{"id":58,"date":"2009-11-04T01:44:06","date_gmt":"2009-11-04T08:44:06","guid":{"rendered":"http:\/\/www.hd4pc.com\/techblog\/?p=58"},"modified":"2017-12-23T15:50:52","modified_gmt":"2017-12-23T22:50:52","slug":"shooting-with-the-canon-5d","status":"publish","type":"post","link":"https:\/\/www.hd4pc.com\/techblog\/2009\/11\/04\/shooting-with-the-canon-5d\/","title":{"rendered":"Shooting a Feature Film on the Canon 5D"},"content":{"rendered":"

The Canon 5D MarkII<\/a> was the first DSLR<\/a> that offered HD video capture capability worth considering as a replacement for film.\u00c2\u00a0 Its full sized sensor<\/a>, full resolution 1080p<\/a> recording, and high quality 40Mb AVCHD <\/a>compression differentiated it from all competitors.\u00c2\u00a0 I have experimented with many of the other DSLR options<\/a> on the market, but most of the projects I have worked on for the last year have been shot with the Canon 5D<\/a>, so the majority of my experience and workflow expertise has been with that particular camera, most of which I will try to share here.\u00c2\u00a0 The workflow has improved greatly as the tools have become further developed over the course of the last year.\u00c2\u00a0 While the most glaringly obvious issue was that the 5D only shot 30fps, that was acceptable for certain workflows, especially if the 5D was the only camera on a project.
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\nA much larger issue was the fact that the camera did not give the user manual control over certain important settings while in video mode, including aperture<\/a>, shutter speed<\/a>, and ISO level<\/a>.\u00c2\u00a0 The settings could not be specifically dialed in, but any setting brought about through the automatic feature could be paused or locked for the duration of the next shot.\u00c2\u00a0 Having three variables all changing made it nearly impossible to trick the camera’s auto-exposure system\u00c2\u00a0into giving\u00c2\u00a0you the\u00c2\u00a0settings\u00c2\u00a0you wanted with any level of consistency.\u00c2\u00a0 The easiest\u00c2\u00a0setting to over-ride was aperture, since this was on the lense.\u00c2\u00a0 By preventing the camera from commuicating with the lense, the automatic feature could be disabled.\u00c2\u00a0 But with no electronic communication to the lense, the\u00c2\u00a0aperture must be set physically.\u00c2\u00a0 Older Nikon<\/a> Nikkor<\/a> manual lenses were the only ones that easily adapted<\/a> to the 5D, that had physical rings for controlling the aperture manually.\u00c2\u00a0 Once the\u00c2\u00a0aperture was set, the standard practice was to point the camera at lighter or darker areas until the automatic exposure feature gave the user the desired settings, and then to lock it.\u00c2\u00a0 This process had to be repeated for each take or shot, as stopping record put the camera back into full auto.\u00c2\u00a0 Regardless, many people used this method of manipulating the camera to achieve the desired results for the first few months after its release, and I worked on a number of commercial projects that did.\u00c2\u00a0 Canon was not real excited about promoting the use of Nikon glass over its own lenses, so this was one of the first issues they fixed.\u00c2\u00a0 The 1.1.0 firmware update solved this problem by allowing the user to maunally set the aperture, shutter speed, and ISO, and keep it consistent from shot to shot.<\/p>\n

So once the lenses issue was dealt with, were left with a selection of AVCHD encoded MOV files.\u00c2\u00a0 AVCHD is a processing intensive format that does not playback or edit very well.\u00c2\u00a0 While Quicktime <\/a>would play the files, it clipped the blacks and the whites at incorrect levels.\u00c2\u00a0 16 and 235 were being stretched to 0 and 255 on decode, lowering the dynamic range.\u00c2\u00a0 This was caused by Quicktime incorrectly interpreting one of the header fields on the file.\u00c2\u00a0 The solution to this was to use CoreAVC<\/a> to decode the files when converting into a different, and ideally more edit friendly, compression format.\u00c2\u00a0 Shortly after this workaround was developed, Apple released a Quicktime update (7.6) that fixed this particular\u00c2\u00a0issue entirely.<\/p>\n

Beyond the clipping issue, there are other tricks to maximize the dynamic range of the 5D.\u00c2\u00a0 The picture style is used to control the way that\u00c2\u00a0the camera\u00c2\u00a0converts the 14bit RAW still into an 8-bit JPEG.\u00c2\u00a0 The same picture profile settings are applied to the 8-bit recorded video.\u00c2\u00a0 This allows you to do things to get the maximum detail out of the available 8-bits of color depth.\u00c2\u00a0 The first few projects I\u00c2\u00a0worked on\u00c2\u00a0that used the 5D, we used a custom picture profile that I got from Stu Maschwitz’s ProLost blog, High Gamma 5<\/a>.\u00c2\u00a0 We did a number of comparison tests, and while High Gamma 5 gave us a wider total dynamic range, for our feature film, we eventually decided to use Neutral, one of the default Canon presets.\u00c2\u00a0 Neutral gave us a file that was closer to the final look we were going for, and with only 8bits of color depth, burning in your look, at least to a degree, should result in better picture quality at the end of the day.<\/p>\n

