"On air" lights

Marius Tatarasanu · September 12th, 2012, 12:36 PM

Help me understand one thing. I haven't found an appropriate category for my question. I work at a local TV station, and when I can, I try to understand all of it's techical parts and mechanics. Seeing that language, lack of knowledge from me and the technical state of the place I work, I can't get an answer to something that started bugging me recently.
In portrayals of TV studios, from what I understand that is happening, I always see that a light turns on over the camera that is currently "on air", so that either the presenter or guests know at which camera to look at.

I would like to ask what is such a sistem called, and if any of you are familiar with it?

Ervin Farkas · September 12th, 2012, 01:33 PM

Marius, salutari din Atlanta de la un Targu Muresean.

Those light are called tally lights and they work off of the video switch; the switch (mixer) sends a signal to the LED light on the camera when that camera is live. Google "tally light" for more. More complex systems come with tally lights, you can also add them later, provided the mixer has the appropriate driver.

tally lights | B&H Photo Video

I hope this helps,

Marius Tatarasanu · September 12th, 2012, 01:42 PM

Mulțumesc ! :)

Allan Black · September 13th, 2012, 01:36 AM

Hi Marius, just about all the prosumer and some consumer video cameras have on board 'record' tally lights as well,
some switchable on-off in the cams menu.

Many folk leave them turned them off, to avoid drawing attention to the camera outdoors or un-nerving the talent.

Cheers.

Chris Harding · September 13th, 2012, 02:32 AM

Most pro cameras actually have two tally lights ..one front and one back and you can have back, front, both or none enabled...As Allan says I usually run the back tally and leave the front off as I'm shooting solo with two cameras..it's reassuring to be able to see the back tally light bright red and know at least that you haven't forgotten to press record on the camera..while the absence of the front tally doesn't put your subject off!! In fact I was recording a wedding a while back and couldn't figure out why the bride's snow white dress had a red dot on it!!! My front tally was on, so now I just run the rear light so I know what state the camera is in!!

Chris

Paul R Johnson · September 13th, 2012, 03:32 AM

One of my student projects years ago was to design a tally light circuit for a mixer that didn't have it as standard. The basics were pretty simply - you took a +volt feed from something like the button light, and then used that to switch a semiconductor, through a resistor so it had no impact on the device - sort of 'sniffing' the voltage across the led/lamp. I remember the satisfaction at putting a few handfuls of bits together so it worked. Then I had the problem that the mixer had two rows of buttons, and the top one or the bottom one could be the live one, so the next design had to deal with which set was active and it suddenly got more complicated. They actually sell single units that can do this for radio stations (Canford Audio) so a light comes on outside the door when the fader on the mixer is open. Exactly the same system.

There are some commercial systems available that have little LEDs you tape under the lens and inside the viewfinder because tally lights are really, really important.

September 12th, 2012, 12:36 PM	#1
Marius Tatarasanu New Boot Join Date: May 2012 Location: Bacau, Romania Posts: 22	"On air" lights - a question Help me understand one thing. I haven't found an appropriate category for my question. I work at a local TV station, and when I can, I try to understand all of it's techical parts and mechanics. Seeing that language, lack of knowledge from me and the technical state of the place I work, I can't get an answer to something that started bugging me recently. In portrayals of TV studios, from what I understand that is happening, I always see that a light turns on over the camera that is currently "on air", so that either the presenter or guests know at which camera to look at. I would like to ask what is such a sistem called, and if any of you are familiar with it?

September 12th, 2012, 01:33 PM	#2
Ervin Farkas Inner Circle Join Date: Aug 2005 Location: Atlanta/USA Posts: 2,515	Re: "On air" lights - a question Marius, salutari din Atlanta de la un Targu Muresean. Those light are called tally lights and they work off of the video switch; the switch (mixer) sends a signal to the LED light on the camera when that camera is live. Google "tally light" for more. More complex systems come with tally lights, you can also add them later, provided the mixer has the appropriate driver. tally lights \| B&H Photo Video I hope this helps, __________________ Ervin Farkas www.AtlantaLegalVideo.com

September 12th, 2012, 01:42 PM	#3
Marius Tatarasanu New Boot Join Date: May 2012 Location: Bacau, Romania Posts: 22	Re: "On air" lights - a question Mulțumesc ! :)

September 13th, 2012, 01:36 AM	#4
Allan Black Inner Circle Join Date: Sep 2006 Location: Sydney. Posts: 2,951	Re: "On air" lights - a question Hi Marius, just about all the prosumer and some consumer video cameras have on board 'record' tally lights as well, some switchable on-off in the cams menu. Many folk leave them turned them off, to avoid drawing attention to the camera outdoors or un-nerving the talent. Cheers. __________________ Drink more tap water. On admission at Sydney hospitals more than 5% of day patients are de-hydrated.

September 13th, 2012, 02:32 AM	#5
Chris Harding Inner Circle Join Date: Jul 2009 Location: Perth, Western Australia Posts: 8,441	Re: "On air" lights - a question Most pro cameras actually have two tally lights ..one front and one back and you can have back, front, both or none enabled...As Allan says I usually run the back tally and leave the front off as I'm shooting solo with two cameras..it's reassuring to be able to see the back tally light bright red and know at least that you haven't forgotten to press record on the camera..while the absence of the front tally doesn't put your subject off!! In fact I was recording a wedding a while back and couldn't figure out why the bride's snow white dress had a red dot on it!!! My front tally was on, so now I just run the rear light so I know what state the camera is in!! Chris

September 13th, 2012, 03:32 AM	#6
Paul R Johnson Inner Circle Join Date: Nov 2005 Location: Lowestoft - UK Posts: 4,046	Re: "On air" lights - a question One of my student projects years ago was to design a tally light circuit for a mixer that didn't have it as standard. The basics were pretty simply - you took a +volt feed from something like the button light, and then used that to switch a semiconductor, through a resistor so it had no impact on the device - sort of 'sniffing' the voltage across the led/lamp. I remember the satisfaction at putting a few handfuls of bits together so it worked. Then I had the problem that the mixer had two rows of buttons, and the top one or the bottom one could be the live one, so the next design had to deal with which set was active and it suddenly got more complicated. They actually sell single units that can do this for radio stations (Canford Audio) so a light comes on outside the door when the fader on the mixer is open. Exactly the same system. There are some commercial systems available that have little LEDs you tape under the lens and inside the viewfinder because tally lights are really, really important.