CoreMelt offers a number of GPU-accelerated plug-in sets for Final Cut Pro, Final Cut Express, Motion and After Effects. One powerful collection is CoreMelt Complete V2 (“v-twin”), which is currently up to 200 filters, transitions and generators. However a very cool, separate filter is their Lock & Lock X stabilization plug-in for Final Cut Pro. The original Lock & Load filter was updated to Lock & Lock X (a free upgrade for L&L users) shortly after NAB2010 and gained a significant new feature – Rolling Shutter Reduction.
Rolling shutter artifacts – the so-called “jello-o-cam” effect – have been the bane of CMOS-sensor cameras, most notably the HD-capable DSLR still cameras. The short answer for why this happens is that objects move in place during the time interval between the data being picked up from the top to the bottom of the sensor. The visual manifestation is skewing or a wobble to the image on fast horizontal motion or shaky handheld shots. CoreMelt’s Lock & Load X is designed to be used for both standard image stabilization, as well as reduction of these artifacts.
Final Cut Pro already includes a very good, built-in stabilization filter in the form of Smoothcam – a technology inherited from Shake. So why buy Lock & Load X when you already own Smoothcam? Two answers: speed and rolling shutter artifact reduction. Generally, Lock & Load X is faster than Smoothcam, although this isn’t always a given. CoreMelt claims up to12 times faster than Smoothcam, but that’s relative. One important factor is the length of the clip. When Smoothcam analyzes a clip to apply stabilization, it must process the entire media clip, regardless of how long of a clip was cut into the sequence. If the media clip is five minutes long, then Smoothcam processes all five minutes. Fortunately, this can proceed as a background function.
In contrast, Lock & Load X only analyzes the length of the clip that is actually in the sequence. If you only used ten seconds out of the five minutes, then Lock & Load X only processes those ten seconds. In this example, processing times between Smoothcam and Lock & Load X would be dramatically different. On the other hand, if you used the complete length of the clip, then processing times for the two might be similar. I’m not exactly sure whether Lock & Load X uses the same type of GPU-acceleration as the V2 filters, so I don’t know whether these processing times change with the card you have in your machine. I’m running a stock NVIDIA GeForce 120 in my Mac Pro, so it could be that an ATI or NVIDIA FX4800 card might show even better results with Lock & Load X. I don’t know the answer to that one, but in any case, processing a 1920 x 1080 ProResLT clip that was several seconds long took less than a minute for both stabilization and rolling shutter reduction.
When you compare the stabilized results between Smoothcam and Lock & Load X, you’ll generally prefer the latter. Most of the time the filter doesn’t zoom in quite as far and if you leave some movement in the image (such as with handheld shots), the “float” of the image feels more natural. However, there are exceptions. I tested one clip with a hard vertical adjustment by the cameraman. At that point, Smoothcam looked more natural than Lock & Load X, which introduced a slight rotation in correcting that portion of the clip. Another difference is real-time performance. On my machine, Smoothcam left me with a green render bar and Lock & Load X was orange. In FCP terms, this means that the unrendered Smoothcam clip played without degraded performance, while the Lock & Load X clip dropped frames. Once rendered, there’s no difference, of course, and render times were similar between the two. Again, this result might differ with another display card.
Rolling shutter artifact reduction is not unique to Lock & Load X, but as far as I know, is currently only available in one other, more expensive filter from The Foundry. In CoreMelt’s implementation, you must select the shutter coefficient, which is based on certain camera profiles supplied by CoreMelt with the filter. If you are working with Canon EOS 5D Mark II or EOS 7D footage, simply pick the camera, run the tracking analysis and you are done. You can choose to stabilize, reduce rolling shutter artifacts or both. In many cases, rolling shutter reduction is very subtle, so you might not see a massive change in the image. Sometimes, the filter simply corrects minor vertical distortions in the frame.
One application I find quite useful is with handheld shots that are intended to look like Steadicam shots. Lock & Load X does a nice job of steadying these shots without losing the natural “float” that you want to keep in the image. The “before” version might look decent, but when you compare the “after” version, it is definitely the preferable image. In order for Lock & Load X to do its magic, it has to blow-up the image slightly, so that the picture fills out to the edges of the frame This is true of any stabilization filter, including Smoothcam. Lock & Load X does this expansion within the filter and doesn’t change motion tab size values. The filter includes a “smart zoom” feature – intelligently resizing the image throughout the clip so that the least amount of blow-up is performed at any time. For a subtle stabilization, like the handheld shot example, Lock & Load X will typically zoom the image between 7% and 12% throughout the length of the clip. Thanks to the processing used, the quality of the rendered clip will be better than if you had zoomed in 10% in FCP’s motion tab.
CoreMelt’s Lock & Load X is a specialized filter. When you have the need for this function, it’s hard to beat. Clearly a new selling point is rolling shutter artifact reduction. Pro video cameras aren’t immune to the effect, however, since even a Sony EX uses a CMOS chip. But it’s a big factor for the HDSLRs. These cameras will continue to be the hot ticket for a while, so Lock & Load X becomes an indispensible tool for editors posting a lot of Canon and Nikon projects.
©2010 Oliver Peters