4464 Bittern to do 90mph on ECML - 29 June & 27 July 2013

Doh!! Slipped up there. She hasn't run in that guise for a while.

 

"Slightly" off topic here. Mods, please feel free to move this to a new thread.

I'm heading up to film 4464 on Saturday morning just north of Arlesey, but my location is under the wires (at a foot crossing, I might add!). I was wondering if anyone has any tips for reducing the amount of interference on the audio clips when filming with an external microphone. When I filmed at Hanwell back in April, I discovered my external microphone picks up a lot of interference from the overhead wires - even with editing, the audio still has that annoying hum in the background... I'd prefer it if I didn't have that hum in future shots!

The video in question is below and should start at the right time. If not, then the Hanwell clip begins at 2:40:

http://www.youtube.com/watch?feature=player_detailpage&v=Bz_EnbmKNxo#t=161s

Thanks in advance!

James at SVN

 

Hey SteamVideos - depends on what type of external microphone you are using - directional or condenser style? - these things sound really simple but trust me - make sure the cable is short between the microphone and the camera - and if its a directional microphone, try and keep the microphone at right angles to the overhead lines - this should reduce noise.

The best way to record with the minimum amount of hum, would be be to record the video on a DSLR and then use a laptop, condenser mic (with wind shield) and pre-amp, and use the gain on the pre-amp to control the amount of hum picked up...However, near a foot crossing this probably wouldn't be practical at all!!!!

 

you probably need a mike with a 'D' suffix after the model type, may well not be the wires at all but the interference between camera and mike

 

Just to confuse matters. I've done sound at some locations with OHL and picked up hum but not others, all with the same set up. I filmed 70013 from the platform at Arlesey last week and no hum at all but that was with the camera's internal mic.

Edit : just viewed your clip. Never had that high pitched a hum, my hums have been lower frequency than that.

 

To be fair, it's not always the wires that can interfere with Video, when I did it years ago, quite often I'd get inteference at Small Heath despite the nearest OHL being around 2 miles away, prime suspect was a mobile phone mast a hundreds yards down the nearest road.

 

Flyingdales was a great source of electromagnetic energy and that used to play havoc with my mic. The cure for that was to set up the mic in the tailgate of my car and use the body as a sort of faraday cage. The border area if the DDR was another place to play havoc with mice. Everywhere was alive with interference from radars and the like.

 

The best answer to your problem is to use mikes with balanced leads stops all the interference.

Cheers Dave

 

Perhaps others have different experiences but the staff / management at London King's Cross (at least on three of my recent visits) appear to have a sensible attitude towards opening the ticket barriers, allowing those not travelling to enter the platforms to see and photograph departing steam engines. Hopefully this will also apply early tomorrow morning.

 

Well, my best advice is - don't record under the wires. You shouldn't have any problems 20 yards from the line.

Big Dave is right. The most effective way to cut out interference is to use balanced microphones and cables (usually, though not necessarily, those using 3-pin XLR plugs and sockets), and even then, it only cuts out interference picked up by the cabling, not by the mic itself nor the audio circuits in your camera or recorder. It works by splitting the signal between two wires, turning one signal upside-down at the mic end and turning it back the right way round at the recorder. Any spikes or hum picked up by the cable are cancelled out when the two signals are re-combined. However, that means borrowing, buying or hiring different kit.

Otherwise, all you can do is keep your cables as short as possible. I suppose you could try to construct some kind of Faraday cage around the camera, but that might make it too difficult to operate.

So, I go back to my first point - set up your mic and recorder away from the wires. But then you need to film from there too, or the sound and pictures won't match.

 

Are the 90mph sections still the same as those published in SR? Anyone know of a good location between peterboro and neward for a fast shot?
Steve

 

Steamage is right get back 50 yards or more from the track, your soundtrack will sound better, otherwise the sounds of the train wheels will overcome the sounds of the engine.

Mods would be nice to have a subsection under photography where help can be found for both sound and video recording.

Cheers Dave

 

Thanks to everyone for their advice/recommendations. I use a Rode Videomic Pro (directional) with a Panasonic TM900 and the microphone has always been sensitive to interference. Since I uploaded the link last night, I had a look at one clip that I haven't uploaded from Hanwell. It is of a class 166 passing on the up fast a few minutes after but it doesn't have any interference... It's very strange!

James at SVN

 

Wrap in tin foil, oh yeah, and get close to the wires!!!!!!!

 

I refer the honourable gentleman to the answer I gave a couple of pages ago!

 

Oops! I even remember reading that post!
Thanks!

 

Dave, there's 300 odd pages of photos under the section 'PHOTOGRAPHY' (would you believe) on the menu page . There's some good stuff there actually..., but not a lot of advice...Pete

 

Lots of video please gentleman (and ladies!?) - Hoping my leg will be fixed enough to see the last 90mph run in july...Anyone on here travel up from the south west?

 

You will notice that the hum and interference gets louder depending on how near a service train is to you, ie the nearer a pantograph drawing current gets to your spot on the catenary, the louder the hum gets. Have you tried wrapping the audio lead round a ferrite core?
Its all very well to spout "get 50 yards away from the wire", you shoot where you can get a view. That view is harder to get under wires.

 

Interesting - I'd not made that connection before.

Sure, open views of railways are ever-harder to find, especially if you have the misfortune to live in a vast urban area like London. Steam On The Met last month showed that very well. On the other hand, if you want good sound, and you don't have balanced audio gear, you have to get out from under the source of the problem. Good, clean sound makes such a difference to video, even after YouTube has compressed it within an inch of its life.