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Microphone for reference audio
  • I will be booming sound and occasionally using lavaliers for my next project. I have a clapper board for syncing, but I also use plural eyes. I need a low noise microphone that will allow me to get strong reference audio. None of the scenes will be going over 4 minutes of continuous shooting. They will be a mixture of interior and exterior locations.

    The microphone will be mounted on the camera rig/cage above the camera and plugged either directly into the camera or into a fiio pre-amp then the camera body. I am really hoping to avoid latency issues, so please keep that in mind. I am seeking microphone and cable suggestions as well as your preferred options for that setup.

    Options:

    1. Microphone plugged into Camera
    2. Microphone plugged into Pre-amp then camera.
    3. External recorder (Zoom H1/Tascam DR-05) used as a line pass through.
    4. Your ideas.
  • 24 Replies sorted by
  • If you need reference audio all you need is mike plugged in camera.

    Just get on the topics about on camera mikes, cheap chinese also will do.

    Best is to choose sensitive mike (at least one that have signal boost switch).

  • Not sure exactly what this mic is for, but if you are concerned about latency you want something that has no AD/DA conversion, just an analog mic that you can plug into your camera, preferably with its own power source. As V says, an inexpensive one will probably do fine.

    There is the Sennheiser MKE400, it has mixed reviews, good things are it is tiny, runs for a long time on one AAA battery and is unusual in that it has a very good signal to noise ratio--that is, not much hiss at all, depending of course on how the gain rider in the camera interprets spaces between strong signals. A lot of people use Rode video mics as well. I record my audio separately (and so should you) but I use the 400 as a backup on a couple of cams in case something happens to the main audio rig. It gives a clear signal to use in syncing the audio in post, that is, the is a better delta on the wave form at the start of the sound. But a cheap mic would be almost as good, you would just get a trace more background noise.

  • I think the camera's built-in mic will be sufficient for PluralEyes syncing. At least test it before you go buying a new mic.

  • If the camera is anywhere near the talent, PluralEyes 3 will easily sync the whole thing. That's with my GH2s of course. Haven't used PE with my BMCC yet though.

  • My experience with Plural Eyes is that it is better to get the sync mic closer to source so that the timing is the same and the signal peaks are similar. I have lost sync or had poor offset due to mic to camera distance.

  • Sennheiser ME-66 excellent microphone at a reasonable price.

    http://www.avisoft.com/tutorial_field_recording.htm

    Tascam DR-680 excellent recorder at reasonable price.

    http://www.avisoft.com/recordertests.htm

    Best Regards

  • I actually use Azden SMX10's for reference audio on cameras B/C and everything else goes into either the Zoom H4N or Tascam DR680 then into camera A for syncing. I only use the audio coming into the cameras for syncing purposes and would not use it for anything else.

    @Mckinise How many cameras are using? Also do you have a budget that you are working with in terms of the microphone recorder etc.

  • Camera: Gh2, G6

    External Recorder: Tascam DR 40

    Plug: GH2 2.5mm (3.5mm Adapter) G6 3.5mm

    Microphone: AT835ST

  • If you are just using it for syncing with Plural Eyes, it doesn't matter so much since Plural Eyes will not account for either the offset in the camera or the distance, so it will be plus or minus one frame, typically, which is not that big a deal, although if you look closely you will see it. Most people don't care if their audio is a bit out of sync. If you are going to the trouble to hook up a mic, it should be decent enough to use in a pinch.

  • I usually use plural eyes for initial sync and then manually check. I am trying to be a bit more precise.

  • @Mckinise

    I need a low noise microphone that will allow me to get strong reference audio.

    Audio-Technica AT897

    http://www.bhphotovideo.com/c/product/400801-REG/Audio_Technica_AT897_Shotgun_Microphone.html

    Sennheiser MKE-600

    http://www.bhphotovideo.com/c/product/891475-REG/Sennheiser_MKE_600_Shotgun_Mic_with.html

    Various Adapters

    http://www.bhphotovideo.com/c/search?Ntt=Panasonic+GH2+cable+sescom&N=0&InitialSearch=yes&sts=ma&ipp=100&Top+Nav-Search=

    GH2 Specific audio adapter

    http://www.bhphotovideo.com/c/product/755857-REG/Sescom_LN2MIC_ZMGH_MON_3_5_Line_to_2_5.html

    Once again this comes down to personal preference for the microphones, but you specifically stated that you want low noise microphones for reference audio. You could also use the "Rode VideoMic Camera Mounted" shotgun microphones but those are not as good as the 2 microphones listed above in terms of noise floor. The Rode Video Mic is a lot easier to setup but for better quality I would opt for the MKE-600.

    The good thing about this setup is that you would have 2 really good shotgun microphones including your AT835ST. I only use the Azden SMX10 microphones because I had them laying around, if I had to purchase other microphones for reference audio (based on low noise floor) I would purchase the MKE-600's or the AT897's. This is the route that I would go because it allows the most flexibility down the road with very good sound quality.

