American DJ UV COB Cannon
This is a fantastic piece of kit! The problem with many of the LED UV fixtures around is that they just don't cut it, at least on their own. You often need 2 or more to have enough whelly in any sort of reasonably sized venue, which means more items of kit to lug in and setup, more cabling, etc. And as for the older non LED UV fixtures, well unless you're using the big classic bulb based UV cannons there's not much point to any of them unless you're DJ'ing in a bedroom!
This fixture doesn't have that problem at all – its fantastically bright and has a great beam angle. The 33º beam quoted in the specs doesn't seem quite right to me, as it seems to give off a wider angle than that, but I've not measured and it may be that the 33º is simply the most powerful part of the beam. This beam angle, whatever it actually is, is tight enough so you can direct it at a dance floor and not waste the effect like some other much wider beam angle LED UV fixtures do. I'd say its something nearer 45º which is about perfect unless you are in a really small venue.
There's a catch though – for mobile party DJ use where guests are relatively near the fixture its single COB LED emitter is just too bright. Yes its UV, but UV LED's still give off visible light and because all of that 100W of LED light is coming out of an area around 30mm x 30mm, when you look at it you get an image of the square LED emitter burnt into your vision. Its not painful, but you really notice it when you look at something else and you have a weird blob in your vision which takes time to fade. After a while it becomes really irritating to have the fixture in your field of view if you are within its beam. Even with the intensity dropped to 50% I found it was still a problem testing with a distance of 3m to the fixture. To be fair this isn't a failure of the fixture at all – it isn't sold as an audience facing light, but with all of that lovely UV power it would be so nice to be able to use it that way!
Fortunately there's a solution in the form of diffusion lighting gell. You'll probably be able to pick up PAR56 sized squares of it off ebay very cheaply and they turn this beast into an unbeatable mobile party DJ UV fixture.
Using "F1 quarter diffusion"
Its diffusion so unfortunately it does kill off some of the brightness of the beam, but it makes it usable in a straight on application so that's the toss-up you have to get over. Without the diffusion you'd be having to drop the brightness anyway to stop it blinding people so arguably you haven't really lost anything. This amount of diffusion gives enough of a spread of the hot spot within the fixture when you look at it to massively dumb down the hot spotting problem. You can still get it if you are near enough and deliberately look into it, but you can always drop the brightness in smaller venues if it's an issue. What it does though is remove the problem where the fixture will start to really irritate people after a while, as long as you have your lighting rig reasonably high so its not directly in peoples field of view.
One advantage is that as part of what the diffuser is doing you get the UV light bleeding off to the sides of the main beam – not with anything like the same intensity, but because this fixture is so bright you get enough for the UV fluorescing effect to happen for people who are out of the main beam but are reasonably close. As for the main beam, its made a bit wider by the diffusion and is still more than bright enough in small and medium sized venues even with other effect lighting on. With a room in blackout it is stunning.
Using "F2 half diffusion"
This gives you a very noticeable drop in brightness of the main beam but then no problem at all when looking at the fixture head on. Its also much better at spreading the UV light, but you've lost much of that that intense beam which can look so gorgeous when it hits UV reactive pigments at a distance.
Using quarter diffusion gave the best of both worlds for me – still a bright beam which can be lowered in intensity if the device is close to guests and fine at full intensity when the light is higher up on stand or stage. However if you do a lot of smaller gigs with the light close to the guests then maybe 1/2 diffusion would be better for you.
Fitting the diffusion
The reason the COB cannon is quite large is that inside there's a whopping great aluminum finned heatsink drawing the heat away from the LED matrix, and (quiet) fans to blow air through that heatsink. Its actually a really nicely engineered fixture The air exits at the front around the glass so you can't just tape the diffusion to the front as you'll impede the cooling. You can either get a PAR56 gell frame and come up with a way to fit it on but leave an air gap, or if you will stick with always using the same diffusion gell and are handy electrically (and don't mind voiding warranties) its actually really easy to fit the diffusion internally. Just remove the front plate, then undo the 4 screws holding the glass assembly and front reflector in and then take apart the glass holding assembly. Your diffusion can then be added to the inside face of the glass, everything re-assembled and you have the perfect audience facing UV cannon! Adding the diffusion internally shouldn't cause a heating issue as it doesn't block any air flow path and as the light is LED there's isn't heat causing infra red within the beam.
General Review Points
Dimming curve
Pretty nice but snaps on and off at bottom end (not enough bits of PWM resolution for a clean fade from off to on)
Fans
Very quiet and temperature controlled (only operates when required)
Sound to light
Doesn't appear to work at all on my unit. Not an issue for me as I'm using a sound activated lighting desk to DMX control it (switching between static on and pulsing this thing to the beat of the music looks fantastic with people on the dance floor and it varies the light show, particularly if you vary how it pulses (e.g. sharp flick on's, slow rhythmic fades, etc).
Menu system
Horrible, very un-intuitive and requires the manual to be got out for everything. No attempt to make easier by helpful silk screen printing on rear panel, even to identify which digit of the display is the mode. This is my one big criticism of ADJ kit generally – they don't have someone who gives enough thought to the user interface and stand alone modes. I run a product design business and have programmed many similar devices in my time and there are ways to make simple 7 segment display user interfaces much easier on the user, plus various things which should be there as stand alone and linked mode features which ADJ just doesn't bother with. They make great kit engineered for a great low price, but with just a day or two more programming time invested in the development they could be so much better with no impact on the build cost.
UV Power
Fantastic, really really good – brings a great big smile to your face when you first see it!
Build quality
Surprisingly good – its a relatively low cost fixture but the build quality appears nice and tough. Fixings aren't thread locked and shake proof washers aren't used everywhere, so not built for life on the road proper, but for the price its very well designed and built from what I can see.
Cost
Not the cheapest UV fixture around by any means, but its just under 100W of LED UV! There are 54 individual 1.8W UV LED's built into the COB emitter matrix! When you compare that to other UV LED fixtures its incredibly cheap and amazing value for money.
