Do you have to take the readings from the center of the screen? I think the jumping and holding that “thing" in your hand might start a stampede.

At least it is not my laser temp gun

ummm..yeah, I'd be careful using that in public.... as a side note, my new light meter came in the other day to work(things have a tendency to disaapear off my front porch and there a pj I've always wanted to measure the next aisle over...so I start measuring it(250 lux center screen about 2 sq mtere so about 500 llumens..more than enough and not as high as I had thought it would be) anyway I'm measuring it and I hear a bunch of laughter I look up and at the end of the aisle is my bosses office and theres like a meeting goign on and everyone is laughing and pointing at me..sigh.... well, I have a rep as somewhat ummm.."different" anyway... keeps the prols amused...

What wattage was there PJ? They use the screen for daylight viewing?

That would be funny to see.

I need to move my light box back an inch or make the box an inch longer. I had one more idea that might be easier and better.

Move the fresnels foward an inch. I puled the fresnel sled and cut 1/4 inch off the front spacer between the LCD and the front fresnel. The gap is now about 20mm. I have a 550mm .05mm fresnel so I should not see any fresnel rings and I didn't.

Befor I did this I moved the 550mm to the back of the LCD sled which is only about 15mm fron the LCD. I could see some fresnel rings but my light pattern was now perfect. I had also moved the 330mm into the slot where the 550 was and this reduced the spacing betewwn the fresnels from about 40mm to 30mm.

This gave a perfect light pattern and let me move the light box more than 20mm foward? I can only think that the large space I had between the two fresnels was making the rear fl longer.

So I have a new plan.

I have changed the air flow from having the air go from between the LCD and front fresnel then down between the lexan out the bottom to having almost all the air just go out the three holes I driled in the top.

I am going to make a new fresnel sled that will have smaler spacing between the front and rear fresnel maybe only 8mm or so and I will change the air flow to have all the air just go from the bottom out the top through all the fresnels and have the lexan be the seal from front to back.

This will give me my inch and give me better cooling and let me move the light box foward a little if I want to.

With the freanels set right this will also let me move my reflector slightly closer for more LUX.

The screen after removing 1/4 of an inch from the front of the fresnel tray.

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And with the LCD on

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And the thiner fresnel tray.

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And the triplet image going into the triplet.

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It is hard to see but the light cone is smaller than the triplet by 30% or so this photo does show a light pattern larger than what it should be if there was no light spread by the antiglare

I did LUX readings and they are about the same. Contrast was 189 LUX white 31 black with stray light =to 20

I need to do the contrast test at night I no longer have a blind in the room so there is a lot stray light.

Wached It's a bugs Life tonight after todays adjustments and the light pattern is fairly good now It seams a little dimer but I did not test it.

My three year old loved the bugs.

The 16/9 fit the screen nice so it was almost 126" x 64"


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My LCD may eat light but it makes a nice picture too.

I have a tripod or three but I still have done all the shots by hand.

Looking to find an inch of adjustment for the light I moved the condenser lens to the inside of the light box. This was easy to do and gave me about 30mm mor adjustment which was more than I needed to get an even light pattern.

The light pattern is fixed!!

The bottom of the screen is yellowed from the sun so dont look at that part.

I also wanted to see how making a dark spot on the reflector would help to get rid of the hot spot in the middle that you always get when you push the reflector a little too close so I painted a small black spot with high heat black paint right in the middle of the reflector and let it fan out on its own.

This worked OK the peak in the middle is not nearly as high but is now vary wide about half of the screen. The fall of is not too sharp either. I think a slightly larger spot and just a little closer I could boost the light hitting the outside 80% of the screen and not get a hot spott in the middle. Cool.

The screen is with the reflector set a little closer than zero (where it is making the same size reflection as the lamp arc) with the reflector with the black spot.

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The LUX is up little too.

The screen was 1.8m^2

198 257 181
184 243 200
148 232 202
avrage of 205 ANSI of 369. There was a fair amount of stray light today. and this was with the LCD on whis is 20% lower than with it off.

I might make some more changes to the reflector by replacing the black spot with just a small reflector or just round disk.

Hary Potter tonight.

