UV comparison

[revbobuk]

Folks - I have a small stage in a Church Hall with a set of black drapes as a backdrop, and for a children's event I need to illuminate large (~75cm long) fish, which will be painted with UV reactive paint. Although the stage area is reasonably dark, the auditorium will have daylight illumination. So I'm looking for a UV lightsource, but there's no easy way of comparing the power of the ones I've seen available. There are 400W cannons, 150W cannons, 2 foot tubes, 4 foot tubes, funy little things that look like CFLs, and the prices vary a lot too. The stage is about 9m x 4m, and the hall itself about 25m long - there'll be around 100 kids in.

 

Can anyone give me some idea of how much power I'm likely to need, and what the relative efficiencies of the various UV sources might be? Any pitfalls I've not seen yet?

[Brian]

Where is the fish? Is it carried around? Or static? If static then what is it stood on/hung on?

 

The reason for asking is that the best way to get a good UV effect is to get the UV source up close to the object.

[revbobuk]

The fish will be static, on the drapes. And I was planning on lighting them from a bar which is about 1.5m away, maybe 2m at most, at the top of the drapes.

[Neil_m_123]

Folks - I have a small stage in a Church Hall with a set of black drapes as a backdrop, and for a children's event I need to illuminate large (~75cm long) fish, which will be painted with UV reactive paint. Although the stage area is reasonably dark, the auditorium will have daylight illumination. So I'm looking for a UV lightsource, but there's no easy way of comparing the power of the ones I've seen available. There are 400W cannons, 150W cannons, 2 foot tubes, 4 foot tubes, funy little things that look like CFLs, and the prices vary a lot too. The stage is about 9m x 4m, and the hall itself about 25m long - there'll be around 100 kids in.

 

Can anyone give me some idea of how much power I'm likely to need, and what the relative efficiencies of the various UV sources might be? Any pitfalls I've not seen yet?

 

I've used four 4ft u.v tubes on the front of a stage and it gave me quite good coverage to around the distance your looking at. I managed to run them off a 4 way as tubes only use minmal amount of wattage

[csg]

40w 4ft tubes would most likely be fine, particularly from 1.5 or so away, but if you want a narrower beam then a cannon would also be fine, all be it more expensive and heavier

 

for the benifit of the poster above, you could happily power 4 400w uv guns from a 13A 4 way adapter, even accounting for power factor, the total load would be approx 8A

[Sound In Gloucestershire]

personally id go with the 400w cannons, they are powerful enough to do the job properly. Just remember that they take a while to warm up and can sometimes cause interferance when triggering if on same circuit as sound. You also dont need to do aim that too well, just point them in the general direction. They cost just over £100 with a lamp, but are pretty cheap to hire too

[timmeh2]

Hi

 

At 1.5-2m range I think 2x 400W cannons at either end of the bar would suffice. As has been said before they have a very wide cone (>100 degrees) and can be noisy when they start up.

 

All the best

Timmeh

[rossmck]

Another vote for 400W cannons... I use two of them quite often to cover a small "church hall" stage of around 6m x 4m, given enough time to warm up they light both the UV painted backdrop and the cast costumes quite well, so they'd certainly light a backdrop if hung a little closer ;)

[revbobuk]

Thanks guys - useful information. Looks like 2 400W cannons will indeed be hired in. Can't see any reason to buy; it's just for a week. Will they work off a dimmer, or must I use a DMX switch? If switch it must be, then does it have to be relay, or will triac based switch do? And just how long do they take to warm up - are we talking 10 minutes before they are up to 75%, or 10 seconds?

[LXbydesign]

NOT dimmer!!

 

Just run up a bit of 13a hotpower - and if ur hiring, just check with the company if you may need a jumper. They might have their UV's fitted with 15 or 16amp plugs. Give them a couple of minutes to warm up nicely and off you go!!