I have just cruised thru the elbeq umm thread looking at 1000w star wars pics,,,, they look good but hard to tell what the real contrast is..

the one thing that still puzzles me, is am I missing something,,, why is my image from 150 watt still impressing me,, being almost 90% less by lumies..

Welcome back elbeghast. BTW - did anyone independent ever get their hands on one of your magical high-transmittance LCD panels?

what panel??????

as far as I know,,, and this is from a guy who lives in shanhai, and deals with this kinda stuff said the best you can get from a single tricolour panel is about 11%,, even that would be good

ahhhhh new test,,,, strip a panel bare and measure it,,,, I bet you will fins the fair portion of it will be polar bearies


geez I am dummmm ,, umm have panels here,,, do it myself hehehehehhe

damm why not did i before it do,,,, dohhhh

The EXIF is interesting in those pics.

DJ

how so,,, detailssssss



ummm I dub this CDMism's for now,,, because it all fits,,,,,,,,, views please

the answer is right in front of us,,,, WE JUST need to see the real answers,, and I no have dig at anyone,,, for all I want is real info,, objective answers, so I can see where and what we really need to do,,,

Simulate a short arc lamp. Setup the PJ with your fave 250 or 400 lamp but align the lamp with one electrode centered to the fresnel/LCD.
Now place a metal aperture stop in front of the lamp so only light emitted from a small area around the electrode passes to the fresnel.
You'll lose something like 60-70% of the total lumens normally used but what you do get is from a very small area, like a short arc.

ahhh but with a longer arc,,, the lumens per MM are less,,

I call the balance as field illumination effect,,, suspect,,, loss of contrast detail

mmmm,, a term to describe the dark scenes, when using my setup,,, the dark scenes, and said before CSI in lab,,, sort of dimmed light situation,,, well it has LUSTRE,, even a piece of chrome metal in a dark corner has a 'real' look to it,,,, this is the subtle detail I now get,,

also if you have something that has 'lets say' several shades of pink,,, you can see the difference, along the object,,, before it was pink,,, but all one shade.... hmmmm how else can I describe....

sort of like greyscale,, I now have colour scale,,, hehehehehe

Trust me everyone, when I say this. I have built 5 or 6 projectors, plus a retro fit. 2 of which are high watt bulbs. Don't believe anything about a 1000w bulb unless you have a small arc like AV does. I had a 71mm and a 55mm, both smaller than someone elses. Remember, the arc length isn't the total, you have the white ends still that give off much of the light as well, so add on about 20mm to the actual arc length. You have to have a small arc for two reasons. The light does not fit into the lens, and the large arc gives a very blurry picture. I have a 1000w bulb and ballast just sitting as junk right now, because it doesn't work. Ever heard the words, "don't believe the hype?" Well don't. The smaller the arc the better, because the picture is sharper. If someone says you can get a long arc to show a sharp picture, they are full of it. Plain and simple. The reason, is the longer the arc, the more directions the light is hitting the middle of the fresnel. Thus it looks the same if you try to use two lights right next to eachother, kinda like double pictured. If you don't want to listen to me, feel free to waste your money. I did. I am posting this, because I don't want anyone else to waste their money. Now, that being said, yes, using the short arc 1000w+ lights are great. Just remember short arc "important" Peace...

nice point,,,, I cant say that, simply because i have not gone above 400 watt,, so no knowledge other than theory,,, but going bacwards has surprised me,,, simply because i was after the most lumens i could get,,, like everyone else,,, well now I am challenged,, mostly myself heheheh

ok,,,, from now on anyone who posts pic must declare,,, their EXIF data

or exposure times, and mods,,, I generally do

for example all my hand in fifth element have been 1 second,, others have varied,, even to just full auto,,,

but the EXIF on eglbeq's have some very interesting details,, IE 1 second @ F 2.8 exposure,,, ummm how can that be,,, thats what i use for mine,, with 150 watt,,, sorry but I call you on this detail...

unless someone can explain this from a photographic point of view and prove me wrong,,, I will then stand down..

sorry but if you come here and poo poo my poor little 150 watter, I have to respond in kind,,, but fairly,,,

This is interesting, because it means that one of the main improvements that should come from the 150W lamp, is a better focus of the picture. Yet if I'm not mistaken, nowhere in this thread Elken has said his pic is now more focused. I think the main improvements he claimed were only about better colors/contrast.

Elken,
Have you considered the following theory, that might explain why you get better contrast with the 150W bulb ?:



Look at your room, you have white ceiling practically touching the screen. I guess that you have white walls in other places close to the screen.

All these white walls reflect light from the screen, back to the screen. So, when you project an image on the screen that part of it is white, and part of it is dark, then the light from the white parts, hit the white walls, and come back to the screen, and hit the dark parts of the image on the screen, so the ANSI contrast is much reduced.