AZ those screen shots are amazing!

Definatly an aspiration to us all.

Well Thank you. It has been a lot of fun and just the type of stuff like to do.


After the last adjustments it picture is even better in fact it is the best so far. We replayed A Bugs Life due to popular demand by the three year old.

The LUX across the middle of the 123" wide screen was 65 in the middle and over 50 all the way to with in 10" of the edge of the screen. At 4" from the edge I still had 45 LUX. This is vary flat and for some reason the color looked better, maybe the flatness helps to make the color look even. I like the hungery bird.

during lightning.

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I'm hungry

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It was cool tonight around 70deg outside, the little one grabbed his coat and this gave me an idea. I had 20 extra feet of the 3" flex line for the exhaust vent so I hooked it to the PJ lamp exhaust to see if I could let the heat go under the swing bench we all sit on.
Almost no air came out so I need to improve the cold weather heating system. It could get down to 60 deg soon and I might think of hot coco.

I have a nice 120v 120mm fan I think I will put in housing and use some 4" flex for heat duct under the chair. It would be a shame not to use all that heat.

I also hung a piece of black out (bo) cloth down the center of my screen to see the difference. My wife and I both liked the blind vinyl screen better. The bo cloth looked grey/blue it could be adjusted but it was just a test.

More bandwith The whole setup again with the 300 watt spots on. I did have a dimmer on them which was nice to start the movie.

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The BO cloth on the screen inside.

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left side is the blind the right is the BO cloth.

A white screen

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And the girl who likes to lay on her back. In this shot her dress is a little yellow on the blind but much whiter on the BO cloth.

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(Edit) I didn't like the last picture so I using the pictures from Harry Potter after the antiglare strip.

I'm using a different PC and this is after the antiglare strip. I was also using power DVD instead of win DVD which is the only player that will not skip on the 500 MHz laptop.

The new (old pc) has a MX4000 card and will at least let me run native 1280 x 1024 for the first time! I have 6 pc in house at least one should play a DVD.

The colors were vary nice and the black levels were much better but I could not get the movie (Harry Potter) to be bright enough for some reason. Power DVD v5 kills win DVD for quality and has more features but does not have a fine zoom or fine stretch so you can leave it 16/9 or have it pan & scan to 1.8 to 1, which is way too much. When I get a larger screen it will be taller, so if I wanted to I could trim the edges a little bit to get a few more lines of horz rez.


The windows desk top was vary bright but the movie played on the dark side, it looked great like some people set there TV's when they watch them in the dark. This was fine because I was outside at night and it is dark out at night

Some pictures.


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I don’t know why the movie played so dark mainly in the dark seines. It all looked good and some seines were nice and bright but I would like the levels to be a little higher. I will try the old laptop and a few other settings to see if I can gain control of the brightness levels.

This is a kinda bad wiring diagram of the two ballast setup. The main thing to look at is the input from the outlet can not be reversed. With one ballast they will run with either lead on the hot wire but if you reverse the inputs in a two ballast setup the output will be 180 deg out of phase with each other and the fuse will blow fast, so for the input com goes to com and the 120v lead goes to the 120v.

The igniter need to be removed from the second ballast. You start the lamp with the 600 watt ballast and then switch in the second ballast.

For this setup the 600 watt ballast has a 55uf cap and a 10uf cap in parallel. The 400 watt ballast has a 55uf and a 7.5uf cap. I did not show the caps.

The output is like the input, com to com and lamp wire to lamp wire. You can see the switch for the second ballast. Both ballast turn on when the main power switch is thrown but you switch in the second after the first lamp strikes up. I also turn the lamp on "low" for a little bit before shut down to let the lamp cool down slower.


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I know I said I would wait for a hundred movies before I striped the LCD but I could not wait any longer. 10 is almost a 100 any way right?

I wanted to redo the LUX test with and with out the LCD anyhow.

First the strip was easy I soaked the LCD with three paper towels for 4 hours and used a razor blade and a 10x lope to lift the antiglare. Before I got the towels wet I made sure that the LCD was level so the water would not run off. I left the LCD in its frame there was no real reason to remove it.

