Wednesday, July 08, 2009

The end of another year

Congratulations to all who negotiated the change in rooms - the big plasma in our new temporary venue made all the wandering around worthwhile! And relayed apologies again from Darren at Matrox for their last-minute non-show due to technical problems - they WILL be back, they promise, with a demo running 'on all cylinders'.

My demo this month was a tale of four keying methods for green screen: all working on some (non-ideal!) HDV material - a realistic challenge for many of us.

First off, to only moderate applause, is the FCP 'built-in'. Provided you choose correctly between the Green Blue Effect, and the Green AND Blue Effect, the latest version provides a graphical interface for eye-dropping colour and adjusting chrominance / saturation / luminance keying levels.

With a little more tweaking than I did on Monday night AND with the 'Color Smoothing Filter' enabled (!) the key looks like this:

There's noticeable fringing / stepping just about visible on the uploaded pic - on the edges of the arms especially - which is the result of trying to key off HDV, a 4:2:0 standard, meaning reduced chroma definition.

I'd rate the key as OK - but difficult to get good quality all across the frame, meaning I'd have to do extra mattes with garbage filters for uneven backgrounds.

Next up was the keying effect included with Motion - Primatte. The matte produced here was very good from the first 'eyedrop' - again you can see the interlace-like stepping caused by the lack of chroma resolution. (The footage is progressive, by the way, and we're viewing results obtained on a ProRes timeline). There are controls to soften the matte, which loses the jaggies, but makes for problems with details such as hair, of course.

Verdict so far - better keying from Primatte, but with the hassle of round-tripping to and from Motion, which isn't always practicable, especially on a project with lots of short keyed sequences, which may need recutting (frequently).

Two other contenders, one newly re-launched, and another established name:

The new kid on the block is 'Chroma Key Studio' from Boris. There's more than a simple key here, the package adds extras such as a wrap-around edge based on the background picture. There's also an option for working off a 'plate' - for locked-off cameras - a 'background only' shot used to generate the key (in the same manner as iChatAV now offers).

The grab here shows the matte with a little softening applied, which helps the jaggies - too much and the hair detail will disappear, of course.

And finally, one that I'd forgotten about until a chance conversation with Matt at the Supermeet last week - dvMatte Pro from DVGarage. This is another FCP effect (actually an FX plug-in), with a more complex keying system to set up - with two droppers for high and low background levels. Plus the now familiar edge lighting and matte softening.


This filter I found to be extremely easy to use, and gave results as good as Primatte in Motion (which until now I'd considered the gold standard for FCP keying).


For ease of use, I'd rate the Boris Chroma Key studio and dvMatte Pro joint equal. The built-in FCP key is fiddly and didn't give as clean or as adjustable an end result, and though the Primatte key is fine, sometimes you just want to keep in one App, on the timeline.

Both the Boris and dvgarage products are downloadable as trial versions
here for the Boris package. Note this also offers real-time keying for studio application.
here for dvMatte pro.

I ought to say - don't judge the quality of any of these keyers on my rough-and-ready efforts for the demo purposes. But at least they have the benefit of equal treatment and attention.

And while you're downloading, there's another filter tip from Monday, thanks to Jason.

It's new to me, and it's free - in fact one of many freebies on the same website. It's known as the Captain's blowout fixer, and is a clever repair, no a very clever repair kit for overexposed footage, written by Patrick Sheffield, who would appear to be a Shake wunderkind, and a generous one as well. The fixer works by abstracting detail from other colour channels (eg if Green is blown out, there's a good chance that Red isn't) and substituting. It shouldn't work, but it does.

The download page has some wonderful Technicolor simulators - great fun to see.
Here is the site.

And, apart from Richard's promised sumup of his DVD experiences, that's it for Year 5 of the wefcpug. See you at the 5th birthday big bash. There will be blog updates over the Summer (who needs vacations) and maybe a podcast too.