The sunset that never was

Color correction and grading are often used to promote a style, ambiance or ‘look’ rather than reflect reality. You want to meet the viewer’s ideal expectations, not boring reality.

After writing my last blog post, I realised there was no video that showing my tips on AVCHD editing being used in anger. This quick post puts that right. You can see the associated video here or by viewing the video below (I recommend you watch it full screen at 1920×1080).

Note that the youtube version is compressed from the original 28Mbit/s to 8Mbit/s, as are most web videos).

Note also that I don’t use a Sony Alpha A77 for the footage in this post: I use a Panasonic Lumix LX7  because I was traveling light, and the LX7 is my ‘DSLR replacement’ camera of choice. Both cameras use the same video codec and bitrates, so there is not much difference when we come to post production, except that the Sony Alphas have better depth of field and are therefore more ‘film like’, whereas the LX7 will produce sharper video that is less ‘filmic’.

Changing the time of day with post production

Myself and my partner were recently walking on Bingley moor (which is in Yorkshire, England, close to Howarth and Halifax, places associated with Emily Bronte and Wuthering Heights).

The final footage. Color grading and correction via Tiffen Dfx running within Adobe Premiere.
The final footage. Color grading and correction via Tiffen Dfx running within Adobe Premiere. Click on the image to open the original frame (1920×1080).

It was about an hour before sunset, and I thought it would be nice to capture the setting sun in video.

The original raw footage. Captured with a Panasonic Lumix LX7 with attached Polaroid variable ND filter.
The original raw footage. Captured with a Panasonic Lumix LX7 with attached Polaroid variable ND filter.

Alas, we were too early, and the recordings looked nothing like what I wanted.

A couple of weeks later we were walking in the same place in the early morning. I took some footage of the nearby glen (glen – UK English: a deep narrow valley). So now I had some footage of the moor and glen in evening and morning sun, but no sunset footage. Not to worry: I could just add the sunset via post production.

If nothing else, it would make a good example of how AVCHD footage can be edited whilst making large tone/color corrections without coming up against issues once you follow the handy tips from the last post!

The original footage

As per the tips in the previous post, I did the following whilst shooting the original footage

  • Shot the footage using a fixed shutter and aperture, and varied exposure using a variable Neutral Density Filter. Reason: as a general rule, shoot all footage at a fixed aperture  (typically around f3.5, going wider if you want low depth of field, or narrower if your subject is in the distance), and fixed shutter (typically twice the frame rate of your footage). Control your exposure via a variable ND filter.
  • Set the camera to record desaturated, low contrast and un-sharpened footage. Reason: this gives your footage more latitude for change in post-production.
  • Exposed the footage slightly brighter than I needed, being mindful of burning highlights. Reason: AVCHD tends to break up or produce artifacts if you increase exposure, but never if you decrease exposure.

Workflow

Color post production has two workflow areas

  • Color correction or correction of faults in the footage. A bucket could be too red, or a sky needs to be be more blue. Correction is done on a per clip basis, correcting color/tone issues or adding emphasis/de-emphasis to areas within the scene. Framing and stabilization is also performed on a per clip basis. As an aside, this is the reason why the left side of the footage seems to wobble more in the video: the right side has been stabilized with the inbuilt Adobe Premiere stabilization plugin.
  • Grading or setting the look of the final film. Grading is done equally too all clips and sets the final style.

Color correction

Here’s a quick run through of the corrections:

Color correction
Color correction
  • Top image. As-shot.
  • Second Image. Added an emulated Tiffen Glimmerglass filter. This diffuses the sharp water highlights and softens the video a little (I would not have had to do this if I was shooting with my Sony Alpha A77, and you would not have to soften the video if you were using any other traditional Canon/Nikon DSLR as all of them produce soft video). I also added a Fast Color Corrector to fix a few color issues specific to the clip (white and black point,  cast removal).
  • Third image. Added a warm red gradient to the foliage top left to bottom right. The shape and coverage of the gradient is shown in the inset (white is gradient, black is transparent).
  • Fourth image. Added a second gradient, this time a yellow one going from bottom to top. Again, the shape and coverage of the gradient is shown in the inset.

Color Grading

For this footage, I used an emulated film stock via Tiffen Dfx. The stock is Agfa Optima. I also added back a little bit of global saturation and sharpness using the default Adobe Premiere tools (Fast color corrector and unsharp mask).

The top image is the original footage. The middle image is the same frame after grading and global tweaks have been applied. For reference,  the bottom shows the frame after all color correction
Color Grading
  •  Top Image. Corrected footage so far minus the two gradients
  • Middle image. Grading and global tweaks (Agfa Optima stock emulation plus global color tweaks and sharpness).
  • Bottom Image. Adding the two gradients back for the final output.

Merging color correction and grading

Combining the two color change tasks (grading and color correction) is a bit of a black art, and I do both together. Generally, I start by picking an existing film stock from Tiffen Dfx or Magic Bullets Looks as an Adjustment layer. Then, I start adding the clips, color correcting each in turn, and switching in/out the grading adjustment layer as I go. Finally, I add a new adjustment layer for sharpness and final global tweaks. I avoid adding noise reduction as it massively increases render time. Instead, I add a grain that hides noise as part of the grading.