I did spray the area with anti static spray first.

The antiglare came off in one piece with a slight pressure. There was some glue left on the LCD so I reapplied the wet towels for less than five minuets and it came off fairly easy by buffing with a vary wet paper towel then switching to a damp paper towel.

I used distilled water I don't know of it made any difference.

The LCD is fine after the strip too.

The last time I did a LUX test with and with out the LCD in place I didn't write down the number so I think I was right but I'm not sure so here a three point test.

The screen was about 50" x 40"

With no LCD and the LUX meter on 10x

711 972 684
Average is 789

Yes I almost have 1000 LUX in the middle of the screen!

The screen is 1.97m x 1.016m = 2m so around 15780 lumen.

I then reinserted the LCD.

With the LCD off and the meter still on 10x

40 52 40 = 44 x 10 = 440 x screen of 2 =880 lumen.

The LCD is dimmer when on and I set the meter to 1x

323 419 341 = 361 x screen of 2m = 722 lumen.

I then found a setting on the LCD for "Movie" which made it brighter.

346 450 367 = 387 x screen of 2 =775 lumens.


I will use the off reading for the LCD so 880/15780 x 100= 5.5% LCD transmission.

And then for the on movie setting.

775/15780 x 100= 4.91%

My ANSI is higher because I did not take 9 readings but 3

A few more of the strip.

Nice job of sled, and strip Ariz..

WTH.....WHERE ARE THE NEW SCREENIES WITHOUT THE A/G????

I replaced some in a eddt but I always have more.


This one I did not pause so I got a new key frame.

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This is just what you see and wee all like it.

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I now have too much contrast The really bright frames ar a little too bright and the dark frames a little dark. I need to use the old laptop to see if the it is the sourse or not.

Hi AZ!
Just caught up on your plog, you have been busy! Looks great! Makes me want to build another PJ. I bet that baby is really vivid even at 120!
Fine Job!

Terrific job, AZ

"I now have too much contrast"

Seems you are getting pretty marvelous results

Hey AV, do you have Shark Tales? If you do can you give me a sample screenie of your Crazy Crab scene like the one below. Mind you this is projected on a Dalite HighPower 2.8 gain screen. I'd like to see what your higher lux pj is putting out on your current screen.

A/V,

Those pictures are looking mighty nice.... I'm getting the itch to build.

Very Impressive!

Fulcrum

Strange you would bring up Shark tales; we just put it in the Netflicks list Sunday so it will be here soon. I forgot to send out Mondays movie so shark won't be here until wed.

Netflicks rules they have 100 X as many movies as Blockbuster does. We went to blockbuster the other night because the movie I picked out for Dad to see was the wrong one. Half the shelf was empty and the ones they did have were $4.00 each. I can tell you Gost is not worth $4.00. The other disk was so beat it barley played. Thanks BB

Thanks for the kind words on the image. Any one can do it, get a high cotrast LCD and a high CRI lamp. I am looking at a larger screen too, as soon as I get some samples to see. I like the plastic a lot better than the BO cloth and it is about the same price. ( my screen is the ruberized vinyl ) going for a 90" x 170"

My big bummer right now is the screen is a little smaller than I planed so the PJ is closed too. This made the kids sand box be in the way so now I need to move 1000lb of sand to free up some seating for the extended family to use.


I live in the middle of Phoenix and some times we get get big old barn owls I have heard them but not seen one for a long time. Last night one landed on the street light and I got a picture of him. He must be looking for the roof rats. Its around 2 feet long, Good hunting.

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This makes me think I should remove the poison traps we have out for the rats and just use the old snap traps, there the only ones that work any how.

I was looking for some larger screen material today and a local Guy said he can get 96" wide rolls. He said he will find out the exact amount soon.

The bottom of the eve of the house is 92" from the ground so if I want the screen to stay under the roof it can only be about 90" tall. My current screen is 64" tall.

So I did a test projection on the side wall of the house which is white brick about 8’ x 16' in size. I wanted to see if the screen door and pixels would start to look bad at the larger screen size and how the brightness was.

The brightness was fine and I was suppressed that I could be a little closer to the screen and not see any major screen door or pixels.