Every file the camera records is named MVI_####.mov, with an auto-incrementing number, and no real override options.\u00c2\u00a0 That makes things simple on tiny projects, with one camera since each file has a unique name.\u00c2\u00a0 On larger projects, and ones that use more that one camera, (We usually have 15) file management can be a bit more work, to keep things straight throughout the post production process.\u00c2\u00a0 Our solution was to rename each MOV file with a unique 8 digit identifier as the new filename, and store the key to the original card and filename in a database.\u00c2\u00a0 This allows each clip to have a consistent name throughout the process, to show up on EDLs<\/a> as a tape name or clip name as desired, without truncating unique values after the 8th digit for certain formats.\u00c2\u00a0 By the time we are done ,we usually have a source MOV, an Avid MXF, and an online Cineform AVI, all with the same content and file name.<\/p>\n

Next up was the framerate problem, at 30p.\u00c2\u00a0 The first few projects I did with 5D we posted at 29.97, so the issue was solved with a simple reinterpretation of the framerate, when converting from the source AVCHD into an editing codec, and tweaking the audio .1% to match.\u00c2\u00a0 Unfortunately 29.97 footage doesn’t intercut with film very well, and won’t print back for theatrical masters either, so sometimes a 24p workflow is required.\u00c2\u00a0 For 24p projects, the conversion solution is much more complicated, involving motion compensated frame blending.\u00c2\u00a0 After extensive testing we concluded that this was best done with the Revision Effects Twixtor <\/a>plugin for AE, or using Optical Flow <\/a>in FCS Compressor on OSX.\u00c2\u00a0 Having a PC centered workflow, I favor the AE based solution.\u00c2\u00a0 With render times at around an hour per minute of source footage, it is impractical to convert all of the source footage on large projects, which necessitates an offline edit.\u00c2\u00a0 Since we don’t have timecode and keycode, relinking for the online requires a bit more creativity.\u00c2\u00a0 We have found some interesting options that are unique to Premiere Pro\u00c2\u00a0CS4, related to the way it links EDLs to existing source footage that make this much simpler than our first tedious tests, which involved\u00c2\u00a0manually rebuilding projects at 24p back in Premiere Pro CS3.\u00c2\u00a0 The new CS4 version\u00c2\u00a0can convert the TC-In on an EDL to a framecounted In-point of an existing media file, with makes the onlining of 5D footage a relatively simple automatic process after a few find-replace edits (.mov to .avi in our case) to the EDL.\u00c2\u00a0 In the future, it looks like Canon is going to support 24p recording on all of their DSLR offerings, so all of these crazy 30p workarounds will soon\u00c2\u00a0be an obselete thing of the past.<\/p>\n

Although it is much better in rough environments than most other electronics, Canon DSLRs do have their weaknesses.\u00c2\u00a0 I have operated a 5D in temperatures of 20 below zero<\/a>, and in the desert at over 120 degrees fahrenheit.\u00c2\u00a0 While we had no issues in the cold, where solid state recording has a huge advantage over tape, there are some issues at higher temperatures.\u00c2\u00a0 The camera sensor itself is a large piece of silicon, that generates a lot of heat on its own, and when combined with a high external temperature, in the worst cases is shuts off the camera.\u00c2\u00a0 You probably have to be over 150 degrees to get to that point, leaving the camera in a black metal box in direct sunlight for an extended period of time, but we have seen it happen.\u00c2\u00a0 A much more frequent problem, that is harder to detect, is that as the sensor begins to overheat, there will be much more video noise in the recorded picture, especially in the darks.\u00c2\u00a0 This is probably due to a higher latent voltage on the chip as its electrical resistance <\/a>changes with the temperature increase.\u00c2\u00a0 This has only been a problem for us when shooting with the same camera for many hours in a hot environment, and our solution is usually just to swap the camera bodies for one that has not been used in a while.\u00c2\u00a0 This obviously requires having multiple cameras on set, which isn’t always an option on lower budget projects.<\/p>\n

