Yes, I have run shows where I have preheat programmed in the console to carry through the whole show. It seems like most lamp failures occur at cold inrush. I do lamp check before opening the house and keep them warm until the show ends. I only have anecdotal evidence, but I have not had any mid show lamp failures since I started doing this.
Warming up Source Fours and Fresnels
- Thread starterJLNorthGA
- Start date
Yes, I have run shows where I have preheat programmed in the console to carry through the whole show. It seems like most lamp failures occur at cold inrush. I do lamp check before opening the house and keep them warm until the show ends. I only have anecdotal evidence, but I have not had any mid show lamp failures since I started doing this.
JD
Well-Known Member
Two thoughts on the long running debate on pre-heat:
1) May have some benefit if the building is unheated and/or part of an open air stage and it's cold. Running the lamps will chase moisture out of the fixtures and help reduce noise.
2) I usually set dimmer trim before the show to a level just below or at the barely visible glow of the filament. Of course, most of what I ever did was rock shows where you tend to punch right to 100%, and the thought was to reduce inrush.
When the system is not in use there is no purpose to having any idle, outside of open-air venues where you are trying to keep things dry. I am not sure there is any advantage to even having a show idle if the first scene is a fade-up as compared to a punch-up, unless that scene is dependent on low end control (fairly dark.)
1) May have some benefit if the building is unheated and/or part of an open air stage and it's cold. Running the lamps will chase moisture out of the fixtures and help reduce noise.
2) I usually set dimmer trim before the show to a level just below or at the barely visible glow of the filament. Of course, most of what I ever did was rock shows where you tend to punch right to 100%, and the thought was to reduce inrush.
When the system is not in use there is no purpose to having any idle, outside of open-air venues where you are trying to keep things dry. I am not sure there is any advantage to even having a show idle if the first scene is a fade-up as compared to a punch-up, unless that scene is dependent on low end control (fairly dark.)
DELO72
Well-Known Member
There are a few benefits to running a Warm-up cue:
[Let me start by saying that I am defining a Warm-up cue as prior to the channel check before the show, you turn the system on, and slowly (over the course of a minute or so, bring all your conventional lamps to full for 30 seconds to a minute, and them let them fade out.]
1) You allow the halogen cycle to operate. Let's say you have a show where all your halogen lamps in your side light are never used at more than 30% intensity. (This is likely true of a few specials as well.) If the lamp is not allowed to get hot enough, the halogen cycle doesn't work. By having a warm up cue prior to each performance, you are allowing the lamp (which would otherwise not have had the chance to do so during the run of the show) to clean itself and have a working halogen cycle, thereby removing the tungsten particles off of the quartz and back onto the filament before the show. You're increasing the life of the lamp by doing so.
2) you are reducing the chance of a lamp "popping" when brought to full during the channel check. Nothing likes to be shocked without stretching. Not your hamstring muscle, and not filaments. By warming them up, you reduce the chance of failure due to stress during a fast bump to full later on.
I'm not an advocate of leaving them on pre-heated during the show unless there is a specific reason for it (for instance if you want a quicker response as one poster said earlier.)
But taking a minute prior to the performance to warm them up to full over the course of a minute can be helpful.
DELO72
Well-Known Member
My theory is that USHIO lamps are bluer because they are sad that more people use OSRAM. *Rimshot* (Taps the microphone) "Thank you, I'll be here all week. I just flew out from Cleveland and boy are my arms tired!"
Definitely check the voltage and weather it's a long life lamp. You find absolutely see differences between 115V lamps and 120V lamps, and regular hour (300) and long life lamps. Apples to apples they SHOULD be the same with minor variations production to production of less than 100K CCT for halogen lamps.
Dionysus
Well-Known Member
EXACTLY, part of this I touched on before... But the thing I really am bothered by is people doing their pre show "warm up" in the following ways (that I have seen):
- Putting all fixtures to 20% for a half hour before Preset (House)
- Snapping all fixtures to full, and leaving them on for 20 minutes.
Doing a slow fade up to 100%, then fading out is all good! Especially if as you mentioned the fixtures may not be getting up very high in a show, and you would like to make use of the halogen cycle to extend lamp life. Snapping "cold" lamps to full is never good in my eyes.
And as I said before sometimes putting a light on ever so slightly in a cue before a quick fade up is quite beneficial.
Ford
Sr Product Manager, Chauvet Professional
my whopping 2 cents... I used a preheat cue for my dimmer check. I wrote a macro that preheated all lamps to 15%, held for a few seconds, dropped them to 10%, and then grabbed channel 1 and set it to "flash-on". then I could step through the channels using the [+] and [-] buttons on my RFU (ETC Expression family of consoles).
Dimmer check was done after each show (supposedly... depending on my board-op, and excluding opening night as there was a mad rush to the cast party and/or bar), and at least an hour prior to doors prior to each show, from Dress rehearsals until closing night.
The pre-heat Macro kept the units from bumping from 0-100% during the dimmer checks, and did significantly impact lamp life.
That said, the only time I ever preheated during a show was to about 2% or 3% (depending on the tolerance for extra light on stage), and only when the next cue was a bump from 0. For instance, when trying to use incandescent fixtures for a lightning effect.
Dimmer check was done after each show (supposedly... depending on my board-op, and excluding opening night as there was a mad rush to the cast party and/or bar), and at least an hour prior to doors prior to each show, from Dress rehearsals until closing night.
The pre-heat Macro kept the units from bumping from 0-100% during the dimmer checks, and did significantly impact lamp life.
That said, the only time I ever preheated during a show was to about 2% or 3% (depending on the tolerance for extra light on stage), and only when the next cue was a bump from 0. For instance, when trying to use incandescent fixtures for a lightning effect.
de27192
Active Member
If you've stored your conventionals away over winter and are getting them back out for the first time in a while, sitting them at full for 15 minutes might not do them any harm just for burning the dust off, save doing it in the show and panicking any audience sat around the balcony rail or near audience boxes!
dthomas32308
Member
The main venue I work in now is pretty small so I do pre-warm lights but I do it as part of my lamp check too. Cue stack to fade them up over 60 sec to 100% which is enough time to get to the stage, do my check and use remote to go to the next cue to fade them back out as I'm returning to the booth.
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