Reality vs. Message

Color correction and grading are often used to promote a style, ambiance or ‘look’ rather than reflect reality. You want to meet the viewer’s ideal expectations, not boring reality.

Color corrected/graded scene
Color corrected/graded scene

The video includes this frame. The leaves in the water are red to signify the time of year (autumn/fall).

Original scene (note also that the original scene is lighter than the final scene, as per my AVCHD shooting tips)
Original scene (note also that the original scene is lighter than the final scene, as per my AVCHD shooting tips)

Real leaves in water lose their color quickly, becoming much more muddy in appearance. I enhanced the muddy leaves towards earth-reds because ‘muddy’ did not fit with my message, even though rotting grey leaves are closer to reality.

Timeline

Here’s the timeline for the project.

Project timeline
Project timeline (click on image to view full size version)

I have my color adjustment and grading in as separate adjustment layers. (V2/V3)  The first half of the timeline is more or less identical to the second half except that the second half has the unedited versions of the clips on layer v4. These clips have a Crop effect (Video Effects > Tranform > Crop) on them with the Right value set to 50%. This is how I get the edited/unedited footage split-screens at the end of the video.

When adding backing sound, the music file is never as long as the video clip, so to make the two the same length, I often do this simple trick to edit the music so it is shorter:

  • Put the music clip on the timeline so that the start of the music lines up with the start of the footage, and
  • On a different sound layer, put another version of the same music on a the layer below such that this time the end of the music lines up with the end of the video.
  • Make the two soudclips overlap in the middle, and where they overlap, zoom into the waveforms and find and match the percussive sounds (generally the drums).
  • Fade between the two sounds on the overlap.
Matching sound sections
Matching the sound sections

In the timeline section above, I have matched (lined-up) the drum sounds on the layer a1 and a2 music clips (both of which are different sections of the same music file), then faded from layerA1 to A2 by tweening volume level. This will produce a smooth splice between the two music sections. If space allows, you should also of course match on the end of the bar (or ‘on the beat repeat’).  For my timeline, you can see (via the previous ‘Project timeline’ screenshot) that I have spliced between four sections of the same file.

Tools

During color correction I kept an eye on the YC waveform scope, which is available in Premiere and most video editing applications.

Footage vs YC waveform
Footage vs YC waveform

The YC wafeform shows both Luma (Y or brightness) and Chroma (C or color). Luma is Cyan, and Chroma is dark blue on the scope.

The x axis of the scope is the x-axis of the footage, so points on the y-axis are the YC values along the width of the footage itself. Sounds a bit complicated, but if you use the waveform on your own footage it becomes immediately obvious what the waveform represents.

For the broadcast standard I am using (European, PAL), true black is 0.3V on the scale, and true white is 1.0V (NTSC is very similar). The original footage is shown on the left side of the image, and the corresponding YC wafeform is shown below it. The waveform shows highlights in the sky area are clipping (we see pixels above 1.0V),  and the darkest areas are not true black (the wafeform doesn’t get down to 0.3V). The right side of the image shows the final footage and we can see that we now have no clipping (in either brightness or color saturation), and our blacks are closer to true black.

Keeping an eye on the YC waveform is always something I do when editing color. You may think your eye is good enough, but your vision gets tired or so used to color that it no longer recognizes casts, but the scope never tires and lies! Another useful scope to use for skintones is the Vectorscope. Something for another post…

Conclusion

This post shows the workflow I used to correct a small number of clips such that they could be added together into a single scene. The final movie shows a typical English autumn sunset (or at least, one where you can see the sun!) yet none of the clips were actually taken at this time of day nor under the lighting conditions of the final scene.

By manipulating the color of our footage via color correction and grading, we achieved our desired output despite the constraints of reality on the day!

Finally, by following additional steps and rules of thumb whilst shooting and editing the AVCHD footage, we have prevented coming up against its limitations. In fact, the only time in the video where you may see any artifacts is  the only place where I did not follow my own advice: at about 0.30″ I the footage has exposure increased slightly, and shows small artifacts in the shadows.

You can see all previous video related posts from this blog here.

Notes

  1. The music in the video is Spc-Eco, Telling You. Spotify Link.
  2. The YC graph is so much more useful than the histogram seen on most stills cameras that I often wonder why digital cameras don’t have the YC waveform instead! For example, the YC waveform not only tells you whether your image has clipped pixels, but unlike the Histogram, the YC tells you where along the width of the image those pixels are! You can still ‘shoot to the right’ using the YC (and it actually makes more sense) since brightness is Luma height. The YC also separates out brightness and color information, so you can see at a glance the tonality and color information within your photograph in a single visual. How’s that for useful!
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3 thoughts on “The sunset that never was”

  1. Hi SkyG.

    Thanks!

    If you haven’t already, take a look at https://howgreenisyourgarden.wordpress.com/2014/02/03/sony-alpha-dynamic-range-optimization-and-video/

    Although that post talks anout Sony Dynamic range optimization (DRO), the exact same feature is in the LX7, and its called iDynamic there,

    iDynamic on the Panasonic LX7 produces nicer (less macro blocked) shadows than the clip here, and adding a low contrast filter gives you a much more ‘analog film’ look (it rolls off the highlights, plus gives you low contrast, thus giving you more leeway in post).

    At the end of the post is an LX7 video that shows what iDynamic and a low contrast filter together do for LX7 output..

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