Homeschool Dropouts Production Notes
Posted: October 27, 2009 at 12:38 pm, by Isaac
A common idea in modern journalism is that for a documentary to be “fair,” its creator must have no biases about the subject in question. Even if this were remotely possible from an ideological standpoint, the filmmaker would still have to know nothing and care nothing about the subject or message of his film until its completion. It is a ridiculous concept.
As many readers know, the Botkin family is extremely pro-home-education, and has been since the early ‘80s, and so when we began work on Homeschool Dropouts in August, we were already familiar with the history and current state of home-education movement.
Pre-Production
We had already discussed many of the issues that we wanted to focus on in the film with several homeschool graduates and homeschool leaders, so choosing our interviews was very straightforward. Since we were also familiar with the positions that our interviewees would be representing, we had a pretty clear outline for the script before we began shooting.
Act one makes the case that a problem exists within the home education community – the second generation is not fully supporting their parents’ vision – and provides historical context for this development. The second act describes this problem and its causes in more depth, and the third act explains how and why the problem must be solved. Simple, obvious, and hopefully a clear and concise way to present the material.
After shooting all of our interviews, we transcribed the strongest segments (Adobe Premiere CS4’s new auto transcription feature almost worked, but not quite), and began to organize the clips. Despite already having a clear direction for the film, the material we got from the interviews suggested and provided many new points, and so the script was reordered and adjusted.
Documentary filmmaking blurs the lines between production and pre-production, since lots of the rewriting can occur during and after most of the shooting. Once we had selected the best material from the almost seven hours of interview footage, we began writing interstitial segments to tie everything together, and filmed all the Botkin children delivering his or her lines. In future, we may try to have fewer hosts.
Post-Production
Since the film was basically edited at the script level, it was a simple matter to just drop the appropriately trimmed files into the Premiere timeline. The only complicating factor was maintaining sync between the A and B cameras and the externally recorded audio of the interviews. The standups, shot on a single camera with onboard audio, was easier to manage.
A lot of our outdoor shoots had background noise that we needed to remove. Rather than clean and tweak the finished audio of the final edit, we decided to process all the audio we had captured. This way, we would be editing with the final audio, and when we locked the edit, the bulk of our audio mastering would already be done.
I set up a number of scripts in Adobe Audition and we basically batch-processed everything overnight – noise reduction, normalizing, multi-band compression, and a little EQ, all customized for each setup, but not each individual file. At the beginning of a project, there’s much more time for rendering things than at the end, so even though I ended up processing several hours of audio instead of 50 minutes, it was a more efficient workflow.
We did the same with color correction. Since nearly all of the footage was beautiful right off of the camera, we went for a very minor grade, with very few adjustments which rendered quickly. I decided to render corrections to all the footage, rather than just the selected files. This meant that any last minute adjustments to the edit wouldn’t require additional grading and rendering.
That bought me time to work on the cover design and DVD menus right up until the deadline even as we continued to polish the edit. This was our first project to use Adobe CS4, and we used all the pieces; Premiere for the edit, After Effects for the graphics and color correction, Photoshop for the cover art, and Encore to build the DVD.
Even though Cineform’s real-time engine wasn’t functional in CS4 yet, the codec is so efficient that we got real-time performance anyway. Since we had color corrected anything that needed it in advance, we never needed to render anything in the timeline until final output. Also, Premiere CS4 was rock solid stable no matter how many clips were in the bin or how many sequences were in the project.
I’m already looking forward to our next project. The quality of the 5D’s image, the speed of tapeless workflow, and the stability of the whole Adobe package made this a very fast film to complete, with just over two months from shooting the first interview to mailing off the master. It never felt like we had to fight to make things work in a technical sense (although the script was a different story).
The only things that could have drastically improved the process would be the Cineform real-time engine, which comes out November 6th, and more accurate voice recognition in CS4, which is being upgraded. It really is an excellent production package for documentary filmmaking.
Shooting and Posting on the 5DmkII
Posted: October 22, 2009 at 2:21 pm, by Isaac
As I’ve mentioned before, we shot the documentary Homeschool Dropouts on the 5DmkII in August, and posted it during September. It was a great learning experience, since it was our first time shooting video on a dSLR. Below is the worst shot from the project – all of the 5D’s image issues are visible in it. All of them can be avoided in-camera and all but one of them can be repaired in post (not counting the awkward composition).
Above is the final image as it was rendered from After Effects. Firstly, we have repaired the exposure. This was a very early shoot, before we started using the Magic Lantern firmware, and without its live histograms and zebra bars, getting the right exposure was tricky. Even though the camera only saves an 8-bit image, there is lots of room for correction, and since it comes from a 14-bit sensor, there is a surprising amount of latitude recorded.
Next, I adjusted the color. The green cast on the top of the wall is actually sunlight bouncing off the lawn in front of the porch. Since I had over-exposed a lot, and eyeballed the white balance badly, slight color changes like that were amplified, but it’s a great testament to the color sensitivity of the camera that it picked that up so vividly.
This shot also required a little bit of denoising. Even though we were using a low ISO setting, I had enabled Highlight Tone Priority on the camera. There’s some dispute as to how useful this setting is for video, and while it does provide more latitude in the highlights, it also adds some strange shadow noise. I used it on several early shoots, but I’m a little more leery of it now. I would use it with caution.