There is a reason why commercial theaters have walls painted black.

Now, it could be that when you use a dimmer bulb, you get less reflections from the walls, and hence the dark parts in the image on the screen are less polluted with reflected light, and hence your ANSI contrast increases (assuming we are talking about a non-linear system).

You can test this theory in several ways. First, get the 400W lamp back to the projector, and then you can:
1. take the lamp further away from the fresnel, so less light will reach the pj lens. This will dim the pic on the screen, and you need to dim it to the same lumen output you get with the 150W bulb.

2. another option is to buy a neutral lens filter, that reduces the light from the lens, and put it on the pj lens. You can buy this at a store which cells cameras. You should use a filter that cuts 50% of the light.

3. Build a simple shadow-box around your screen (it's a 2-3 foot black tunnel that you build around the screen edges, and this way most of the light leaving the screen to hit the ceiling and other side walls, will be stopped by the shadow-box).


steve_TO said he is going to do an experiment that will also help in this regard: he is going to watch a dark image both using his LL pj, and with an LCD monitor (hopefuly same model as the one in his pj), and look how much detail is lost in the pj image. If a lot of detail is lost, this again could be due to wall reflections destroying the ANSI contrast.

I think AV noticed it from going from one 1200w small arc to another smaller arc. But I know from a 55mm to a 24mm ushio, way way way better. I noticed it most in the small white letter boxes. If I look at them with the ushio, almost perfectly in the white square, no overlay, but some. The 55mm has a lot of overlay, looks like almost a double picture or something. When I had the 71mm arc, even worse. The smaller I go the better. I am almost to the point of running the 575w double ended inside my small projector, and 1200w in the large projector. I also can run smaller reflectors, which probably makes a difference as well. I personally think it is possible the reason ELK thinks it looks so much better, is that the color is great, and the picture is alittle sharper as well, but only he can answer that.

Isn't this a matter of personal preference? It would be a perfect world if we can easily DIY our own projector with everything equal to a commercial projector such as equal contrast, equal brightness, compactness but yet beat them in afforadability but it isn't. We have made strides since the basic design but there is always a 'give and take' in comparison based on the resourses we have available. It's just a matter of each individual's preference as to what he/she is looking for and would expect from their homemade design.

I'd have to admit though since asking a few (5) people with which looked better between the pictures in my thread showing the 4200 vs 6500 color temps they all chose the 4200. I suppose the light spectrum offered by the ceramic arc has a great deal to do with this. Sharpness has gotten better since moving down from the 40mm arc in my old modeled 400w Osram HQI to the 35mm in the 400w Philips CMD but not perfect. As meidosoracing stated there is still a tint of doubling emitting around the edges on projection.

One of the nicest color lamps is still the S400DD, but that was so long ago, that I don't remember now how the reds were, but whites looked great. I went to the EYE BT-28 after that and was a little disappointed with the whites, but after a while I really started to like that lamp alot... (I guess after it broke in and got to it's rated temperature?). I went back to the S400DD for a while, but thought it was too blue after being used to the 4200K temperature. I also liked the Ushio PS T15 lamp (4000K), but it created a softer focus at the edges vs. the EYE BT-28. (which I attest to the fact the BT-28 had a smaller viewable area of the arc, meaning it saw a smaller arc, than the Ushio PS T15) I'm now fooling with the Osram HQI-TS lamp, and so far it is really quite blue, but it's starting to break in, and warming up a bit... (either that or i'm just getting used to it !) In fact the Osram lamp, which is supposedly rated 5200-5600K, is bluer than the 6500 T15 ebay lamp I picked up for testing... weird.

Elken makes a good point, in that any lamp will need to be adjusted so as to get the correct color of grey. Once this is done, colors should be more "true". For me, I leave my panel's RGB settings on maximum, but as I found out today, my controllers default settings are 255,255,255 for RGB (GA2 controller for the WUXGA panel). Any reduction in setting to these values leads to a dramatic reduction in lumen levels. I will stick to software adjustments as this does not effect the lumen output nearly as much.

more ponderings...

gs

Thanks for that. Good read on the importance of a short arc.

you can tell the difference with only a 5mm difference in gap size? so the 20mm gap ceramic gs speks of would really be noticeable?

You all make very valid points.

I personally would just have a very hard time trading in my 1000w "sledgehammer".

Some people do care about efficiency,as they should.It makes the world a better place in the long run.I just can't go back to anything dimmer than what I already have.

