MrJustin Posted June 15, 2010 Share Posted June 15, 2010 HI there everyone... infrequent lurker, first time poster here... I have a project coming up which has developed to the point where I have quite specific lighting requirements, and finding the lamp im after is proving harder than I'd hoped. I have 36 lamps poking out of a large metallic structure, and we will be running off a 5kw generator which will already be powering a prehistoric barco projector drawing max 2000w and a few other lights. \\ so here are my requirements, in order of importance. 1. Must be dimmable with the NJD DPX12/4 12 channel dimmer pack. (no fluorescent)2. 240v (cant be messing around with 36 transformers/dimming ballasts)3. As low wattage as possible. 80w is basically too much. 4. Narrow spot. 5. Ideally no more than £3.50 per lamp. I really wanted to fulfill all these with a par38, but Is this possible? or should I reconsider and go with Par16s? my concern is these will look a bit pathetic mounted into the structure im building. Any help you can offer is much appreciated., Thanks!! Link to comment Share on other sites More sharing options...
Brian Posted June 15, 2010 Share Posted June 15, 2010 Are you wanting to illuminate something or are the lamps there for visual effect? Link to comment Share on other sites More sharing options...
Wol Posted June 15, 2010 Share Posted June 15, 2010 How large is a large metallic structure? Link to comment Share on other sites More sharing options...
Ynot Posted June 15, 2010 Share Posted June 15, 2010 Yep - more info, and maybe a photo in particular, would be immensely helpful. Link to comment Share on other sites More sharing options...
MrJustin Posted June 15, 2010 Author Share Posted June 15, 2010 Ah yes, more info... OK the structure Is a 4m tall circular sculpture poking out of the ground like a 'c' rotated 90 degrees CW. (see my avatar for a rudimentary front elevation). Thnk 'stargate' with lights. Spaced more or less evenly around the above-ground surface are the lights, in 12 sets of 3. Each set has one pointing out of the front of the structure, one facing out of the rear, and on on the inside surface pinting towards the center point of the circle. the narrow spot is mainly for the inside lights pointing inwards, as I want them to make a kind of starred effect as they chase round the circle. The lights facing front and back need to be chunky, largely for aesthetic reasons. I'd like the holes in the structure accomodating these lights to be about 15cm diamteter, and covered with a metal grille, fopr which I will probably use reclaimed satellite dishes, the ones with lots of holes in them. My concern is that birdies begind these will hotspot in the middle ond look pretty puny behind the metal grille, whereas the par38 with the larger diameter will more comfortaby light the 15cm diametter grill more evenly and with more 'punch'. (only the most technical lighting terminology, here!) Photos not possible im afraid since it's still being built, and my scanner is on the blink so I cant post tech drawings, though I'll be trying to get that fixed later today./ Hopefully this explanation is clear. Link to comment Share on other sites More sharing options...
MrJustin Posted June 15, 2010 Author Share Posted June 15, 2010 http://www.meno.tv/share/gz_3d_01.jpg Link to comment Share on other sites More sharing options...
Brian Posted June 15, 2010 Share Posted June 15, 2010 I think given your constraints that your current thoughts are along the right lines. Maybe PAR38s for the lights in the faces of the piece and GU10s on the inside. Link to comment Share on other sites More sharing options...
Wingwalker Posted June 15, 2010 Share Posted June 15, 2010 Around the inside you could have the Par36 4515 pinspot lamp made by GE. They are rated at 6v / 30w with a very directional beam giving you the star effect you are after which of course you will only really see through smoke / haze. If you can find a way of fitting and powering them (safely) then thats your internal problem sorted - bearing in mind that they are normally housed in a purpose made unit with a 240v transformer. As for the outside, you could go with the cheap Showtech LED Pars (Par 56 size). Normally they come in black but can have a decent looking metal grill on the front. Power wise they are I think just 15w but again are normally supplied from 240v mains. I think that you could be hard pushed to get a lantern thats physically big enough for your design but will run on miniscule power. What's your budget? David. Link to comment Share on other sites More sharing options...