The last issue, that we are still finding new ways to deal with, is rolling shutter<\/a>.\u00c2\u00a0 Having a large format CMOS sensor, DSLRs are subject to rolling shutter, or inconsistencies between the top and bottom of the frame.\u00c2\u00a0 I have spent the last few months working on a project that put the 5D into some of the most intense situations.\u00c2\u00a0 As a fairly lightweight device, it is subject to more jitter and shake than a larger camera with more inertia, and with the camera moving, the rolling shutter results in the recorded picture being slightly geometrically skewed, depending on the direction of the motion.\u00c2\u00a0 We also shoot high speed objects, like helicopter rotor blades, which are known to cause\u00c2\u00a0strange artifacts<\/a> in certain instances.\u00c2\u00a0 So far we have been lucky with that, and haven’t found any of those types of issues in our footage.<\/p>\n

The type of rolling shutter artifact we are\u00c2\u00a0struggling\u00c2\u00a0with the most,\u00c2\u00a0is gunfire muzzle flashes<\/a>, especially at night.\u00c2\u00a0 In the dark, the flash blows out the imager, but the flash does not last as long as even a single frame.\u00c2\u00a0 So with the rolling shutter, the top half of a frame will be totally blown out, with the bottom part looking normal, because the flash had subsided by the time that part of the chip was sampled, or vice versa.\u00c2\u00a0 Setting the shutter speed lower than the frame rate causes it to screw up more of the frame or frames, and setting it higher causes it to narrow the flash into a distinct horizontal band in the footage, neither of which is desirable.\u00c2\u00a0 One thing we have found that helps is setting the shutter on the 5D to 1\/30th.\u00c2\u00a0 (We usually set it to 1\/50 to get similar motion plur to film shot with a 180 degree shutter)\u00c2\u00a0 With the 30p framerate, the flash either affects an entire frame, or matching parts on two subsequent frames.\u00c2\u00a0 (Bottom part of one frame, and the reverse area on the top of the next one)\u00c2\u00a0 This gives us an entire over exposed frame if we stitch the two parts together.\u00c2\u00a0 This can be hand cut back into footage that has been brought from 30p to 24p by manually selecting frames.\u00c2\u00a0 It remains to be seen if this solution can be scaled practically to our entire movie.\u00c2\u00a0 The best way to avoid this issue is to avoid recording gunfire at close range in very dark environments.\u00c2\u00a0 The farther you are from the muzzle flash, and the more ambient light there is, the less it is going to flare out your camera, minimizing the\u00c2\u00a0degree of the resulting rolling shutter artifact.<\/p>\n

So that should convey some of the challenges are in faced in using DSLRs for filmmaking, especially on large scale projects, but it is by no means an exhaustive list.\u00c2\u00a0 As the tools evolve to suit the cameras, and the cameras evolve to suit the tools, many of these issues will become much easier to solve and require fewer workarounds.\u00c2\u00a0 The AVCHD decoding issue was solved by a new release of Quicktime, the manual lense control was solved with a new firmware release from Canon.\u00c2\u00a0 The 30p conversion process is the next issue I see becoming a thing of the past, if Canon can get a 24p recording option onto the 5D.\u00c2\u00a0 I am looking forward to that day, but in the mean time I have 2TB of 30p footage, divided into 5,000 shots, to cut into a 24p film, so I have a lot of work ahead of me.<\/p>\n","protected":false},"excerpt":{"rendered":"

The Canon 5D MarkII was the first DSLR that offered HD video capture capability worth considering as a replacement for film.\u00c2\u00a0 Its full sized sensor, full resolution 1080p recording, and high quality 40Mb AVCHD compression differentiated it from all competitors.\u00c2\u00a0 I have experimented with many of the other DSLR options on the market, but most […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10,11],"tags":[40,44,24,45],"_links":{"self":[{"href":"https:\/\/www.hd4pc.com\/techblog\/wp-json\/wp\/v2\/posts\/58"}],"collection":[{"href":"https:\/\/www.hd4pc.com\/techblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hd4pc.com\/techblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hd4pc.com\/techblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hd4pc.com\/techblog\/wp-json\/wp\/v2\/comments?post=58"}],"version-history":[{"count":10,"href":"https:\/\/www.hd4pc.com\/techblog\/wp-json\/wp\/v2\/posts\/58\/revisions"}],"predecessor-version":[{"id":566,"href":"https:\/\/www.hd4pc.com\/techblog\/wp-json\/wp\/v2\/posts\/58\/revisions\/566"}],"wp:attachment":[{"href":"https:\/\/www.hd4pc.com\/techblog\/wp-json\/wp\/v2\/media?parent=58"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hd4pc.com\/techblog\/wp-json\/wp\/v2\/categories?post=58"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hd4pc.com\/techblog\/wp-json\/wp\/v2\/tags?post=58"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}