    I have 2=CAD-E70's and a LAV that I use for indoor use. The CAD-E70's look just like the Superlux S241's and sound great and from what I read I think they are manufactured at the same plant. I picked them up from B&H for $100.00 each this is really good deal because they come with both the the cardiod and omnidirectional capsules. This swayed me over from purchasing the Superlux S241's, anyhow just sharing with you to give you another option for recording indoors.

    Side Note on paper the Superlux S241's have slightly better specs then the CAD-E70's, but if you look at the reviews on B&H everybody seems pretty with the CAD-E70's including myself ;-)

    Best Regards

  • I'm with with @balazer, the internal mic is pretty good for reference mic. If its used outdoors just glue a little fur around the mic holes with a removable surface adhesive. This is my GF2 but I also have same on my GH1 and GH2s. I sync off them all the time and usually the audio from them is good as backup or ambiance when mixed.

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  • @Rambo great photo. @Mckinise if you want it precise use a clapper.

  • A tip for those manually syncing after plural-eyes: best way to get an accurate sync is to pan reference (GH2) file hard to one side then the boom/lav file hard to the side opposite your reference; Lock your reference audio so it can't accidently be moved and start nudging your boom/lav during playback (must listen through headphones) to sync up with reference file; make sure both tracks are playing back at approximately the same volume; as you get closer to perfect sync you will hear the audio move from one side of the stereo spectrum (the side with the earlier wave file) to the middle then cross over to the opposite side. When the audio is dead center, your files are sync'd. This only works with mono files; if your GH2 reference audio is stereo - which it will be if you're using the camera's internal mics - you'll need to split it into two separate mono files or bounce down to a mono file.

    NB. This has to done in a DAW or program that will let you move the audio at smaller increments then one frame.

  • @spacewig that will only sync it to the audio of the cam, it won't precisely sync it to the video. That's why the clapper works so well. If you measure the offset in the cam, you can dial that in later but clapper is faster.

  • @Rambo That's probably the coolest DIY solution I've ever seen.

    +1 @DrDave Clapper always best move.

    There are many free slate and clapper apps for iphone and android phones available. I use one, works well. Or just clap hands in a pinch.

  • @DrDave Correct. But good for those who didn't have clapper and who weren't filming 20+ feet away from the actors while the boom was on them. I think a few ms is negligible

  • @spacewig Yup, a few ms is small. But if you are super picky, the offset in the camera is usually--but not always--1/3 frame, or 14ms at 24p. That's because a lot of camera manufacturers assume that you will not be one cm away from the source. You might be, of course, and if you are making a video of an ant you could capture it's tiny skitters. But normally you will be in the 6-18ft range so they just throw a number out there. That means if you measure your offset, and it is say 12 feet, if you film from 12 feet you set the offset to zero. It takes ten minutes to measure the offset in the camera, but most people don't bother.

    But let's say you are filming a rock concert and you are fifty feet away. Then your video will be out of sync by more than a frame, even with PluralEyes. But let's say for whatever reason you have a negative offset, like the in-cam processing of the AD converter works slower on the video than the audio. Then you could be a couple of frames out. And there is one more offset, which is codec offset. If you convert your video to Cineform or whatever, the audio usually gets moved around as well, sometime by quite a lot.

    I would say that most video that I see looks out of sync from time to time, including my own. Why is that? Because it is a royal pain to get it right on. It is a problem. It gets better if you shoot at 60p, but it isn't always possible in low light.

    In the case you mention, where the speaker is close to the mic, you will probably be behind the offset because the sound reaches the mic before the camera, and the light gets there first. At 8 -12 feet with the mic and the cam you will be probably right on, assuming a low latency from the recording equipment. With the clapper, you just trim the audio to the visual cue--not the audio cue--of the clapper, and you don't need to calculate the offset. This also eliminates the offset from any recording device you are using for the sound. Most people line up the sound with the sound of the clapper, as opposed to the motion, which is almost always going to be off by a bit.

    You will notice that the clapper will need to be used several times in a row to get an exact match. That's because the clap may come in the middle of a frame, or anywhere else. If you are fond of probabilities, you can calculate the number of claps to pretty much guarantee that one will line up at ten claps. Five will get you in the ballpark, and seven is usually good enough. Of course if you do that, ppl will think you don't know what you are doing, and you can estimate the arrival point by comparing frames.

  • @DrDave Very informative, thanks. I bought a clapper a few months ago but I am presently doing post on a short film I shot last year without one.

  • @DrDave You have opened my eyes to many new possibilities. Thank you. @Rambo I found camera mic windscreens on Amazon. They may be cheaper on ebay. I will check.

  • @Mckinise, also check your kids toy box for old fluffy toys. Sorry DrDave if this is considered misuse of equipment, I have posted it before though :-)

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  • @Rambo

    Yep. Put such thing on top of your camera, better use bigger bear. And add big sticky letters "Client that did not pay".

  • @Rambo I can only imagine.....no I can't.

  • @Rambo That will definitely be cheaper. What type of adhesive do you use, and how easy it it remove from the camera's finish?