As we've discussed in many issues of MFM, the best audio always trumps the best visuals. (In fact, recently I saw two no budget films with gun fight sequences: one that had good VFX but subpar sound effects and the other that had top notch sound effects and NO VFX at all. Despite the lack of VFX, the second film was believable, whereas the first film was not.) With that said, so long as proper care of audio is being taken, it is still within all of our hearts to have the best looking visuals that we can. While the proper camera operator is the most important part of that equation, followed by the lighting technician, the actual camera itself should fall into the third rung of importance.
With that said, I thought I would relay some of my own looks at cameras in the light of a specialty effect that is finally becoming more available in low-budget cameras: variable frame rates.
While there are many types of variable frame rates, the only ones that are really necessary in camera are true overcrank effects. "Overcrank" is a term that comes from traditional film acquisition in which camera operators would use a special handle to actually crank film through a camera. If twisted the crank faster than normal, more frames would be exposed per second than normal. When the film was played back at normal speed, the overcrank sections became slow motion. (The converse was also true. If the operator "undercranked" the camera, it would play back at fast motion.) With the invention of mechanized cameras, mainstream and specialty companies began creating amazing film cameras for Hollywood that could record faster and faster frame rates. (John Woo was known for shooting parts of his dynamic gun battles at 200 fps!) When digital became more and more popular, faster frame rates could be achieved than film could hold up to. The recent Academy Award winning film, The Hurt Locker, used the Phantom HD camera which can achieve a blistering frame rate of over 1000 frames a second! (Shows like Top Shot and MythBusters use cameras with similar capabilities to show actual muzzle blasts and explosions that would escape the human eye even at common slow motion speeds.)
Obviously, these sorts of speeds are well outside the hands of most low-budget filmmakers, both due to the cost of the cameras and the massive light requirements. However, as I began to work on the sci-fi/action franchise, Depleted, which we are producing at MFM, I really wanted to see how close we could come to the polish of these sorts of overcranked cameras on a microbudget. (For those of you who have been following the Depleted saga, we are creating this post-apocalyptic action film on a $30K budget, so we've got squeeze the most bang from our buck at every stop along the way.)
The first thing we had to consider was how much we wanted to do practically vs. in post. We were already planning to do many of the special effects in post, having first gotten familiar with Per Holmes' excellent training, Visual Effects for Directors, so we acquired the footage correctly, and then learned how to use Video Copilot's Action Essentials 2 assets correctly, so doing some of the slow motion in post was definitely worth considering. The practical truth is that you can make a compelling slow motion effect using RE: Vision's Twixtor, but it works best if you're only doubling your frame rate in this program. As such, for a sharp looking slow mo that can approach 120 – 240 fps in post, you want to find a way to acquire the image at 60 fps to 120 fps.
Before plunging into the feature without more hard data, we wanted to shoot a short prologue called 'Depleted: Day 419'. This would give our fans something to start getting excited about while we worked on the feature and give us ironclad information about the best way to approach the feature from a technical perspective. For our first foray, we decided to use the Panasonic HVX200 which is able to acquire 720P images at variable frame rates up to 60 fps. This was then plugged into a Redrock M2Encore 35mm lens adapter which would permit cinematographer Nate Eckelbarger to get a truly film-like depth of field using his amazing collection of 35mm SLR lenses.
In concept, this was great. In practical use, there were mixed results. While the M2Encore didn't cut too much light from the camera, the HVX200 is extremely light hungry because it only has a 1/3" imaging sensor which it packs an HD image on. (To give you a comparison, most professional quality HD cameras use a 2/3" to 4/3" sensor, which gives them potentially double to quadruple the light sensitivity.) When you then shoot at 250% the speed of the normal 24 fps, you can potentially cut down the light sensitivity by around half, especially if you increase the shutter speed. In addition to the amount of time that needed to be spent on lighting, there was the fact that the entire system was large, heavy, and unwieldy. (In fact, it often felt like the shooting of the film was as science fiction as the film itself, as the camera rig looked suspiciously like a futuristic matter canon!)
So, while the rig worked great for a four day shoot, it wouldn't be the ideal setup for a three week shoot next year for the feature in which we had to move much faster. As such, we began to think about a couple of different solutions that might make sense. Obviously, the RED Scarlet would be a great camera to use with it's split the middle 2/3" sensor and 120-150 fps recording speed, but as there's still no delivery date on it and their website stats haven't even been updated since last year, we can rule that one out of contention.