Now,if you can find a <1000w lamp that will put out over 900ansi on my 120" screen,I would buy it and love it.I just don't see anything less than a 750w accomplishing this in the near future.Commercial bulbs are great but they are expensive and don't last long enough.Big metal halides are inefficient but they are cheap and last a long time.I would love to have 900 lumens and be running at 300watts (with cheap and long lasting lamps) but I don't think it will ever happen.It seems to me the only thing that can conform to all of these criteria are lasers,not lamps.Although,I must admit,the color spectrum on that lamp is astounding.

Ok revision of what i had said earlier about RGB adjustments on LCD panel hardware from OSD control

with some panels the opt, might be 100% as is with these WUXGA screens and controllers

all other panels optimum adjusts are at 50% over that they have settings they call photo or movie modes,, but the saturation can suffer badly in very bright scenes,,

anyhow with the type that are opt 100% just simply backoff whichever R-G-B channnel til you get perfect greyscale, with no tinge of colour

No lamp is going togive you natural balanced RGB with all defaults set on windows software etc

( there is no such thing as a lamp thats too blue or red, unless its peak emissions are way out of range of CF in panel),, you have to compensate.. if red band,, green band,, blue band,, of emissions were all at same peak value,, then natural white would occur....

this is how you set the "colour temp" of your screen, if you dont,, you will be pushing buttons till the cows come home,, heheh so to speak

ohhhh when you do this make sure all the windows settings are "DEFAULT",, then adjust your windows setting after LCD adjusts

also POWERSTRIP, gives you a whole lot of power adjustments, IE individual gamma for each colour, offsets for each colour,,, but hehhe dont use it till you have panel done first, with all windows defaults, then powerstrip,, if you want real fine control...

NOTE:: powerstrip wont work with some players such as Media Centre,, due to MPEG encoder used

Okay elken,I'm Sorry.I was WRONG to judge so harshly.

You could say that I'm a little biased(Hulk Smash!).

I just reread this entire thread and I must say that I'm very impressed with this tiny bulb.

Although I still don't understand how such a tiny lamp can create such a good image.

Great Work!!!

P.S. Radium(a german company)makes a 250w version

Thanx,, hehe dont worry I bought this thing thinking it's just a science experiment,,, but was ummm to say the least, surprised, especially considering the panels we use as compared to little ones in com units,,

light photon's are surprising in how they work,, play with them nicely, and they give hehehhe

I wonder how many ceramic arcs I can fit into one triplet?.......hmmmmmmmmmmm

Priapism?

back to same problem using multi lamps

however two lamps using a combining prisim would work

thats four 90 degree prisim's that end up looking like a cube

heheheh that would accept three lamp sources too

"Three,oh,it's a magic number....."

School House Rocks!!!



Now,where to find a combining prism........

EDIT:I know,I know......defeating the purpose of using a 150w lamp.
I just can't help myself sometimes.My dad says that I have a "lead foot".

here's one,, but apart from that it also can be a light recycler

look at laser angle to cube,, then see two spots on paper,, the prime right spot is same intensisty as without cube,, the second spot is recyled,, change angle of cube and they converge to one spot,,,

Click to view attachment

hehehehehehehh,,, Now I ask how does that float the boat mmmmmm

secrets many secrets and even more secrets

however that is with a laser too...

Light Recycling.........Fascinating!!

Are those acrylic prisms?

hmmmm I think my thinking on the combining prism is flawed,,,

twell twas a good idea at the time... maybe,,

Wow just finnished reading the whole thread twice! I know I will be using the bulb for sure. Better picture and cooler which is a bonus since I will be using a small screen and small enclosure.

I found a place in the UK that sells them but they dont state the color temp only Warm WDL and Cool NDL to choose from. I dont know which to pick if any.


Whttp://www.commercial-lamps.co.uk/acatalog/Metal_halide.html

WDL = 3000K = 830
NDL = 4200K = 942

so get the Cool NDL

Cool NDL = 4200K,

LOL!, I didn't know there was anything warmer than 4200K.

Elken,

Please lookup and read US patent# 685776.

Not sure if anyone believes you here, especially after I have explained that longer arcs than 30mm will not work. By the way, you ever gonna answer some questions that I asked, and then disappeared for 5 months? How can you know your lumens your light puts out, your color 5200k, but can't tell us any lamp numbers. Data sheet? You said you had one? What is the numbers on the actual light, and don't say it doesn't have them, because we all have halides and know it does? Arc, 80mm plus the white ends 100mm not fitting into a 80mm lens. A doublet if anyone has used them know the pictures posted weren't from that. Also, AV has tested your type of reflector, no gains. How is it that you didn't know what you pulled off your lcd, I think you said "I'm not sure what I pulled off, but I pulled off like 4 layers." Then all of a sudden you had pooof, "My dad and I are selling polarizers." funny how you can say one thing, not even knowing what a polarizer is, then saying you sell them when you got caught. "You must have magic grits." My Cousin Vinny

Here are your exact quotes: "I did pull quite a few layers off my panel before I actually knew what they were. It still works though." Means you didn't add polarizers.
Then:"I removed 4 layers 3 of which had polarizing properties which mistakenly led me to believe I had removed the rear polarizer."
Finally: "I did the same thing and mistakenly told everyone I had removed the rear polarizer. I didn't. It was just a backlight enhancement layer that had polarizing properties."


