Fan noise for interviews

[Giles Harvey]

So I'm off on my travels on a doc and need to mitigate the audio issue with the fan noise. What is the latest thinking here? Black shade at 41-45 degree's celsius? Adaptive seems to make no difference and quiet record lasts only a few minutes before sounding just as bad. All thoughts welcome

 

[Karim D. Ghantous]

All I know about this kind of thing is that if you have a few seconds of ambience, or possibly fan noise, and nothing else, you can use that to calibrate NR. I used to know what it was called in Audacity. But I did try it once, and it works. The caveat is that if you use this method, you will have to set the fan at a constant speed.

 

[Andrew Reese]

With proper placed lav and shotgun (omni direction pattern) you should not be able to pick up noise from the camera fan running on full unless using a wide angle lens for the interview and close distance of camera to subject.

First recommendation is don't pump too much gain into your mics that they pickup unwanted noise. Second recommendation is sound blankets / duvetyne. Third recommendation is get the camera further away from the subject (medium-telephoto lens). Fourth recommendation is get a better shotgun mic or focus more on a properly placed lav with low gain. If these recommendations are beneath your level of sound expertise I apologize but I wanted to get the easy fixes recommended first, just in case you are not doing those things.

I assume you are having this issue due to lack of air conditioning or outside shooting conditions (85 degrees plus) which makes the DSMC2 fans run aggressively? Indoors below 80 degrees the fans shouldn't run at all unless you are continuously recording for a long while. Try to not continuously record and take breaks between dialogue breaks to let the camera cool as it produces the most heat when it's recording.

If that all fails there should be a way to turn the fans off altogether I believe, but you would want to definitely black shade for the higher temperatures once the camera starts getting hot for best image quality and do the start/stop recording method I mentioned above.

Hope this helps. If all else fails use the adobe podcast tool as it literally will remove anything from background in recording. Literally anything (cars driving by, people talking in background, etc.I recently did an interview in a surgery room for a plastic surgeon and the equipment had terrible hum that we couldn't turn off. I took a chance and recorded the scene anyhow as it was the look the surgeon wanted. Adobe AI Podcast tool removed it all effectively as if it was perfectly recorded audio. I highly recommend you check it out at the link below. If you do use the tool, just an FYI but I toggle off the "speech enhancement toggle" so it only removes unwanted noise, as I found using proper EQ in post produced nicer audio enhancement than the AI tool.

Adobe AI Podcast

 

[Giles Harvey]

Thank you Andrew. I'll have a sound recordist but want shoot wide close up. The I/V will be in doors for around 3hrs. I have done a load of narrative with Monstro and it's a pain for sound. I just wondered if anything had changed but am very grateful for the suggestions. I know the post sound tools are now superb and this work will defo been given some love in post, however sound recordist ALWAYS complain about the fan. Thanks once again

 

[Leonardo Newman]

Do you have your fans set to adaptive preview - quiet record?

 

[Giles Harvey]

Do you have your fans set to adaptive preview - quiet record?

tried both

 

[Nick Gardner]

Really curious as to what your issues are. I have done hundreds of interviews with all flavors of reds since the beginning and never had sound issues. Unless you are right on top of the interview subject in a dead quiet room, I don't see how it's going to be a problem. If it is, maybe don't do that ? ;-) fall back a bit on a longer lens.

Nick

 

[Les Hillis]

The cooling system in the camera can only do so much. At some point it's the ambient temperature of the space you're in that makes the difference.

It's not just the sensor that's heating up, it's the media and other internal components, and it's not just the heatsink on the sensor keeping things cool, but the metal of the whole camera body dispersing the heat too.

If your ambient temperature is high enough, the cooling sytem in the camera has to constantly work at 100% just to artificially create a temperature differential on its own. That works to keep the camera running, but that's obviously also where the fan noise is maximized.

Having to run the fans at 100% can also create a loop where the hot air created and expelled by the camera just adds to the ambient temperature. In a worst case scenario, you just get a few seconds of 'Quiet Recording' before the fans automatically crank up to full or almost full speed.

I've experimented with it a bit myself and found there are minimal and marginal gains to be had from simply putting bigger additional fans on the camera. The sheer volume of air that flows through the camera leaves practically no time or space for cooling the air to any significant degree at the point of entry to the camera vent.

I don't recommend manually over-riding the fans. Apart from potential damage, the image will visibly degrade when the sensor overheats past the temp it's calibrated for.

You can store multiple blackshades in-camera anyway, so I would suggest black-shading at the highest sensor temperature available. All the temps you can black shade at will give you a useable picture, even if there are minor quality differences at the extremes. The DSMC2 blackshades cover quite a big range of temps too, so you don't need to have a lot of them.

Can't really add more than what others have already said in the way of solutions.

As far as I know the only developments in regards to RED and camera-fan noise have to do with the updated cooling system in the DSMC3 camera's.