Canon 7d Audio sync with zoom H4 over long video clips

This is a quick test of the canon 7d with the zoom H4 to find out how much drift you get when recording a long video file while using the zoom for out board audio. I turns out you looks about 7 frames every 10 min which is corrected with a 100.042% clip correction.

Category:

Science & Technology

Tags:

• canon
• 7d
• audio
• recording
• sync
• sound
• h4n
• interactive
• tutorial
• magic
• lantern
• zoom
• h4

[SquickyPantsy]

is there any connection with the frame rate?

[onelonedork]

@SquickyPantsy No it appears the the older Zoom h4 doesn't have a very good internal clock. Audio can drift as much as 20 frames over the course of a long clip. If it were a frame rate issue you loose about 6 frames per second. The drift would be much more dramatic.

[jallsbrook100]

How did you connect the zoom to the camera?

[onelonedork]

@jallsbrook100 In this video the zoom is recording audio and the camera is using its on board mic, there is no connection between the camera and the zoom h4.

[JWD96]

where can I find this mount you used to put the H4 on to the 7D?

[onelonedork]

@JWD96 Its a flash bracket i bought used on ebay.

[artpimpjulz]

 I use the Q3hd to shoot live band vids - My only solution is to use Final Cut to slow the footage to 99.9042% - and even then it is still a frame or 2 out after 10 mins - making audio mixing impossible.

the other cameras i use are fine, from a £100 canon ixus to a £3k Sony V1 - all stay in perfect sync

[franciscanfriars]

Set H4 to wav44.1khz/16bit and rec. at 24fps on 7D and it'll always be in sync.

God Bless.

[kirikset]

It is not a problem at all) I just use a standalone dualeyes sound sync program and all you have to do is select "correct for drift" and it automatically corrects audio drift. DualEyes also syncs audio with audio sample accuracy and not just with video frame accuracy. Also you dont need a slate any more)

[galtyyy]

@onelonedork

Do you know how long ago the improved internal clocks started coming out with the zoom H4s?

[skonatrix]

its out of sync because ur sample rate was diff on the ZOOM than on ur camera.