I did have a 2' x 4' piece of BO cloth taped to the wall for a test of what the real screen would look like.

The kids removed the BO cloth fast and had fun seeing everything so big.

It looks like a 7 1/2'X16' screen will look fine and we all will have a little more room to move around. I moved the sand box tonight too so we have seating for 8 to 10 people if we need to. The screen will be almost 200" diagonal which is a little more than I first planed.

Some HD stuff is even wider than 16/9 and I may leave a gap at the bottom of the screen for speakersI'm also going to paint the overhang white so I can see the windows desk top..

I like the setup now the one speaker that is behind the screen I just flipped upside down and the mid and tweeter are below the screen and it sounds fine. I could make a small set of speakers and wrap them in the white screen cloth and just set them in front of the screen on there side. The one thing I like about the Junkers I have out there now is I just leave them outside all the time so it is one less thing to setup for a movie.

I like the sound from the free junk RaidoShack three way speakers with the paper tweeters and 12" woofer and paper mid range. The receiver I use to power them is one I have always loved the sound of it a Quaderflex 2200R it is vary smooth but only makes 22 watts with one big TO3 can transistor on each side for an output. The high efficiency of the RaidoShack speakers means it is just loud enough and even has good bass (not real bass but movie bass) Sometimes light paper cones can sound good.


Some shots of the bricks. There is a tree in the way so I has to set the PJ off to the side a little.

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With a little help from my freinds.

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I was using the laptop again the the brightness is back so the dark settings is just the other computer. I don't have a final computer to setup for paying DVD's yet. I may build it into the PJ box or just a free standing box. I got the VLC streaming media player but have to learn how to use it.

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(edit) Sim: I don't have Shark Tails comming, we have Buzz lightyear the movie, I will put it on the list but it will be a while

Looking good AV. Is the output difference between computers due to a hardware or software difference? I know that when I upgraded from a geforce2 to a 6600GT (using same 19" crt monitor) it was much brighter with better detail. On the other hand, it's always hard to find all the little software tweaks to make sure that two computers are the same as far as all that goes too....

Looks good AV, so the lumens are really good. I bet a 150w ceramic would be better Good work, and keep on keepin on...

*rimshot*

So how much does a home movie cost?

1200 watt PJ runing 2hr about 3kwh

1500 watt electric heater 2hours 3kwh

PC 300 watts 2hours .6kwh

Popcorn 1500 watts 5min ,1kwh

Stereo 150 watt 2hr .3kwh

Yard lights 900 watts 1/2 hour .45kw

Total KWH used 7.5 @ $00.10 per kwh=$00.75

So a movie cost less than a buck.

If any one wants to re-run the numbers feel free to.
I just made this up but it should be close.

Embedding a family memory in your children that will last a lifetime and lift them up in the dark with memories of a bright shining projector moment: Priceless

AV begins his 3000W projector build using ...

Nah... too small.

A gaseous high pressure laser focusing chamber?

I’m am looking at getting the 2000 watt PJ up and running with a 20.1” 1680 x 1050 LCD This looks like a lot of money and every part is not common. Rare fresnels, triplet, condenser lens (have not found any thing close) and lamp. I have the lamp running now and it looks great just like the little HQI 400 at 550 watt just 4 times brighter. It really is almost a scary lamp. I guss I could overdrive it to 3000 watts just for fun I have three so if I toast one I got backup. B)

I may not buy any thing until I see how the larger screen looks with the 1,200 watt system. The 15.4 LCD may still be a better way to go….thinking…

Got the first test screen cloth today from ebay seller b-a it is just BO cloth and more money than LL BO cloth. Still looking.