MrJustin Posted June 15, 2010 Author Share Posted June 15, 2010 Thanks for the input, guys. Brian: yep thats roughly what im thinking at the moment. Though ideally I'll go with two bulbs which are the same fitting (probably ES) so I have more flexibility and can interchage bulbs if necessary. Wingwalker: Those 15w '56s look great but are way out of my budget. Which at the moment stands at around max £300 for lamps, fittings and necessary cabling. the 6v jobs would be great but like you say the problems with powering them safely and dealing with all that makes it not as hassle-free as I'd like. YOu mentioned the GE lamps though, and I had a look around at similar products, and found these... par38 240v 60w 10degree spot / 30 degree flood ...though im wondering if I'd get away with something like this R80 reflector 40w spot (at £1.40 each they're almost half the price of the GE par 38's above) ...Any further thoughts ??? Link to comment Share on other sites More sharing options...
Tom Baldwin Posted June 15, 2010 Share Posted June 15, 2010 What's the reason for your pricing constraint on lamps? To keep maintenance costs down, or to keep the initial build cost down? If the former, you might want to experiment with fitting a halogen capsule lamp to a raylight reflector. I've not tried this myself, and there will be a certain amount of "engineering" to fit the new lampholder at the correct location to get a good focus, but I would expect this to give quite a tight, punchy beam which meets all of your requirements. You would need some sort of safety mesh to protect against capsules exploding, but you're talking about this anyway for aesthetic reasons. Actually, on that note, satellite dishes (even the perforated ones) aren't very transparent - you're going to sacrifice a lot of brightness going this way... Link to comment Share on other sites More sharing options...
MrJustin Posted June 16, 2010 Author Share Posted June 16, 2010 What's the reason for your pricing constraint on lamps? To keep maintenance costs down, or to keep the initial build cost down? Actually, on that note, satellite dishes (even the perforated ones) aren't very transparent - you're going to sacrifice a lot of brightness going this way... The latter, since at the moment 75% of the build cost is coming out of my (not very deep) pockets. It only has to survive a week in its first incarnation, with any luck after that I'll have a better budget to work with to improve on build quality, where I wont have to worry about keeping power usage to a minimum either. This is why currently im thinking to go with the cheap r80 reflectors for the front and rear lamps, and smaller, even cheaper reflectors for the inward facing ones, with a view to upgrade to something more sturdy next time around. I will have a play with the satellite dishes in the next couple of days... looking at them again you might be right, they may obstruct too much light... at the moment though, thats the least of my issues!! Link to comment Share on other sites More sharing options...
Brian Posted June 16, 2010 Share Posted June 16, 2010 ... found these... par38 240v 60w 10degree spot / 30 degree flood ...though im wondering if I'd get away with something like this R80 reflector 40w spot (at £1.40 each they're almost half the price of the GE par 38's above)CPC have PAR38's at £1.69 each inc VAT in their 'bulk' flyer. OOPS, just spotted they are 120W Link to comment Share on other sites More sharing options...
adam2 Posted June 16, 2010 Share Posted June 16, 2010 12 volt MR16s are very cheap, as are the transformers.You dont need a transformer for every lamp, several can work of one transformer, taking care not overload it. Reputable makes of MR16 can be purchesd for £1 each, and pound shops sometimes have packs of 2 or 3 for £1.A 105 watt transformer can work 3 lamps each of 35 watts, or 5 each of 20 watts and can be obtained for £5. Such lamps are widely used d0m3sticly, which could ease the expense if they can be re-used afterwards rather than being wasted. 40 MR16 lamps at £0.65 each = £2610 transformers at £5 each =£50 Well within budget Edit to add that not all halogen transformers are suitable for dimming, but many are, be certain to get the right ones ! Link to comment Share on other sites More sharing options...
MrJustin Posted September 27, 2010 Author Share Posted September 27, 2010 HI people, Just thought I'd post a couple of photos of the end result of this one... http://www.meno.tv/share/GZ_nowhere2010_101_WEB.jpghttp://www.meno.tv/share/GZ_nowhere2010_070_WEB.jpg Thanks for the advide, people. hopefully I'll be taking this out to a few fewsivals next year.... think I might need a structural engineer to sign it off first, though. Link to comment Share on other sites More sharing options...
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