Hello all!

a friend is giving me a 250w Compound Sodium Setup ( for free!! w00t! ) and i am wondering what bulb i would need to use to get the optimal results for it, i keep hearing that the ideal color temps are around 4000-6000º, but looking into it, the GE compound Sodium bulbs are rated at 2100º.
( as seen here http://genet.gelighting.com/LightProducts/...ODUCTCODE=26430 )

i am just a little confused on the color temp aspect of this build, i am not sure if i can get this working with that Light, anyone else know? or have some links where i can read into this?

thanks!

Sorry, you can't use that lamp at all, it produces only an orangish color.
You sometimes see those used in streetlamps.

Humm,

i just got the kit, and here is the Bulb:
http://www.bulbs.com/products/product_deta...inventory=13317

this one is saying that its rated at 4000º Color temp would that still give a yellow/orage tinge?
Here is the offical Philips link:
http://www.prismaecat.lighting.philips.com...l&loc=us_en

400k w/ CRI of 85 should be pretty good. maybe a tiny bit orange/red but nowhere as bad as the 1st bulb

Sweet!

are we talking about an amount that will be readily noticeable?

i did a little more looking around, and the wiki gave me the info that i needed!

http://en.wikipedia.org/wiki/Color_temperature

that explained it all for me, thanks again guys for the help!
i really cant wait to get this project started

That lamp is a MH ceramic retrofit it is a vary good PJ light with a small arc. Please post a good picture when you get it for us to see.

Can't beat free.

The 4000k color temp will be fine you might want bump the red down just a touch at the LCD.

The lamp model give away what they are

CDM****

Ceramic discharge metal

i keep telling my self that, but i am thinking about the end product and the simple fact that i dont want this thing to suck

i will snap a picture of it tonight when i get home, and i will have it up and running sometime this weekend.
i hope that its white, last time that i have seen it in action is was white. ( not THIS one, but the same model mounted in a lamp )

there is a picture, i am going to go light it in in a few.

hahah, i lit it.. i wired it up to a plug and plugged her in..

all i can say is WOW this thing is Bright! i cant take a picture without the cam Dulling it out making it look like its pitch black.. but that is far from the truth, this thing is lighting my whole basement.


one thing that i dont get though is that the light is... for ther lack of a better term, White.. this just makes me wonder how White the 65K lights are...

check it out,
[img=http://img300.imageshack.us/img300/5140/p1010001lq9.th.jpg]

another thing that i was Quite suprised was the Strike time ( allmost instant ) and the warm up time ( ~10 seconds ) i am impressed with it, but i am still not sure if i am going to use it...

You are one of the first to use the 250 watt ceramic. It is a nice lamp and may be brighter in a PJ than some 400 watt setup's. They list the CRI as 85 rather than 90 like some other ceramic lamps but it should still work great.

You migh want to show your whole setup.

Can you tell us about how wide and long the arc is?

I would put in in the PJ and see how you like it. You can always buy a 1,200 watt lamp later if you want

i cant snap a pic of the setup at the moment, but the Arc is 1 1/2 inchis tall, and 1/2in wide Roughly.

here is a pic of the setup, i have it roughly wired on the ground just to make sure its working and etc.



i have closeup's of the singluar components if you want them as well.

Newbie question. I think I understand that the point of a small light source is so that the 1st fresnel lens can re-direct the small light source origin into parallel light going through the 15" LCD. What is one had a large light source, say 600 - 1000W at 6500K, about 3-4” in diameter and 8-9” long? Then add a large reflector behind it and maybe, if needed, something to polarize the light instead of a 1st fresnel lens. The 2nd fresnel would still be used lens on the far side of the 15” LCD to direct the light to the lens.

Any chance this would produce a satisfactory result???

people have experimented with variations of that. LED array setups generally do not use a collimating fresnel because they can produce a good amount of parallel light through the LCD. Also, large parabolic reflectors have been tried but they have problems too.. don't think anyone has been satisfied with the latter.

Actually what I saw was a florescent type light that claims to be 6500k so I though that put in the neighborhood of being the correct color. The biggest one is supposed to be a 1000W equivalent in light output. There were a couple smaller wattages versions also. The price is right too! !

I don't think florescent bulbs will be as bright as comparable wattage meetal halide bulbs. neither will halogen. The reason we use MH is the arcs are relatively small and they are super bright. LL 65k T15 400w bulb is ridiculously bright.. you can't look at it with anything less than a welding mask.

Alright, so I wrote up a pretty nice post before about color correction filtering, and i'm fairly sure I was so tired at the time that i forgot to actually click add reply.


Anyways, it's possible to change color temperature easily using different filters. So it would theoretically be possible to get a different color temperature light...and fliter it to around 6000k?

I know the calculations to change different temperatures into the correct temperature, is this a good idea to try to use a cyan filter (to filter out red light). If so i'll try some testing to find a filter to correct temperature without killing the amount of lumens passing through.

Or... you could use the RGB controls on the LCD. Different means... same ends..