Yeah, just don't toast the enclosure and yourself in the process, alright?

http://cgi.ebay.com/USED-Paul-O-Abbe-doubl...=item7582474673

HI, aren´t it too much? I build my proyector at 1440x900 2000:1 5ms LG19WT wide with a proKit Lumenlamp and 400w osram which rise about 200 ansi wiout condenser or reflector (at last). This config with a 1200w may rise about 650 lumens ansi or 2000 w may increase to 1100 lumen ansi. It not very bad. See too 1200w proyect at : http://www.lumenlab.com/forums/index.php?showtopic=9125
About Hi resolution, from 1440 to 1650 and from 900 to 1050 its not a big difference but it is in contrast and in problems you will have to make it works correctly.
I had to made a lightbox as big as LCD and put the twos fresnels inverted, of course I removed antiglare and repose polarizer film. It was the only way to iluminate all the frame, because putting it in right form only appear a big center circle good lighted and many ring of light around: no light at all in corners. Lumenlab say Pro Kit is valid to 19´´wide but it is not correct because you need to cheap the kit to make it works. I stimate ProKit only iluminate well an 15´´TFT (corner uniformity lighted). So I have to take the light from flat side of 220 fresnel, pas to second fresnel 550 so closer than TFT has to be located only at last position, in front of 650 triplet. The second fresnel are inverted too and must be very closer to first one because the far is the more barrel focus deform. And in this configuration I see all focus at all, it perfect, unbelible I can focus whole screen at all, with a precision which I can belive and no deform at all, pure square, ligthed, and focused corner. I will put photos in 19´´ stereo 3d proyector Plog as soo as posible (had to allocate at garden but it´s rainnig this days 5metersx3meters silver screen) .
Bigger LCD bigger proglems exponencially, remenber our proyectors are universal proyector, may proyect any thing Diapo, or in an pair of years a much better new TFT so don´t spend too much in a bit of pixel more which has no important becouse there isn´t many HDcontets until today. Invert in good lenses and good contrast. There is coming new LCD at 1920x1080 with 7inches..... http://www.clubic.com/actualite-39607-lcd-...uces-sanyo.html (only 500:1)

A/V,

I've got a quick question....

Since the corners of your picture are slightly out of focus (because of triplet), which way would you move the triplet in reference to the fresnel to get them in focus (ignoring the image's focus at the center)?

I'm guessing you would move it slightly closer. How much closer? As much as 10 mm?

So do you think a frame that bows the fresnel would help?

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Cheers!

Fulcrum

I have thought of the same thing. By using a vacuum plate and a heat lamp you could curve the Fresnel fairly precisely. I need to recheck to see which way you would need to bend the lens.

I have an un-split setup so it will not help me but for a split system it may help.

How far from the center of the sreen does the image start to lose its focus? If the blurry part is really only in the corners and not so much near the middle of the edges then you could probably get away without having to vacuum bend the fresnel, just frame it like Fulcrum mentioned. This wouldn't create a sphere shaped bend like the vacuum but it would save you from purchasing another huge piece of glass and would make the process user friendly for the vacuum timid.

I'm fixin' to start my first build with a 17" 4:3 monitor and an 18" Besseler triplet. I'd like to use it as a computer screen so this mod might be the fix i'll need...

Dave

AV, I've gone thru your thread looking for any closeup pictures showing your projected corners with your 17" panel and the 18" triplet. Would you mind providing some?

Sure, its a little hard to be perfect because the screen has small waves in it and I have not made the LCD to triplet as perfect as it could be. For movies the focus just does not have to be ultra sharp. I like the slightly soft focus in the middle any how, this makes the outside sharper.

The nice thing about a large screen is you sit further away so small defects in the screen you just dont see.

I Think I found a good screen material of smooth 100% white vinyl for a 96" x 180" screen. waiting for a sample.

If it's the right stuf I may sell it to everyone. It is better than BO cloth and should be the same as a 1.3 gain daylight screen.

I have the same focusing issues using the 18" trip with my 15" panel. I tend to do the same - focusing the corners more then the center or in between both and it is not noticable unless your of 5' away from the screen. I just want to see how much more unfocus will it be if and when I do go bigger to a 17" panel.

It would be a blessing if we could figure out the focus problem with these 18"s, wouldn't you think......hint, hint

BTW, I also have 2 of these opaques as well. The newer one will be replacing the current I'm using since some of the lens on the current have chipped on the edges when cleaning and briefly playing around with the lens distances as elken did for the pro trip. I'm thinking on full disassembly and mount all three lens seperately for tests. But it's going to be kinda hard to adjust using full elements in my rig. Have any ideas?

