Monday 12 November 2012
Video assist, dailies and 'looks' in digital movie-making
I keep calling them movies, not films, and movie-making, not film-making because some new movies in India are being shot on digital mediums - Canon HDSLRs, Red, Alexa, Sony and others. No film used, means new methods, new workflows. The concept of 'video assist' and 'dailies', too assume a somewhat different approach.
Many if not all of these mediums shoot in a 'color space' that's not 'normal', also called 'Log' - LogC, S-log, RedLog etc. And they shoot at a high resolution - at least 1920x1080 HD, going up to 5000+ pixels across, or 5k. While shooting, these cameras output HD video out of HD-SDI or HDMI connectors.
So, for video assist, you need no longer use the old 'clamshell' video recorders, VHS recorders, or DVD recorders. But still, in India many a digital movie camera is rented with a DV recorder or 'clamshell'. This recorder only records SD video, 720x576 DV-PAL. So the camera rental company sends out a set of converters - to convert from HD to SD and SD to composite.
So one of the first irritants in shooting HD is that while the shot is being taken, one sees a beautiful crisp HD image. But afterwards, the playback after the take, comes out as a blurred composite video SD image. Some people on set cannot see any difference so they live with this. But most cinematographers can, and it's definitely bugging.
The other factor is color space. These camera output Rec709 (or, 'normal colour') video while shooting, but on the memory card that records in camera, they record an enhanced dynamic range image called Log - LogC, S-log, Red log etc. And that's what goes for editing.
A log image is a specially 'adjusted' image with what appears as the contrast turned down. This permits greater adjustments in post. But visually it looks dull and uninteresting to watch. RedMX, Red Epic, Alexa, Sony F3/F23/F35/F65 and some others can shoot Log, while Canon and Nikon HDSLRs shoot normal linear video.
Arri has a good explanation on Log video here...
So, there are two issues here - one is seeing a crisp image while shooting, on set, and being able to play back that image to review a take. And the other is providing this clean image for editing, so throughout the post, people get to see a good approximation of what the final movie will look like. And they won't freak out when the Cinematographer tweaks color and brightness while doing the color grading.
For the first issue, most of these Log shooting cameras provide a Linearized picture out of their monitoring HD-SDI and/or HDMI ports. So you connect that to an HD monitor and you've got a good clean HD image. To be able to review takes, you can play them back from camera and get a correct image too. But using the camera for playback that means the camera is in use even after the take and cannot proceed to the next shot.
A better option for HD review is to use a small HD video recorder. Many models exist, and some camera rental outfits have begun sending out a Aja, or Convergent recorder.
For the issue of clean dailies, one needs to engage a person or post house that will take your camera files, process them intelligently, and apply the correct look-up-tables, and output files that are identical to the original as far as file name, timecode and folder structure is concerned. Else you end up with files that look great and can be edited, but after the edit, the color grading cannot relink back to the originals.
In India, many a camera rental houses have dabbled with the creation of dailies. Since they have no background in post, they often use older systems, pirated software, and improperly adjusted monitors. And worst of all, use untrained FCP newbies to do these conversions.
I get many such complaints where the converted files have changed names, or timecode missing so the editor edits away and when its time to do DI, EDLs don't match, time is lost, anger, frustration. None of these change the cost of DI, of course, so producers don't bother with this stuff.
Some of the larger post houses have also dabbled with creating dailies too. They don't make obvious mistakes, but many a post house in Mumbai are using 5-year old systems for this, so they too take time. So dailies get delayed, and sometimes get dropped altogether. And in most post house in Mumbai there are so many commercial bookings that this free fund dailies effort gets shelved back in the calendar.
So, I've been doing daillies for a couple of movies. This began as a help for some friendly cinematographers. But over the past months, it's grown into a full-fledged dailies setup that I have at Andheri in North Mumbai. I create daillies that duplicate the look of the monitor on set. I also have a procedure in place where the cinematographer takes stills with the movie camera, color grades these on his laptop and provides them to me s a template to make dailies with so that the editor, director, and others get to see a cinematographer approved image.
Since I have an editing background, I will ensure complete timecode accuracy with dailies. As a bonus, I make dailies that take up one-third to one-tenth less space than the original camera rushes, and do conversions that are ready to use, with no import time, even for Avid Media Composer. Direct use media files for FCP and Avid.
My company Post BlackBox handles the data wrangling, backup, archive and post workflow for many movies here in India. So it's really easy for us to insert the dailies as part of the workflow. For some of our clients we have also sold full HD, video assist recorders which too, are great for dailies.
I am now in the process of creating a laptop based, wireless HD video assist cum dailies solution on set. In a way that the cinematographer can adjust colors while shooting but still record uncorrected footage. The dailies will carry this correction and everyone in the chain sees a DoP approved image with few or no surprises in DI.