The first option was using an acquirable higher speed camera for any insert slow-motion shots. This is the way Hollywood operates, shooting 90% of the film with an A-Camera and then shooting the 10% of slow mo or FX cameras with a specialty rig B-Cam. While Phantom HD cams would be too expensive to rent for this, if all the slow-motion shots were lumped together renting a REDOne wouldn't be a bad way to do this, as the REDOne can shoot 2K imagery at 120 fps with a full frame sensor and is pretty affordable, although it is extremely prone to overheating. If we want an even more affordable way to do this, a little known feature in the Sony HVR-7ZU can come to the rescue. According to MFM contributing writer Andy Yardy (who owns two of these cameras), the 7ZU has a special buffer recorder which will allow it to record 120 fps for 12 seconds at a time at 1080P resolution. Additionally, the camera has replaceable lenses, so we could more closely match your optics to that of the A-Camera if we're using a Redrock 35mm adapter or a video DSLR. Unfortunately, it too has a 1/3" image sensor, which means we'd have to really crank up the light if we want to expose the 120 fps 1080P image properly.
If such a situation is pursued, we'd probably use a video DSLR with a full frame sensor and good image quality, such as the Canon 5D Mark II or the Nikon D3-S, in a Redrock DSLR Shoulder Mount system as our A-Camera to increase our speed of shooting when not doing effects shots. (Obviously, use of video DSLRs requires audio to be recorded separately, which isn't much of a problem if the clackboard is used properly, plus separate audio recording further detangles the camera from additional tethers.) The only major downside in this situation is that the different cameras, especially from different manufacturers, can yield different color casts which would need to be adjusted in post, a potential problem due to the greater compression present in both the HDV compression of the 7ZU and the Quicktime compression of the video DSLRs.
The other option to consider, which wouldn't require as much post-adjustment, would be a single all-around camera that can give us a decent depth of field but is also capable of doing overcrank effects. In the past, this would have gotten way out of the price point of low-budget filmmakers, requiring looking at the Varicam or similar packages. However, Canon recently released the 7D, a video DSLR which is able to shoot 1080P at 24 fps, but is also able to shoot 720P at 24 fps and 60 fps. The camera is actually released to a consumer market at an extremely low price point (between $1500 - $1800), but has a smaller sensor size than the 5D Mark II, roughly the size of 16mm film (or, in digital terms, around 2/3"). This still permits twice the depth of field of the unmodified sensors in the HVX200 or the 7ZU, as well as a greater potential for light sensitivity. Eventually Canon will likely release a full frame pro video DSLR with these options, although no release dates have been stated, so it's nothing we're banking on for this film. (Nikon will also likely enter this foray eventually, which I would love to see.)
To add to the mix, a recently announced camera from Panasonic might prove to be a major game changer: the AG-AF100. Announced at NAB this year, this is a legitimate HD camera (as opposed to a DSLR with video capabilities) designed to give low-budget filmmakers the full frame shallow depth of field which have required a lens adapter or a full frame video DSLR in the past. This is because they've created a special micro 4/3" CMOS sensor which is designed to allow you to use almost the full surface of a 35mm lens with most of the shallow depth of field remaining intact and should be potentially much more sensitive to light than the HVX200. The camera is designed to look like a traditional motion film camera, but still has all the digital amenities in place, like dual XLR plugs and the like. Its recording options are almost identical to the HVX200, including recording 1080P at 24 fps and having 720P overcrank options up to 60 fps, but it will record to the night-and-day cheaper SD and SDXC cards vs. the HVX's P2 cards. (The only downside would be the fact that this camera uses a recording system based on AVCHD, so the color information will likely be cut in half from 4:2:2 to 4:2:0. As such, it wouldn't be the best choice for greenscreen. Of course, shallow depth of field is the enemy of greenscreen, so this wouldn't likely be a setup you'd consider for that application anyway.)
Panasonic states this camera will be available by Christmas and, as much as I appreciate all that Jim Jannard and RED do for filmmakers, when it comes to release timelines, Panasonic has a much more solid track record. While no price point has yet been released, unsubstantiated rumors suggest that it will likely be priced around the same price as the HVX200A, approximately $6K. Only time will tell!
As always, it's an exciting time to be a low-budget filmmaker! To find out more about what we end up using on Depleted, be sure to follow us at World of Depleted and both the Depletedand MFM Facebook pages!