ll be coming back to that)

I consider this a Faux-LAB grade. It works. I use it. But other apps  do this more cleanly and I prefer a perfectly linear contrast expansion since I’m a bit compulsive about these things.

In Resolve 12 I imported this project and pulled up the same shot

The import worked perfectly. It precisely replicated the grade I created in Resolve 11. Next is a screenshot from Resolve 12 with the Green channel rebuilt, pulling inward the two endpoints to give me a perfectly linear contrast expansion in the A channel. The type of curve I’ve wanted to write (but couldn’t) in the last few versions of DaVinci Resolve:

A linear green curve overlaying the 'old' blue curve

A linear Green channel (with the endpoints moved) overlaying the ‘old’ Blue Channel (with the endpoints pinned)

 

Take a close look on the overlay between the A and B channels (click to open the screenshot full size). The blue B channel meanders giving us more and less saturation as blue pixels move up and down the tonal range, compared to the A channel’s perfectly linear slope. THAT’s the advantage of being able to move our endpoints in the Curves graph, much greater precision in our curve writing.

But that’s not why I’m writing this post…

Gem #1: The New Curves ‘Copy To’ Command

While playing around with LAB, I pulled down the ‘ellipses’ option menu and found the ‘Copy to’ command.

The new 'Copy to' options in DaVinci Resolve 12

Click on the ‘ellipses’ pull-down menu to expose the new ‘Copy to’ commands.

 

When working in LAB, you’ll usually want to start with the A and B channels perfectly aligned to each other. Doing this by hand would be imprecise but thanks to the ‘Copy to’ Command, having made my change to the green A channel, I can perfectly copy that curve to the blue B channel.

Thank you, my Blackmagic overlords.

Except…

The Cracked Gem: No grid for referencing endpoint placement

If you scroll up to the Resolve 11 screenshot, you’ll notice a nice neat grid in the background of the Curves editor. I use this to more precisely ensure my LAB contrast expansions are perfectly symmetrical, with 50% always passing through the 50% mark. Take a look at this correction again, with the green A channel copied to the blue B channel, perfectly overlaid and answer these next questions:

Are the bottom endpoints pulled into the box precisely as far as the top endpoints are pulled in?

Is the center point of the AB channels perfectly crossing the center point of this graph, keeping the correction completely neutral?

The green and blue channels perfectly overlayed in Resolve 12

Using the ‘Copy to’ command, the blue channel perfectly matches the green channel (click to enlarge)

 

I have no idea. In Resolve 11 I’d just have to make sure the curve passes through the mid-point of the lined graph and I’d know my correction is ‘passing through neutral’.

In Resolve 12 I have to take a ruler and measure my screen. There’s a reason Photoshops Curves editor has a selectable grid size. Grids are USEFUL!

This is especially true when grading LAB. LAB benefits from the precise adjustments of the endpoints. The best we can do with this new interface is approximate. Which is all we could do in Resolve 11 but a completely different approximation.

So – while I appreciate the new Curves interface; while the new ‘Copy to’ command is indeed a Little Gem—we’ve gained one form of precision while losing another.

How do you make a HappySad emoticon?

– pat

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What Are The Origins of Post-Production’s ‘Gamma Wars’?

The Apple LaserWriter Print Dialog Box

Is THIS the start of the Gamma Wars? From the original QuickDraw Manual.

A few weeks ago I put a link into the Sunday Newsletter about a 2014 BBC White Paper on High Dynamic Range video. It’s a dense but fascinating read, partly because the Introduction does a nice job comparing modern camera sensors to the capabilities of the human eye. It also has an interesting discussion about the influence of CRTs native response on the choice of video’s ‘2.4 gamma curve’. In the summary of Section 2:

for many years the dynamic range of television displays was limited to about 100:1 by CRT technology. A non-linear “gamma” curve was used to equalise the effect of noise at different brightness levels in analogue TV systems. 

Elsewhere the White Paper discusses the non-linear “gamma” curve in CRTs:

Early television engineers took advantage of the non-linear characteristic of CRT displays to achieve [uniformity of noise], since the non-linearity of a CRT closely approximates a power law of 2.4

In other words CRTs were used because their native gamma response (nearly) perfectly matched their needs for natural-looking video images. Then, flat panel technology came along:

With the advent of digital TV the same gamma curve also allowed video to be quantised to 8 bits without significant contouring.

As the White Paper explains: At 8bits and above there’s sufficient narrowness between each step of brightness that the eye (usually) can’t see artifacts when using the same “gamma” curve as CRTs. Our Engineering Overlords declared the technology sufficient, 8-bit the minimum requirement for television delivery but they never thought to explicitly define the “gamma” curve—since we hadn’t yet entered the age of digital displays.

What happened on the computer side of video displays?

Why didn’t computer displays match video displays, especially since the early computer displays were CRTs?!? To answer, I put on my Google Gloves and this blog post from 2006 popped up, The Gamma Question: 1.8 or 2.2?

the standard CRT monitor built into the Mac wasn’t anything special either, still having a native gamma somewhere near the 2.5 mark. . . Apple specified how their QuickDraw graphics libraries recorded pixel values to pull the native gamma of the monitor down to 1.8. This made it so that a user adjusting an image on the Mac monitor created pixel values recorded by QuickDraw that printed as a reasonable match to the monitor image. This worked so successfully in fact that the 1.8 gamma became regarded as the gamma of the Mac monitor itself

And what were Apple computers matching their CRT display output to?

Freaking Black & White LASER PRINTERS.

Apple. Broke. the CRT. On purpose. To match QuickDraw to the printed page.

And thus began the Gamma Wars

Yes, I heard this story many years ago and still, forgive me if I can’t stop laughing. Apple has had an over-sized impact on our industry for MUCH longer and in ways than most of us realized.

Friggin’ QuickDraw. Crazy how this stuff happens, right?

– pat

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