(edit) This was my halogen thread, but I decided to make it a general incandescent/halogen light engine thread.

I saw a thread a while back with someone claiming he was getting a commercial projector quality image when he switched from a halide to a halogen lamp. Halogens give off more red light. Perhaps his lcd had a very narrow red light filter.

I was just fooling around with an incandesscent lamp in my projector and was suprised to find the image was not a thousand miles from what I get with the metal halide. I wonder what I'd get with a good slide projector bulb. Or a halogen lamp, or heck even an incandesscent that wasn't frosted...

Anyways, I wanted to try experimenting with different light sources, particularly halogen lamps, and I was thicking, perhaps I could try using a halogen car headlight. They have some nice built in reflectors and seem pretty dang bright.

but I know zero about halogen bulbs and how to run one. Do they need a ballast? What kind of base to they screw/plug into?

Most halogens run on 120v power.. so no ballasts.. and they come in a variety of bases.. usually not a screw type base though.

They give off alot more heat then a halide does.. and lamp life is alot shorter.

car lamps run on 12v..

What kind of base do you need? Are they sold or do they usually come with the lamp?

Do you think a car headlight would be brighter then an ohp projector lamp?

Hi Mikau,

I bought couple of the construction work light 500W few months ago for indoor photography.
The box is about 6"x3"x3" with reflector in it, tempered glass is out side. They were $19 a piece at harbor freight.

here is a cheaper one at lowes.

http://www.lowes.com/lowes/lkn?action=prod...54681-290-PQS45

The holder is ceramic little rectangle with a U shape gap in them. They are one on each end.

here is an image that I found on the web.

Click to view attachment

I have seen some small lamps with one holder instead of two(like above).

you may want to take a trip to the big hardware supply stores.

have fun

fw

Thanks man, yeah I've seen those at home depot but I didn't think of them till you brough it up. Thanks for the idea I just might give it a shot.

they release lots of heat thought. I mean, you could sweat from 6 feet away when they are on. so keep a large fan around or may be use one of those personal blower sold at walmart in fan section. normal 120mm fan will not be sufficient.

I have a feeling you work for walmart and i'd be more concerned with frying my lcd then keeping myself cool.

Actually I have a pretty powerfull ac fan already. But yeah I'd have to watch it closely.

Thanks again!

There is no way I will ever work for MalMart. but I have seen the fan there and was tempted to buy so I still remember it.

So what kind of fan did you say you have ? specs ?

I need a powerful fan for my light box that I am thinking of building.

Home depot, inductor.

go to www.homedepot.com and type in "inductor" in product search.

I'm using the 4 inch fan.

Mikau: Halogen lamps should be usable, but car headlights are probably not your best choice. The reflectors work well, but the lenses on the front are designed to produce a beam pattern that will not work all that well...

That being said, I was looking at a set of "offroad" lamps which have a 5" parabolic reflector, and thinking about a 5" PS1 screen... It might work nicely for something like that. The offroad lamps are spotlights, so they do not have the funky lens in front of the lamp. Might work well, and it already has it's own heat shield. Of course it's 12VDC, but I could manage something with that.

120V halogens should also work well, and you can get them in relatively small packages. Most of the ones for larger wattages are long though, and all the associated problems that causes... Short filament ones tend to be <100W, or have a VERY short lifespan, in the 100 hour range. (But if it costs $8/lamp, that might be okay.)

Thanks, Supra.



Where exactly? And where do you get a base?

Also most halogen lamps I've seen seem to be built into what they call a "PAR" (parabollic alluminized reflector) does the focal point of thise PAR have to be a certain length to match the rear fresnel? Or would I be looking for the ones that don't have a PAR?

Heres the slide projector lamp I'd like to try.

http://www.topbulb.com/find/Product_Descri...oductID_E_43697

the only problem is I don't know if I can get a base for it.

Also, that thing is 5.75 inches in length, I'm trying to estimate from the pic what the diameter is, to see if its small enough for a pro reflector. Theirs a smaller version with the same brightness and wattage but its got half the lifespan.

