I don't see how wire-polars could be applicable, as they need the light-box to reflect the mis-polarized light back towards the panel. Perhaps with LEDS clustered on a mirror surface this could have some applicability, however with our standard MH lamp setup, I don't see what good it would do us.

That's a very interesting question. I have a 175w ballast that I would like to use. Would I be better off getting a 250w or a 150w bulb for it?

Would both even work?

I have an ignitor that says it will work for 250&400w bulbs, but I know for a fact that it will work with a standard 150w MH. I also have a 10uF cap sitting here. Which bulb would I be best buying?

The ballast just says it works with MH, and that it needs an ignitor, will this work fine with these ceramic bulbs?. I can also possibly get my hands on a 250w Ballast with a built in ignitor. Would I be best doing that?

Since we're discussing arc's, I'm thinking this is one of those "rubber meets the road" thingies where 'theory' does not hold...but I'd like to hear some results... A sputter-effect, even if color-shift were to be present, would likely offset any gain.
The slightly higher-K/shorter-arc 150w-ceramic, paired with a 175w ballast, is a better-bet -- no? [At least until Q3/2011 -- when the 250w-ceramics at last reach-market...!]

heheh, so I might as well go a 150w, then by the time it dies, the right 250w may just have come out.

I called the USA OSRAM office because they list a HCT-TM 400W/942-NDL-PB
This is a 400 watt single ended power ball arc tube 100V 4.45A lamp.

They also list a HCT-TM 250W/942-NDL which is the 250 watt lamp.

The catalog is here.

http://www.osram.com/pdf/service_corner/10...B_PI_HCI-TM.pdf

The sales man said the 400 watt will not be out until the end of 07 but the 250 is sampling now and should be in the retail chain fairly soon.
He also sent me a speck sheet of the 250 watt but it was the 3000K lamp.

So I still don't know if any one has a 250 watt 4200K HCT lamp.

I think the 250 watt HCT in a parabolic reflector might be a nice lamp.

sorry, of topic...

AV

Do you know any sources for parabolic reflectors that would suit small panels
(7-10")?

I assume it means that the diameter of reflector should be at least the same as the diagonal measurement of the panel?

noob here... just wondering if this ballast: http://cgi.ebay.com/ARO-Electronic-Metal-H...VQQcmdZViewItem
will work with the 150 ceramic bulbs? Also, is there a good source of the 150w ceramic bulbs in Canada? Thanks

It won't work well with ceramic arc bulbs. You'd need "magnetic ballast" to get better results.

So you have tried this ballast and it would not power the lamp to full brightness?

Each ballast will behave a little different so you will have to try it out to see how it does. I see no real reason it should not work fine. It is a little pricy for a 150 watt ballast.

fyi, I have been using both an electronic ballast and a magnetic ballast to run the phillips ceramic 150 and haven't noticed any differnce except the magnetic(venture) takes longer to warm up

Could you specify ballast?
Does it output 1.8-or-better (as opposed to EBallasts deemed 'insufficient')?

heres the link, I got it off someone on ebay real cheap:
http://pewa.panasonic.com/lcd/products/mh_pdf/150w.pdf

nope, looks to be 1.4 amps

Yeah, I don't mind spending a little more on the electronic ballast because it runs cool and quiet and doesn't take as long to warm up. So mikyd1954, you think that ballast will work fine? Thanks everyone for the input.

"Silver Surfer" has tried it, so my comments were based on his experiment.

He used both electronic & magnetic ballasts to run a Powerball (which has "ceramic" arc) and compared these two... Results: magnetic ballast was the winner (for color temp and luminance - not for starting). If you want to get more "detailed" information, send him a PM or check his older posts . Mr. Elken has same experience too, and he recommends magnetic ballasts to run ceramic arc based bulbs.


Btw, have you experimented electronic & magnetic ballasts on ceramic arc based bulbs, or you're just ratiocinating ?

I have the CDM 150 and have run it on Coral Vue's 150/175 e-ballast and on an Advantage 250W mag ballast. Both work and seem just as bright. Don't have any equipment to prove if one causes the bulb to behave differently. When ChuckL gets back in town I may ask to use his luxmeter to tell.

I'm running the e-ballast because it doesn't make as much noise. They're both in an adjacent closet, but the mag ballast will require some sound dampening.

Your experience based on ballasts with "different wattages". However, Silver Surfer's experiment (with Powerball) was based on 150W ballasts (both were 150W).

