My latest book, “Fix It In Post” is available for pre-order now on Amazon.

Thanks to everyone who let me pick their brains over the course of the last few months.

The blurb:

“Finally!  A well-written software agnostic guide to fixing common problems in post ranging from shaky camera to film look!”

—Jerry Hofmann, Apple Certified Trainer; FCP Forum Leader, Creative Cow; Owner, JLH Productions

Fix It In Post provides an array of concise solutions to the wide variety of problems encountered in the post process. With an application-agnostic approach, it gives proven, step-by-step methods to solving the most frequent postproduction problems. Also included is access to a free companion website, featuring application-specific resolutions to the problems presented, with fixes for working in Apple’s Final Cut Studio suite, Avid’s Media Composer, Adobe Premiere Pro, as well as other applications.

Solutions are provided for common audio, video, digital, editorial, color, timing and compositing problems, such as, but not limited to:
* automated dialogue recording, adjusting sync, and creating surround sound
* turning SD into HD (and vice-versa) and restoration of damaged film and video
* removing duplicate frames, reducing noise, and anti-aliasing
* maintaining continuity, creating customized transitions, and troubleshooting timecodes
* removing vignettes, color casts, and lens flare
* speeding shots up, slowing shots down, and getting great-looking timelapse shots
* turning day into night, replacing skies and logos and changing camera motion

Fix It in Post: Solutions for Postproduction Problems

I haven’t seen much in the way of comparisons of the resizing filters available for Red footage, so yesterday I ran some quick tests. The “Redline” processor provides a choice of seven different filters for resizing clips: Bell, Mitchell, Lanczos3, Quadratic, Cubic-bspline, CatmulRom (sic), and Gauss. I took something fairly neutral we’d shot at 4k (4096×2048 to be exact) and down-rezzed it to something more feasible (2048×1024), to see how much sharpness was retained. I then decided that an exact 75% reduction in area is a bit too computer-friendly, so I also did a set down-rezzed to HD (letterboxed to 1920×1080).

There are a lot of available options for processing the clips, for the purposes of this test, I turned off sharpening and noise-reduction, set the detail to high, the ISO to 320, and applied a rec.709 gamma curve.

It’s possibly a little difficult to tell from this image, but the Lanczos and Catmull-Rom filters produced the sharpest results compared to the others. Although a difference matte between those two methods suggested there was a difference, I just couldn’t see it. I suspect that the difference in processing time between the two would also be neglible, even over a lot of frames, so I’ll probably just go with Lanczos when the time comes to actually prep the images for the online. What’s interesting is that the default filter used by the Red software is
Mitchell, which is probably the most middle-of-the-road in terms of sharpness.

As tests go, this one’s not bullet-proof, for example I didn’t test to see how the gamma curve affects the process, so I have no idea whether using a different gamma curve affect the interpolation (this would probably depend upon the order the Red software performs its processing, if it interpolates first and then adjusts the gamma, then there would be no difference between curves). The other problem is that this really only provides half the story– until we get this into a grading suite and see how it looks at speed it will be difficult to say for sure that one filter is perceptually better than another. I also can’t compare to how it would look to something similar shot in-camera at 2k, because we didn’t shoot anything 2k (although the general buzz around the Red forums is that shooting 2k produces far inferior results, at least with the current firmware).

The original 4k frame, along with the converted DPX versions, as well as layered Photoshop versions can be downloaded from here… if anyone wants a closer look (please note all images are Copyright 2008 Entitled Productions).

Crops… are all well and good, but sometimes you’d rather retain the complete, original image. For example, if you need to make a 4:3 dailies tape which contains 16:9 elements, you’d better be sure the whole image is there in case anything important is happening at the edges. In this case, what you need is a letterbox, rather than a crop.