And...lest we forget. With a clear incandesscent and proreflector we can nearly double the lumen output, unlike with metal halides and their strangely opaque arcs. AND with this we'd be getting probably a little over 25,000 lumens, but with the small light source we'll probably get as much if not more light then a halide where half the light is spilled.

Anyways, I just found someone who sells P28S lamp bases, 70 bucks? Hmm.. I'll see if I can find another dealer.

OOooh another one.

http://www.sourceshop.com/product.asp?pid=156

This one has 17,000 lumens and a 500 hour life. Only costs 7 dollars more. ($27) But its 750 watts, being in incandesscent that might be the equivelent of a solar flare. :-/ also there's no pic so it might have both a huge filament and envelope.

(edit) apparently not! Heres a pic. That base has a diameter of about 28mm.

Oh yeah and it uses the same P28S base.

I say give it a shot. I was looking at bulbs like this too.

And you mentioned car headlights, well you could always try one of the halogen bulbs in a normal spherical reflector. Someone on the allinbox.com site made a projector using twin xenon bulbs from a car headlamp. And I know that the bulbs they use in movie theaters are xenon. And you can also get halogen auto lamps now that have increased output and color temp similar to xenon. All you would need is the base and something to convert from 120v to 12v.

Yeah car headlights might be good but I really think these incandesscents may be the way to go.

Oh yeah, and xenons seem to range from about 20 to 20,000 lwatts. They come in all varieties from household lighting to movie theatre projection lamps (as you said). So just because its xenon doesn't mean its bright. Brain said he considered xenon lamps early on but the good ones are super expensive.

Also, as far as cost of using an incandesscent light engine... the cost per hour would probably be at least half the cost of a commercial projector bulb, however you'd only be paying it a piece at a time. If I had a commercial projector and the lamp went I'd be out 350 bucks which would take some time to replace. But if it goes like every 2 or 3 months and I'm only out 27 bucks when it pops, I can reach into my pocket and replace it without breaking a sweat.

But I really think heat is going to be an issue with these. Even with powerfull cooling you can't elimnate radient heat. However, it may come in handy that I have a replaced rear polarizer. If I didn't the light would hit the polarizer, and warm up the lcd along with it. With a polarizer placed a half inch back, about 40% of the light will be cut before it reaches the lcd.

I'd try this in a minute if the base wasn't 70 lousy dollars. Still probably going to try it but want to hunt around for a better deal and if I don't find one, at least be fairly certain there is good reason to believe it will work. (lol.. thats a pretty mild stipulation)

Allright... the base listed for only $18.00 here: http://www.purelandsupply.com/item.html?UC...82&PRID=1133349

My only concern is it says halogen base. Still its supposed to use a P28S socket and thats a P28S socket. Hmm..

Well I searched for lamps with P28S sockets and got both halogen and incandescents.. I've also seem so halogen lamps that screw into standard household light sockets, so I bet it works for both.

Wow! I'm looking around and there are lots of lamps to choose from. I had no idea some of them were so bright. I think I should go with an incandescent, I think they have the highest CRI, but I read a halogen is a type of incandescent, but halogens seem to produce more bluish light, while incandescents are more red.

Dang... heres a lamp like the last one I posted a pic of only its 1,000 watts and 28,000 lumens, and half the lifespan (250 hours) http://www.sourceshop.com/product.asp?pid=158

now THAT's a solar flare!

Mik I built this PJ big enough to try all sorts of lamp combo's and mixes of lamps condensor lens, and 220mm to 330mm Condesor fresnels, i have not gone for smallest box etc... hehehhehe

this is gonna be a true prototyping box,, with full access, and quick 'close up' for full dark tests...

heres the box..

Nice! Are you going to be testing incandescents and halogens too?

And btw, which do you think I should try? Halogen or incandesscent? An incandesscent is likely to have a high CRI, right?

read PM,,,, not sure at this point,,, its a case of try everything thats affordable

All I care is to get high peak at the red green blue I want , whichever lamp provides that, is all that matters to me..

well few of these lamps tell you the cri, in fact, none of them do. Thats why i'm trying to figure out whats more likely to have a higher cri, halogen or incandescent. I'm betting its incandescent, they seem more redish then halogens.