Where are you guys getting the 150w ceramic bulbs from? I can't find anywhere in Canada or that even ships here? Thanks

The lamp requires 1.8A, the input current is the current required by the ballast.
Assuming 100% efficiency, the output is close to 1.8A.

1.4Ax120V= 168W 168W/96V=1.75A

did you mean a 150w mag ballast? I can't imagine if it ran on a 250watter you ouldn't notice any difference

Only one left, but I just bought 2 from a seller in the UK for 10 pounds/$20 US a piece. He agreed to ship to the States for $4 or so, so I imagine he'd ship to Canada as well. Only hitch is payment method. Still waiting to hear how he wants to handle that.

As noted, it's a 150/175 W e-ballast from Coral Vue (same ones making the 400W e-ballast for LL). Both very bright and I can't see the difference. The difference may be there, but I can't measure it.

Nice, sensibull... picked up the other one. Holy balls that was cheap. Thanks

wow just finished 99 pages and now my head hurts =D . i would like to say thank you to everyone that has spent their time and money into the R.D. in this thread.

i have seen a lot of people on this side of the pond looking for the powerball. i was wondering if any of the E.U. or Aussie members would be at all willing to start some kind of group buy? where 1 order could be shipped to a member here in the states and that member ships them off to the other members. or if thats to risky if the member that could get them would take seperate orders?


now back to the thread at hand. does anyone know the focal size of the LL fresnels? ive been toying with one i have lying around and i couldnt get a point smaller than 3/8 inch (about 10mm i think), maybe im just not trying hard enough. so my question is do you still get better results with an arc size going lower than the 10mm?

also do you still see the same increase in results from the pro lenses now that we can use lamps with small arcs? i thought the great part of the larger diameter lens was that it would catch the lost light around the triplet.

is there any reason for the heatshield now that we can use the 150w bulbs? and what was the estimated % of light lost by using the heatshield.

and lastly what was the final verdict on rear fresnels? 220, 330, 0.05 pitch, 0.02 pitch ?

thanks

Cool. Any idea how to pay the dude? He hasn't returned emails since my purchase and I have to assume he doesn't want me to mail British currency.

How do I get one of these in Canada. Toronto...

I'v looked all over the city, but everyone I'v asked thinks Im nuts. I tried to get one sent from the states, but unless its a box of 12 I'm not getting s&!t.

Please Help.

Look in the phone book under lighting and light bulbs, I found 2 retailers in Ottawa who had the Ushio Ceram 150W Rx7... I bought mine for around $60, a tad expensive but there is no shipping and there is a warranty that the bulb will not be broken! You can also look and call the hydroponic storesm they carry lighting equpiment, and they sometimes have the ceramic bulbs. I wanted the OSRAM SYLVANIA Powerball and found out that they are the ones that are very difficult to obtain at a reasonable price around here. Also, if you're looking for the G12, I found that they are sometimes available one ebay... and there is that store, I haven't try ordering from them, but it looked like they ship to Canada www.bulbamerica.com

Good luck

Paul Wolf Electric in Toronto has them, although they're f'n expensive, and you have to wait about a week while they special order them. Have a look at this post for more info.

Can I be the first post on page 100!

Nope..

Page 100?

The thread that keeps growin and growing and growing......

good thing I already ready through most of it before or starting over would be a PITA


arizonavideo: beat ya <nelson laugh>HA, HA!</nelson laugh>

ummm did i miss something ??

elken did you end up with a favorite rear fresnel(220/330) and what grove pitch did you find to have the least amount of cons?

since these lamps are so much cooler would you be able to use a short f l fresnel instead of a condensor lens?

actually I tried this briefly.... the problem is, that they put out less total heat, but right near the lamp, its still 300 degrees © (or more)...but...I think with a fan blowing directly on the fresnel and findin one that doesn't have to be right next to the bulb(maybe an inch away?), yeah...its possible...

anyone know what to make of these, i couldnt find the pdf for the info given

http://cgi.ebay.com/Philips-CDM-Mastercolo...VQQcmdZViewItem

and he has them listed at 2 bucks???

That may-well answer that question...but I'll rephrase for mine:
The rear-fresnel in PJ's incorporating a pre-con often tend towards a longer-FL frez as consequence (for better 'coverage'). Would just using a shorter-FL fresnel at rear [165mm-200mm] enabled by lesser lamp-heat of a CDM produce equal-benefit -- as per the use of a pre-con with 220-330mm frez in higher-wattage PJ's (assuming appropriate reflector)?