Bye the way, you ever gonna send back AV's wide angle lens he sent you? I think people here will consider you stealing that, since you won't. Remember, you were suppose to take a picture of your magic projector at work. Then here is a post from someone else for Benjimatts lcd.
"i'm almost afraid to ask...

I thought you were getting some LCD from Elbe with some "special polarizer material" ? What happened with that?"

Never arrived

wow been missing my threadism,,,, just watched firewall on big screen,, great movie,,,, ummm interupted for two hours by my favourite girl..

I even bought a new jug, and crock pot,, electric,,, cause my jug blew a phoofer valve last night grrrrrr,, down a 150 bucks now.. but mmm nice coffee again, and a stew tomorrow night,,, heheh gotta use new toys,,, even had time to go shopping for an elliptical mirror,,, mmmm lighting shops have alls orts of offbeat possibles, now having a small profile lamp

and my place smells all nice and vanilla heheheheh got sick of bacco smell,,, yeah yeah bought some of these plug in ceramic deodourisers,,, damm fangled new technology,,

gawd even saw a robot vacuum cleaner in my local ALDI pamphlet,,, damm did I miss a few years along the way,,,,


edit,,, as soon as you earn a bucket of money someone finds a way of parting you from it,,,, grrrrrrrr

Murphies law,, and when murphy is on hols,,, rafferties rules take over,,,, damm such as life ( quote from Ned Kelly just before they hung him )

yeah yeah I know way off topicism

Not sure if there were a lot of people who wanted to get together to buy these lamps, but atlas has them for 35 each... but you need to buy a case of 12.

http://www.atlaslightingsupply.com/MHCeramic.html

Here is a pic of 2 Osram 150W Ceramic lamps I'm trying out.

Click to view attachment

Osram HCI-TS 150W/942 powerball

Am gonna do some more research, but 400watter may be good.
http://www.osram.com/pdf/service_corner/10...rball%20400w%22

According to Osram brochure, Powerball model is better thanks to the round arc tube wich provides uniform light in all directions.

Yeah, if we can get the 400w one, that would be about perfect. Small round arc.

That's cool. Is there any info out there about just how the arc tube chamber "shapes" the arc? It has to be w-a-y better to squish the arc into a ball instead of a line. Has anyone a through-a-welding-helmet picture of the arc in one of these ball chambers???

Dur, I also wonder that. Wonder if the light uses even the outter edges, or if it is more of an inner ball of light.

I dont think it "shapes" the arc, its still a line.

I haven't been around lately, so I haven't read all this, but let me ask a question. Is the arc just an outter layer of ceramic, and the inside is exactly the same as a normal halide with the gases in the middle etc? Or is the actual cermic lighting up, and it is mainly solid full of ceramic? Also, at 12000 hours use, I would guess running the 400w at maybe 500w wouldn't be too bad. Anyone up for a group buy on 400w from one of the guys here in the UK? Thanks

Ceramic MH lamps refer to the material the arc chamber is made from. It the chamber still contains metal halides, etc. The biggest difference is that ceramics are more uniform than their quartz counterparts, so repetability is better, ceramics are not as prone to the chemical reactions within the arc chamber so they do not wear as badly, and they can withstand higher temperatures. The ability to withstand high temperatures, means they operate at higher temperatures, but this aids in stabilizing the color output of the lamp, it reduced wear, preserves the lumen output as well. I'm sure the actual mix of halides in the chambers do vary slightly based on the size and temperature of the arc chamber, but many lamps have slightly different mixes to get them to have certain characteristics. Once heated up, the entire ceramic chamber will glow as does the current quartz arc chambers. It would seem to me that the ceramic chambers would not be as "clear" as the quartz, but i'm not too familiar with the properties of ceramics at high temperatures...

gs

Funny, I was really bothered in some nondescript way by that first picture of a red-glowing ceramic. How DOES that work? I mean - it's not transparent for crying out loud!?!?!

Its easy to get something to glow. Put enough energy into just about anything and it will glow, even rock. My question is:
If this is a ceramic chamber, what does that do for our rear reflector? Since we try to bounce the light back through the arc, wont it stop at the ceramic chamber? Or at least a portion of it?