Incandesent lamp are the bench mark for CRI. I cant remember where I see that, but I was serching it on google.

Sorry for delay...

For "small package" I meant short filament size.

The integrated reflectors are probably not goig to be appropriate, but might be worth a try, depending on LCD panel size more than FL.

@Johnzo: Actually sunlight is the benchmark for CRI, as a CRI of 100 is supposed to be high noon sunlight.

Incandescent lamps tend to have very little blue to them, so the light appears yellow. Halogens are more full-spectrum, there should still be plenty of red to them, but a little more blue as well.

I think the best balance in a filament lamp is likely to be the halogen.

Thanks, supra!

Arizona video is sending me a base and an incandesscent he's got lying around (unless he changed his mind) so I can test that and order a halogen lamp as well to see how it compares.

The best non MH lamps I've come across with high CRIs are the Solux MR16 halogen and Paralite full spectrum fluorescent.
I think they filter the snot out of the MR16s to get the CRI higher as their lumen output is low in comparison to a normal MR16.

Well I just googled them and all I could find was 35 and 50 watt bulbs. Do they come any higher then that?

Solux? No, not to my knowledge.

Well I can't seem to find the lumen output. Any idea?

What are you looking for exactly?
Reflectorized also?

Most normal household halogens I've seen have a CRI of about 99.

However, if you want to check the stats on a bulb, the best place i've found if you have some of the specs is www.donsbulbs.com

looks like a halogen with a mini-candelabra base might work well.

A 3200K halogen has a CRI of 100% I foun that a a web site.

Nice! I gotta get my hands on one...



No reflector, but some of these halogens and incandesscents have very high lumen output, however they're usually pretty high wattage so they're going to produce a truckload of heat which may be difficult to control. But we'll see what the high cri can do.

I tried a 60w halogen car headlight bulb, before I got my MH setup.

The picture was way too yellow and not bright enough to watch a movie.

yeah 60w is no where near enough.

I've been looking at halogens (I'm waaaay too poor for MH right now). One I found outputs 9500 lumens, has a good CRI from what I remember and costs $5.99 at

http://www.bulbs.com/products/product_deta...inventory=10029

A base for it is only a little more, it has a short(ish) arc...I figure I'll give it a try.

Try a sticking a 500 watt mini-can/e11 base halogen into a reflector from a retail projector or the lumenlab reflector.
This Bulb:
e11 bulb

This Base:
e11 socket

And the lumenlab reflector

The bulb runs off of 120v ac power, no ballast.

I have to warn you all I am a total newbie and have only just started thinking about putting a projector together. I have a 15" LCD stripped + Lumenlab lens and lamp kit basically just need a box.

I was mindlessly (for some reason I am usually mindless ) browsing the web and found a halogen rechargeable torch that claims to have 2,000,000 candlepower output. There are others that claim to be 1.5 million and 3.5 million candlepower also.

I thought I might try one of those although the lamp life may be crappy. I ordered one to have a play with since they were only $24.95 AUD. I'm thinking maybe remove the lens and just have the bare globe sitting in its reflector and see how that goes. May need to purchase some sunglasses!

With respect to the color output you can adjust the color settings on the LCD and if that isn't good enough a serious person could probably get a place to set up a proper color profile for the projector.

2 Million, 1.5 Million, 3.5 Million, 20 Million Candlepower

It seems there is some confusion as to how they measure this supposed light output. There is a black and decker 20 million candlepower that also states it is 3375 lumens or something like that. How the heck do they measure these things .. all this multi-million candlepower stuff seems a bit of manufacturing b....sh.t


What say you all?

Cheers, Goofy.

I have tried just about every shape and size of regular house bulb in my PJ. Not for long term use, but for testing alignment and screen fabrics and such. Also, just for fun. To experiment. I have found that the best so far is THIS BULB.

Here are two screen shots of it. That screen in these is tiny. But I have gotten a watchable screen 10 feet wide with it.

I think I'm going to save up the money for MH, but here's the best I found in incandescent when I was looking:

http://www.fullspectrumsolutions.com/neoli...ulbs_40_ctg.htm

Very bottom of the page.

Happy hunting...