There’s also some subtle moiré pattern on Mr. Swanson’s sleeve. This is the Achilles heel of all of Canon’s video-enabled dSLRs, and it can be tricky to spot on the viewfinder. It’s also not especially predictable; note how it appears on the invisible pattern of the oxford cloth shirt, but not at all on the very pronounced weave of my jacket.
This cannot be fixed in post, but slightly adjusting the camera’s position, zoom, and/or focus will often make obvious aliasing and moiré artifacts vanish. I overlooked this issue, like all the others in the shot, because the camera was new, the shoot was hasty, and I was on the wrong side of the lens. Still, no excuse.
But enough dwelling on the worst shot; have a look at some of the better footage that we got:
 
 
All the outdoor shots were natural light with a single reflector, and the indoor shots were using available lights in the various homes rather than a professional light kit. Outdoor shots generally used Canon’s EF 28-135mm zoom lens, and most interviews used EF 50mm 1.8 primes.
Minor grading was applied to each shot, but it was extremely limited since the raw footage was so good. Some interviews got a subtle vignette, and there was a bit of levels work here and there, but most of these shots are pretty natural. I’ve downsized all the 1080p screenshots to 720 for bandwidth reasons, but it’s still big enough to see noise, any artifacts and also the sharpness that the camera is capable of.
Update:
I forgot to mention audio, or how we actually got footage from the camera into the edit. This is an important part of posting, so here’s our process:
The Canon 5DmkII records to MPEG4 files at about 48mb/s. For reference, HDV is MPEG2 at 25mb/s. MPEG4 is a far more efficient codec, so I figure that there’s actually more than twice the image data contained in twice the bitrate, but it’s not a good editing codec, so we converted everything to Cineform as we pulled it onto the computer.
The 5D also shoots 30 frames per second, which is a problem since NTSC video actually runs at 29.97 frames per second. Fortunately, Cineform automatically fixes this, conforming to the proper framerate and stretching the audio that extra 0.03 fps during conversion. We never had any sync issues once we realized we also had to stretch our external audio as well.
The interviews were recorded with a Sennheiser 100 G2 wireless mic running into a Zoom H2 audio recorder. All of the Botkin standups were recorded with that same mic running directly into the camera. Being primarily a stills camera, the 5D has crummy audio preamps, and they are by default set way too high and on automatic gain.
Using Magic Lantern, we were able to manually set the analog and digital gain at the appropriate levels, 0db and 6db respectively. With the Sennheiser receiver cranked all the way up to -6db, the audio signal was hot enough to need no real in-camera amplification, and so we got a very clean signal.
Latest Video dSLR News
Posted: October 22, 2009 at 1:27 pm, by Isaac
Several months ago I (and pretty much every other video blogger) talked about what Canon could do to improve their lineup of HD-capable dSLRs from the perspective of video production. Since then, they have added a lot of improvements, some with firmware upgrades, and some in new hardware. Here’s a quick update on where things stand today:
5DmkII – released November 2008
The pioneer. Its full frame sensor provides excellent low light performance and tremendous color reproduction, and a high bitrate MPEG-4 codec preserves a lot of image detail. However, a single processor doesn’t allow full HD out and full HD recording at the same time, making monitoring the camera difficult, and the camera is limited to 30 frames per second only. However, that will change with a firmware release expected early next year which will offer 24p and 25p, and the third-party firmware Magic Lantern enables live histograms, zebras, manual audio control with VU meters, and more.
7DmkI – released September 2009
Shoots 24p, 25p, 30p, and introduces a second processor for shooting additional framerates like 50p and 60p (when in 720p mode). With double the CPU power, it also has better monitoring options, allowing full HD output during recording, but auto-only audio is still a limiting factor. It has a new APS-C sensor which, being quite a bit smaller, has a little less sensitivity than the 5D, but allows the use of cheaper EF-S lenses (and much more expensive S35 cinema lenses). And it’s almost $1000 less than a 5D.
1DmkIV – announced October 2009
Same added processing power and framerate options of the 7D, and probably no real improvements in audio and monitoring, but it does have a brand new APS-H sensor which can see in the dark (not in low light – in the dark), and vastly reduced rolling shutter artifacts. Of course, it will be expensive. And it’s not out yet. But… it can see in the dark and there’s no jello-cam!
A couple of months ago, I bought a 5D, and I love it. It has many technical limitations, but the image quality is so good that I really don’t mind working around them. Immediately after unboxing the camera, we shot a 54-minute documentary with natural light in the space of three weeks, and I never felt tempted to reach for my XL H1.
Of course, there are also a few image limitations, but they tend to be the inevitable result of putting a video camera into a still camera body, like a lack of basic live autofocus. The aliasing and moiré patterns that can result from every-other-pixel capture exist on all three cameras, and can require a little focus adjustment to avoid. Also, the electronic iris control on certain Canon lenses can flicker when zooming.
Nevertheless, Canon’s firmware and Magic Lantern have made it a very usable filmmaking tool, especially for the price. I think that the 7D probably offers the most bang for the buck, but some documentary filmmakers could certainly use the improved low-light performance of a 1D, once it arrives.
Because I do very little still photography, the full-frame sensor of the 5D is really overkill for me, as are most EF lenses. In many ways, I would really prefer a 7D with a wider (and cheaper) selection of image-stabilized EF-S lenses, but I have to admit that the look of the 5D’s giant sensor is really hard to beat.
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