Well I may have mised starting page 100 but I have only two post to go to get to 2000 post!

Did any one find a 165mm fresnel for the smaller 10.6 LCD? It should work fine with the 150 lamp with maybe a Lexan heat sheild.

Gee...and I thought _I_ was 'wordy'...<g>
Maybe 2-165mm glued-up from AnchorOp, and rumor of one elsewhere for 10.6"-sizing, and Carpow has 200mm (and sometimes 180mm)...which are decent/cheap. A 200 mm is 'in-coming', so I'll review later.

well..no idea ...but I have been playing witl dazzlas precon calculator with the smaller size screens(I'm just waiting for that 10.6" to get hdcp and its hard finding a good precon for the shorter FL fresnels ... but(after rereading your questrions....are you asking if using a shorter fl fresnel will get you more light? if so, then yes... even a 100mm fresnel(assuming you could find one) would still be 4" from the bulb and would not get too hot......of course at some point vignetting would be pretty bad....you might try stacking your fresnels to get a shorter FL... not sure of the exact formula though

Can you clarify what you mean a bit? I keep seeing this general language "a good precon for the smaller panels", "a precon that matches your fresnels" and I can't really figure out exactly what people mean. Why wouldn't the 6.5"FL/4.5" diameter SS precon work? The numbers crunch out ok and I tried it yesterday with a 9" panel and 220mm rear fresnel and it worked fine.



combined focal equation is f/c = 1/f1 + 1/f2

HDCP will at some point be 'moot', I hope (either by 'work-around', or by a controller coming out with function-enabled/licensed). My primary-interest for a couple-years is just upconverting (by 880DX and/or HT-PC) my library of std.-dvd's.
Vignetting is a big-factor in 'balance', but I wondered as to simple 'brightness' between choice of longer-than-220 frez with-PC, and shorter-than-220-frez without-PC (prolly about the same). With the smaller 10.6"-ws there is a lot left to 'establish' re: lamping/optics/etc. for 'optimal' -- particularly with short-arc ceramics.

Most of the projectors here at LL are based on larger LCDs, 15 and 17”, so it’s generally considered that a pre-con and a 220mm rear fresnel is pushy it. But for smaller LCDs the 220mm rear fresnel and pre-con would probably work much better.

well, basically I mean that with a smaller panel, you can use shorter fl fresnel than with a larger lcd because the vignetting will be better in a smaller panel, and for example, if you use a 180mm rear fresnel with a 10.6...its hard figuring out which is the "optimal" precon, not that the 220/shed precon won't work...just that it might not give you the best balance between vignetting and brightness...but dazz is the precon man , see his answer above....

just found these on ebay http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...p;rd=1&rd=1

i cant seem to find anything that shows its spectrum but their website (osram) did say this

"The lamps have a high color rendering index (80-90 CRI depending on the wattage) and contain a noteworthy rendering at the red end of the spectrum, thus allowing for objects to appear closer to their natural colors."

anyone have any expericnce with these?

That looks like the Topspot (which some Euro-DIYers consider superior to Powerballs). These are a hair-pricey compared German-market...but at least are 'here', so no group-buy required.
If a Topspot, they strip them, for better indexing/lumens(?) but lessened-life, and would eliminate concerns re: 'wire-blob' (stripped pictured here...on left):

Click to view attachment

I've been told that the Philips bulb is the one to use.

I found the Philips CDM T-6 150W 942 G12 and the CDM T-6 150W 830 G12 at this site for $39.95.
http://cmhlampsupply.com/philips-mastercolor-lamps/ They are listed 4th and 5th up from the bottom of the page.

So far I'm still saving to buy a ballast, bulb holder and bulb.

But, which bulb is the one to go with Master Elken? The Osram, or the Philips?

do we get a noticeable increase of light when removing the glass case of the bulb? as well as the heat shield?

i ordered some small reflecters (35mm-40mm) from surplushed and with the glass removed from the bulb i should be able to get really nice results with them.

Don't know for sure, but I doubt it. The main reason for removing the glass is to get the wire out of the way.

Having said all that, the outer glass in these halide lamps is the UV protection and there's no way I'd be doing that unless the bulb is then completely enclosed in a luminaire with a hot mirror on the front. And I don't just mean enclosed in the PJ, I mean in a separate enclosure inside the PJ

no way Oz'man, you could get a tan while you watch your movies. win win =P




small print: just kidding, dont use your pj bulbs for tanning =D