Same thing I have two 18" also with an old and a new one the new one has chips. For me it looked like the old one had better focus they are different just the same FL.

There was a thread on the focus of the Buhl for a little while. It was kind of like trying to get Elkin to do a lux reading

Speaking of LUX I still need to do a full LUX test after the antiglare strip. I got 700 ANSI with the three reading test last time but that is not really fair.

I was surprised tonight that I could start the movie before it was dark! The sky was lit but the sun was not on the screen and it look fine for the kids. That way we can get done before it gets cold, it migh be below 65deg tonight!

I was going to use the new 18" triplet and make three lens slides out of wood and just adjust them with a LCD and lamp setup to see if a slight adjustment will make them work better. I just have not had the time to get the test rig going again. There is a chance that mixing the old lens and new ones might give a slightly longer fl and better focus the lenses are different.

From that thread I don't think we can improve the lens much with out making new problems.

Some people want perfect sharp corner to corner focus and I think that’s what the pro lens is good for. That said I am totally happy with the focus on the 17" LCD and any 16/9 movie it is bright and fairly sharp right to the edge.

I can still go pro and all of the lamp arc will fit and I won't loose any brightness, I will wait until I do the new screen so the PJ can be just a little further away from the swing bench. Right now if you swing too far the bench hits the PJ so I would like just a little more throw.

As for the curved Fresnel when the center is in sharp focus you have to move the triplet in toward the LCD to get the outside sharp so the Fresnel would need to curve toward the LCD and away from the triplet.

After the movie tonight I did some test shots and even used a tripod for the first time.

I had to move the PJ closer to the screen to get a 4/3 image to fit and I was still a little too fat away ( there is a hole in the concrete from a tree) so the top is not all there. The top is the same as the bottom so that is what you will see.


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Can't tell much here . I did set the focus with the middle of the screen vary sharp so all of the fuzzies will be the sides. My rear fresnel holder cuts the light off just a tad on the right side so it looks soft on the edge the left is sharp.

The windows desk top I really need a jpeg of black letters for full screen.

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The start button looks a little better in real life but not perfect.

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I had a contrast pattern with numbers whis is always hard to see but is a OK test.

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I could do a better job of this if I has a full screen numbers pattern of black and white text.

Thats all for now. I have a few more pictures but I think the desktop shot is about right.


The screen was about 63" x 68"

I think bending the front fresnel towards the LCD will cause barreling.

DJ

Well I never did a final LUX test with the antiglare striped so I did that tonight. I also did a contrast test with a full black screen and a white screen.

I do have the light entering the side of the LCD at the edges like other have had I don’t see it during movies but I might during a night seine. I don’t know and easy way to fix this? Maybe some black paint on the edge of the LCD?

A picture of the black screen.


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The white is over exposed so in real life it looks darker.


The contrast test showed 2 LUX black and 278 LUX with 1 LUX stray light. I don't know how they get 3000 to 1 but it look like I'm around 278 to 1.


The LUX numbers the screen is 60" x 47” or 2.36m x 1.85m for a square of 4.366m^2 ( edit I did that wrong the screen ia 1.8M^2)

240 306 202

227 278 240

178 262 220

Average LUX of 239.

With a screen of 4.366m^2 that is an ANSI of 1043! ( edit make that 1.8 x 239 for a ANSI of 430)

Well I guess the strip helped.

I did get the LCD set right so that was the main reason the LUX reading were low for the first test. No wonder I think the screen looks nice and bright even at dusk. This thing kicks out some real LUX. Sunglasses ON

That's a good number to see. Nice to see you happy with it. I'm scared to see
what else you come up with next. Or is this enough for you?

I keep looking to see if I made a mistake in the numbers, is the square meters for the screen right? The LUX is right and the screen size is right the stray lux was 3

Ok I found the mistake the screen is not 4.3m^2

The right way is 60 x .254= 1.54M and 47" x .254= 1.2m so 1.54 x 1.2 + =1.8 m^2 x 239 Lumens = 430 ANSI. Now that makes more sence.

Only 430 ANSI I guess I really do need that 2k light?