Backstage Blue working light

[sunray]

I've tried different colours over  the years and found blue is not a visible as other colours if it does happen to spill and as Ninja mentioned it is good for flou tapes.

 

But some consideration to the decor colours comes into it, I tend to use 10W RGB floods for this situation and a quick fiddle with the remote control soon finds the preferable colour and light level. One of the AmDram groups I work with is predominantly elderly and we end up with a light blue otherwise they have no depth of field to their vision.

 

The one comment that has come back time after time from musicians is Red makes the notes on sheet music jump about.

[WxmMike]

Hi,

Recently found these LED 2W BC blue lamps with excellent colour rendering, and prospect of long life - 20000 hour life with a 2 year warranty.

https://www.tlc-dire...s/LTGLSBCB.html

Replaced 15W tungsten wrapped in blue gel !

Mike

[adam2]

Many suppliers now offer blue LED lamps to replace coloured GLS lamps, The choice tends to increase at this time of year due to the demand for coloured festive lighting.

 

A one watt blue LED lamp, or two watts at the most, will replace blue coated GLS lamps, with longer lamp life and much reduced energy consumption. 10 blue lights each 25 watt incandescent will cost about 4 pence an hour to run. If replaced with 1 watt LED lamps to cost is a tiny fraction of a penny an hour, 0.16 pence an hour.

 

The energy used by blue backstage lights is not great, but every little helps. If the lights are used for 1000 hours a year, then the energy cost is about £40 a year for 10 blue incandescent lamps or about £1-60 a year for LEDs. Lamp costs will also be reduced.

 

 

 

[gyro_gearloose]

Earlier this year I made some back stage working lights out of some 5mm blue LEDs, some plastic conduit, and some round plastic conduit junction boxes. The lights consist of clusters of three LEDs in series running off a 12 volt power supply. They are about 20 feet up in the air, and the clusters are spaced about 4 feet apart. They light up our wing area nicely without being too bright. In fact the first cluster I made used 6 LEDs, but I found that to be too bright!

[sunray]

Earlier this year I made some back stage working lights out of some 5mm blue LEDs, some plastic conduit, and some round plastic conduit junction boxes. The lights consist of clusters of three LEDs in series running off a 12 volt power supply. They are about 20 feet up in the air, and the clusters are spaced about 4 feet apart. They light up our wing area nicely without being too bright. In fact the first cluster I made used 6 LEDs, but I found that to be too bright!

I have wondered about something similar, but haven't had the guts to try yet, however there was this set of 3 steps in a very dark corner and in a rush I soldered a 10mm blue LED to a couple of AA's and a resister to get us through dress rehearsal. It was far too bright so a higher resistance was added. It ran for nearly 2 weeks from Thursday to Tuesday which covered the final 2 rehearsals, 7 shows and wash up. By the next Thursday it had extinguished. I usually use 10W RGB LED floods dimmed right down so realistically they're not much different to a bright LED in terms of output

[adam2]

Mains power if reliably and conveniently available is preferable to battery power on cost grounds.

 

A KWH purchased from your energy company costs about 16 pence. A KWH from disposable alkaline cells costs from about £50 to about £200 !

 

Despite this, battery powered LEDs are worth considering when only moderate lighting levels are needed, and in particular for short term or temporary use. A good quality ultra bright LED gives a useful light when driven at 10ma, if powered from 3 alkaline D cells via a suitable resistor, then the run time is about 2,000 hours or nearly 3 months of continual operation, or several years of intermittent use.

 

And verging into d0m3stic territory, reducing the LED drive current to 1ma makes an excellent night light for a young child. Run time 2 years of 24/7 operation or about 4 years if used only at night.

 

 

 

[sunray]

<br />Mains power if reliably and conveniently  available is preferable to battery power on cost grounds.<br />A KWH purchased from your energy company costs about 16 pence. A KWH from disposable alkaline cells costs from about £50 to about £200 !<br />Despite this, battery powered LEDs are worth considering when only moderate lighting levels are needed, and in particular for short term or temporary use. A good quality ultra bright LED gives a useful light when driven at 10ma, if powered from 3 alkaline D cells via a suitable resistor, then the run time is about 2,000 hours or nearly 3 months of continual operation, or several years of intermittent use.<br />And verging into d0m3stic territory, reducing the LED drive current to 1ma makes an excellent night light for a young child. Run time 2 years of 24/7 operation or about 4 years if used only at night.

 

My botch was never intended to be the final arrangement, indeed I didn't actually expect it to be enough for the job and fully intended to bring in another light for the remainder of the event, but the truth is I forgot for the following night.

After that I did bring a light in but there always seemed to be something more important to do prior to the show.

The experience has certainly opened my eyes to further possibilities.

 

On another point, I regularly use 10W 12V LED flood lamps on a 7AH (possibly on a 3-4m tripod) for portable work lighting and even for an outdoor carol service.

 

In my mind I question your 2000h as it feels so counter intuitive, from my own discharge tests AA's are around 2AH (200h @10mA [which coincidently matches my experience]) and guess D's are say double this but I haven't looked up their capacity.

 

OK so now I've looked them up:AA's 2AH & D's 12AH

[adam2]

Alkaline D cells of reputable make and discharged slowly are more than 12 AH ! 18 to 20 AH more typically if discharged slowly. Faster discharge substantially reduces the capacity, Maglite flashlights quote about 12 to 14 hours service with a 750ma bulb or about 9 to 10 AH.

 

So with an LED current of 10ma, about 2000 hours or nearly three months. Purchased in bulk they cost under £1 each. £2 for 2000 hours of yellow light, or £3 for 2000 hours of white or blue light.

 

D cells are the largest capacity readily available disposable cell. 6 volt screw terminal lantern batteries are up to 54 AH, but are more expensive per watt hour than D cells. Very large disposable cells of up to 2,400 AH do exist but are costly and not widely sold.

 

 

 

[sunray]

I searched for 'alkaline cell capacity' and the first site I found with a table of capacities 12AH at a starting discharge current of 50mA and for AA's 2.1AH under the same conditions. I accepted this as my own tests of Duracell Vs Greencell came out at 2AH.  

 

I've rechecked Google since and the variety of different capacities from 8 to 24AH throws some of the results into doubt.

 

While looking I came across the 6V lantern battery as 12-26AH, one of the other arrangements I did was a pair of Varta 4R25X to run a car 12V 48W spotlight for a vehicle to move around a stage without wires, the scene lasted for under 20 minutes and the batteries didn't quite last for the 3 shows. so under 4AH at the very high discharge current of 4A or so, is somewhat below what I'd expect.

[adam2]

The 6 volt lantern batteries with two spring terminals on top are indeed of very varying capacity up to about 26AH for the best.

 

My figure of up to 54AH was in reference to the larger type of battery with two screw terminals on top, type 991 or similar. 100 hours service was claimed with the commonly used 4.75 volt 500ma sealed beam bulb, that was the total in intermittent use however, not 100 hours continually.

 

There used to be a still larger Ever Ready 6 volt dry battery of over 100 AH in the older zinc carbon technology, very big, very heavy, and barely portable, I have not seen one for years.

 

 

 

[alistermorton]

A lot of the Ever-Ready batteries are now discontinued, more's the pity. I found the PP4 was always a useful size.

[adam2]

A lot of the Ever-Ready batteries are now discontinued, more's the pity. I found the PP4 was always a useful size.

 

 

Yes, regrettably. Flag cells, 4.5 volt screw terminal battery, 3 volt type 800 cycle lamp battery, No 8 battery, are now all extinct from Ever Ready or other mainstream manufactures.