Phantom v12

I recently shot a promo for Starz Encore using the Phantom v12 and wanted to share a few thoughts regarding this sorely under utilized camera system. First of all, what's most amazing is that it delivers excellent quality 720p HD video at a shocking 6,900 fps. For this project we were mostly blowing up glass and ceramic objects and at this extreme frame rate, it’s like you’re seeing into the inner workings of the universal laws of physics. The minute beauty of it is just incredible.

Here is the clip:

http://www.starz.com/Promotions/FearFest

The stop motion segments were shot with a Canon 40D and the rest was shot on the V12. I have some additional footage that was not used in the spot that I'll be posting eventually.

If anyone reading this isn’t familiar, Phantom is pretty much the go-to cine-style video camera for high-speed applications. Part of the reason Phantom is so useable to production professionals is because of one of my fav NYC rental houses, Abel CineTech, and their unique relationship with the camera’s creator, Vision Research. Abel’s staff has done a first rate job of taking a camera that was designed mostly with military engineers in mind and turning into something that slides seamlessly into the camera department. Just have a look at the new Phantom HD Gold for a perfect example of this.

Prior to this job, my experience had only been with the Phantom HD, the far more commonly used Phantom camera that shoots 1080p at around 1000 fps. The new HD Gold is the upgrade to the original HD and was created to rectify some of its well-known issues – most noticeably noisy, unstable blacks. Having not worked with the Gold, I was expecting the v12 to perform similar to the HD and it certainly did. When you’re shooting at 6,000 fps you can expect to encounter a few additional curveballs though.

First of all, the v12 is an incredibly light sensitive camera. I was astonished by its flexibility. Granted this was a tabletop shoot so it wasn’t like I was lighting a massive set but I had 2 5k’s going through 6x6’s with Light Grid, shooting at 6,000 fps and I was not fighting for stop. I would safely rate this camera at 640 ASA. As with all high-speed videography, big lights are essential to reduce flicker. At such high frame rates, if you use any lamp smaller than a 2k, you will actually see the light cool slightly in between our alternating current’s 60 cycles per second. Lamps bigger than 2k burn hot enough that their intensity is not noticeably diminished in between cycles – ala NO flicker. 5k’s are a good choice for such high frame rates because you can easily knock them down if you want to work with less fps. Lately I’ve been using the iPhone App, PocketLD (Lighting Designer) by software designer Michael Zinman, to help spec out lighting packages for this sort of work. It will display the photometrics for tons of various lamps from Arri, Mole, Kino Flo, etc. at any distance you input. Extremely useful for figuring out how close your light sources need to be to get a working stop at 6,000 fps. Especially when you know that your going to be exploding canisters of paint and that you really can’t be any closer than 10 feet!

The v12 has the same problem with the black portion of the video signal (pedestal) as the HD if not worse. This is the most critical aspect of working with the Phantom. You must do a CSR aka Current Session Reference aka Black Balance before every shot. Why Phantom has such an issue with the blacks, I don’t know. I do know that if you don’t do it, you can count on weird blocky banding and discoloration on your shot that will no doubt render it totally useless. The nice thing is that the v12 has an internal capping shutter so you can do the CSR remotely and not have to cap the lens unlike the HD (pain in the ass!) Love that feature. I did notice that the higher the frame rate, the worse the problem with the blacks became and sometimes they would start to give out towards the end of the shot. This is not something I’ve encountered with the HD and is problematic because there’s really nothing you can do to remedy it except trigger the shot so that the important moments are stored in the beginning of the buffer.

Other issues:

Blue Channel Weirdness. This seems to be a real CMOS issue and the Phantom camera is no exception. No matter how many times you black and white balance, it seems that blue channel is always a little boosted. We were doing some shots with a black curtain background that was very slightly reflective and that was all it took for the blue channel to go haywire. The whole image went completely blue and doing black and white balances did nothing to remedy. I switched the curtain out for black duvetyne with the matte side to camera and that seemed to fix it. Phantom cannot deal with black so if you’re using a black background, make sure it is as close to non-reflective as you can get and keep spill off it!

White Clip: The director had a few shots he wanted to get on a seamless white background so we lit it up and put the whites at around 100 IRE, not even clipped, and that seemed to overload the sensor. The image was taken over by horrible banding that black balancing had no effect on. It wasn’t until the white was at just under 80 IRE that a black balance removed the banding.

CMOS Smear at very high frame rates: On some of our more reflective objects, at very high frame rates, I noticed some smearing in the highlights. Any highlight that clipped or approached clipping had a little smear to it. The bigger the highlight, the greater the smear. This must tie in with the aforementioned white issue. There is no white protection or KNEE on the Phantom camera so when the whites go, they go hard and apparently make the sensor more vulnerable to the well known issues related with CMOS sensors. My remedy was to just to keep the specular highlights under control with lighting. Honestly it wasn’t such a huge issue but it was something that I noticed.

All and all the v12 is incredible technology and I cannot wait to work with it again. Blowing stuff up at 6,000 fps is why I got into this business in the first place :)

Apertus Open Source Cinema

Here's something interesting I recently stumbled on - a public project to create an open source software and hardware camera system based on an Elphel 353 High Definition Closed Circuit Network Camera. That's right, a surveillance camera. Turns out it makes pretty nice pictures so a few guys got the idea to find a new application for it.

From the Apertus site:

"Our goal is to create a powerful free and open cinema camera that we as filmmakers love to use. The idea of using an Elphel camera for this particular purpose was born in 2006, found many followers over the years and ultimately resulted in this community driven project entitled "Apertus" and this website."

This is the camera:

and here are the specs - cliff notes style (from their site):

Sensor:

The camera uses an Aptina CMOS bayer-pattern sensor with an optical format of 1/2.5" (5.70mm x 4.28mm) and a native resolution of 2592x1944 (5 Megapixels). It features a 12 bit ADC and supports: region of interest, on-chip binning and decimation. Aptina claims that the chip has 70db of dynamic range at full resolution and 76db when using 2x2 binning.

Lens Mount:

The camera has a standard C-mount but ships with an adapter ring that allows to mount CS-lenses as well. More adapters are in planning stage.

Resolutions:

The recording resolution can be freely adjusted to anything starting from 16x16 to 2592x1944 in 16 pixel steps. This includes Apertus AMAX (2224x1251), Apertus CIMAX (2592x1120), 2K (2048 × 1536), Full HD (1920x1080), HD (1280x720) and of course all lower resolution SD formats like DV PAL, DV NTSC, etc.

The lower the resolution the higher the maximal possible framerate. At the full sensor size (5 million pixels or 5 Megapixels) the maximal frame rate is 10 fps in normal color mode and 15 fps in JP4 RAW mode. JP4 achieves higher framerates in general as some camera internal calculations are skipped and need to be applied later in postproduction (like debayering/demosaicing).

Because this project is essentially a public effort, it's a little difficult to ascertain what stage of development it's in and even how involved the Elphel company is. It's a great idea and I love the DIY spirit. The main Apertus site doesn't disclose much so if you're interested learning more, there are a number of sites to read:

Apertus Open Source Cinema Page

Elphel 353 in a nutshell Wiki

Elphel 353 HD Cinema Camera Development FAQ

Elphel, Inc

Elphel Wiki