A letterbox retains the original shape of the footage, typically filling the rest of the frame with black (in the case of Final Cut Pro and Motion, the underlying layers provide the rest of the frame, or if there are no underlying layers, the background colour is used). By default FCP will letterbox any footage that doesn’t fit the timeline completely, automatically scaling it so that either the top and bottom or the left and right edges fit completely within the frame. This means that ordinarily you don’t need to do anything to letterbox footage. If for some reason you do (and are happy to use FCP’s scaling process to do it), the easiest way is to adjust the scaling parameter until it looks right. If you need it pixel-accurate, you’ll have to get your calculator out and plug in some numbers to get the exact percentage:

( width of timeline output / width of footage ) x 100

Repeat this for the timeline output and footage heights and compare the two results. For a perfect letterbox, use the lower percentage. Conversely, for a perfect crop, use the larger percentage.

Starting with your original image–

 
–crop to fill the frame–

–or letterbox to keep the whole image.

Tip: To have FCP letterbox everything in a sequence use: Modify / Scale To Sequence

The only sure-fire way to check which shots Final Cut Pro has seen fit to resize automatically is to look at the motion tab for each shot. Make this easier for yourself by setting the canvas sync to Open, then quickly spool through the timeline with the Motion tab open.

The next part of this series will look at aspect ratios.

(Images featured in this article are Copyright 2007 BBC Worldwide Inc.)

In this part of the “Resizing Shots in Final Cut Studio series, we’ll look at different methods for cropping a shot.

Sometimes you need to adjust footage to fit into a different size frame. For instance, you may need to add high definition material to a standard definition timeline. In these situations Final Cut Pro will automatically scale the footage up or down to fit the timeline. However, any form of scaling (and particularly FCP’s default scaling) will reduce image quality. If you find yourself in this situation, calmly open the motion tab for the shot and set the scaling back to 100%. This will ensure you get a pixel-perfect rendition of the original shot, and FCP will instead crop the footage to fit, instead of scaling it.

What this means is that all the pixels that don’t fit within the frame are discarded, in the same way you use the crop tool on an image in iPhoto, or a pair of scissors on a disappointing article based around Final Cut Studio.

What becomes important at this point is the region of interest, that is, the part of the image you want to keep. Final Cut Pro will keep the image centred by default (performing what’s known in the trade as a centre cut-out), but that doesn’t mean you have to keep it this way. Instead you can use the Center control to reposition the image (we’ll be covering the “Pan & Scan” technique that dynamically repositions a shot over time in a future article).

There is another situation which may require the use of a crop, which is when you mix footage which is a different shape. The most common example of this is adding widescreen-formatted (16:9) material to a fullscreen (4:3) sequence (or vice versa). In this case, the procedure is exactly the same, except that you may only need to crop the top and bottom of the image (or left and right sides), keeping the rest.

The option to crop crops up quite a lot within Final Cut Studio*. You’ll see check-boxes and dialogue boxes with crop options all over the place throughout Final Cut Pro, Motion and Compressor, particularly when working with different kinds of media. Just be aware that in general, cropping will discard the edges of an image in favour of filling the frame.
*Sorry, I couldn’t resist that.

Tip: To crop unwanted parts of a frame, use the Crop parameters in the Motion tab. You can also feather this effect to soften it.

What if you’re not concerned about quality, and don’t have access to your Final Cut Pro system? Then turn to QuickTime Pro.

Anything you can view in QuickTime can be scaled to a different size. Unfortunately this method uses basic interpolation at best, and so the results will almost certainly be lacklustre. However, this can be a good choice to resize a lot of footage where quality is not an issue, and the more technically-minded can put Applescript to work to batch resize lots of clips without needing Compressor.

To scale footage in QuickTime Pro:

1. Open the clip (or an image sequence).
2. Select Window/Show Movie Properties.
3. Select Video Track and click the Visual Settings tab.
4. Type a new height or width (in pixels or percentage) under Scaled Size.
5. Save or export the resized clip.

Tip: QuickTime Pro can also be used to scale image files or sequences

In the next part of the series, we’ll be looking at different cropping methods.