We want your project to be a success! If you're having trouble and need help, this is the place to ask.

Hi B. I really like the way this forum application works and its options but I really find on thing annoying and I was wondering if there is any setting you can change as forum admin to prevent that to happen. The problem with the forum feature is the following:

I usually check, almost daily, for new posts to follow the development of the projects and keep up to speed with all the tips, instructions, advices and warnings regarding this DIY project. Unfortunately more than once my browser for a reason or another quitted on me therefore I need each time to relaunch it and continue my reading task...well at the moment I go to hit Read New Posts the forum application remembers the when I last connected, therefore assumes I already read those that were "New" posts during my last session (before the broser quitted) and will not report them anymore.

In such case I lost that list of new posts and I will not be able to read them unless I go search each topic and see if there have been new replies to the thread, which is quite a tedious task. I though about doing a search for posts 7 days and newer but I get results only using a precise keyword. If I use a widcard such as * or a keyword combination the search tool just reports an error.

Thank you (if anything is not clear please let me know )

Hey FreakQNC...

That is annoying... but I don't think there is much we can do about it (at least not without a great deal of hacking). You could try "Today's active topics" at the bottom of the forum home page. It's not as convenient as the "New Posts" feature but still better than nothing

I'd have to take a look at the code, but I'm fairly sure that it would be relatively easy to put that "Today's active topics" link up top by the New Posts link..

Thanks oog, that would be great!

Also I was thinking that we could have a customers section (with PW access) where to organize all the ideas, tips and info on this forum in a more organic way... what do you think about it? If needed i could help (webdesign and graphic and some HTML=can do)

Brain, (or others)
q on focal length.

from reading the plans, i take it that the FL's of the different lenses are pretty much a set value, with only slight adjustments. am i correct in understanding that the PJ would then have a set distance from the wall, and a set size for the picture?

if that is so, for a a typical 15" lcd, what is the distance from the wall needed to get a focused projected image, and how big an image would you get?


thanks

Actually you're only partially right. The projection lens can focus at a distance of 320mm or greater from the LCD. If the lens is at 320mm it is focused on infinity which means your projection would be infinitely huge. The closer the screen moves toward the projector the farther away from the lcd the lens moves. In our usage the projection lens is going to be 330-350mm from the panel. You could have your screen only 2' away from the projector and still focus the lens.

I'm confused. If the lens is stationary. How does is move. Are you refering to the movement of the lens for focusing???

Yes. Depending on how you use your projector you would either have a large amount of focus or a small amount of focus. If the projector gets moved a lot for varying screen distances you would want about 2" of movement in the pj lens. If you have a static arrangement you would only need about .25" of movement.

admin or mods

a few weeks ago i saw a non-pinned topic someone had posted about their progress on stripping a benq 567s V2. it was a couple pages w/ pics. i can't seem to find it now. could you tell me if it has been moved and where? sorry but i can't recall the member.

thanks

Evo used the benq 567s v2 in his projector. I dont think he showed how to strip it, but does have pictures of it stripped.

Only strip post I remember was a LV. http://www.lumenlab.com/forums/index.php?s...78&hl=stripping

my bust guys it's a 557 not a 567. thanks anyway for the help info. i found it again under:

"The Science and Art of Video Projection -> Intelligent Video Projector Design - Protected forum - Buy the guide for access." -

BenQ FP557s version 2 Teardown (Pages 1 2 )

post is by sydneybird

FREND PLEASE TELL ME THE REASON WHY WE ARE USING TRIPLET LENS


CANNOT WE USE ANY OTHER FINE QUALITY SIMPLE LENS


AS I FOUND LENS 23X on surplusshed.com

will not this work?

also please tell me

how much focal lenght we need to project the biggest imgae with a short throw distance

as our triplet is 320 mm

instead of simple triplet if we go for a powerful lens we will be able to give our projector

bigger image with shorter throw distance

please guide me as im very new to this field and this is my first ever messege

lens of what focal lenght will be more powerful to project a bigger image with a short throw distance

will it be 50mm focal lenght or 400 mm focal lenght

Well 1st the tripley is a high quality lens, i have compared it to the vari focus used on other boards, and gives a higer quality as well as brighter image, If you choose to use another lens then you have to check what the field of view is for that lens to make sure you can capture all of the LCD screen to be projected. and 2nd. most of us want a longer throw not a shorter one, brain is getting a zoom type lens, larger Dia. with a longer throw distance which will allow us to move our projectors back further for better placement.

Hope this helps,
Joe

yaaa


according to kduki 's projector he said according to the laws of science

if the projecot is more near to the screen will result in more brighter and vibrant picture than a projector placed far away .........

for example projector 5 feet away from screen provide more lumen than the projecto placed 10 feets away from the screen

the field view of lens is no problem for me as i have find many lens with wider dia that can capture whole lcd upto the focal lenght

my problem is that any body have tested thee lens with a very less focal lenght

as im now having lens with 110mm focal lenght and appx 2 inches in dia

will that help me in giving short throw distance

for example in pic

if both projectors are eqquipped with same spares with same dimensions too

but with two dufferent lens

that is 110 mm focal lengh and the other one 330 mm focal lenght

see the pic and please justify and explain me

No i do not think anyone has tested any lenses side by side yet, and it is also correct, the closer to the sceen you are the brighter the picture and of course brighter means more vivid colors. And of course this would also depend on quality of your triplet lenses.

I would sujest you possible send the lenses to someone to test and take pics of findings if you do not have a projector yourself which i am assuming you do not because you would test it yourself... lol

here are my results at 8 feet away with the standard triplet lens.

http://www.lumenlab.com/forums/index.php?s...indpost&p=19304

Joe

You'd need a matching fresnel lens.

I put together the enclosure and put the fresnel lenses, LCD, lamp and the projector lens with pins and tape just to get a quick sense of what the results would be like. However, the output is nothing - light gray patch with some brightness on the fringe!!!

I know I must have done some miscalculation. But will there be absolutely no display if a position is off by a few mm? Is there a step by step way through which I can find the problem ?

Couple of things I noticed which might be important:
- If the lamp arc (placed horizonatal) is probably not exactly centered (say, off my 5-7 mm), will it cause the final projected image to blank out?

- The inner fresnel lens I got from lumenlab store (220mm) seems a little bit warped (little curved in the middle). Can that be causing the problem? Any way to fix it?

All suggestions welcome. I will call it a day for now!!

No none of those things would cause a blank image. It sounds like your panel isn't working, have you verified that it is?

I can see the panel working - it is hooked to my laptop VGA outout and is displaying the desktop.

So you are saying that I should get some kind of output even if I mixed up on the placement a little bit?

Thanks for all the help

Yes. Maybe you put your fresnels in wrong? The grooved sides should be facing the panel. Confirm that the shorter focal length fresnel is in the back.

I got it working. Projected an image from my laptop - depsite all the light leaks the results were stunning!!! I must have got the fresnels mixed.

Now I am building my enclosure. I want to know if it is essential to fit the LCD and the fresnel in such as way that there are no gaps around the side edges. If I find a way to suspend them from the top in such a way that the sides are not touching the enclosure, can the light leakage spoil the results?

I haven't still figured out how I am going to do it.

thanks
A

Yeah you don't want any leaks.

I am trying to define the parts for my py and have a couple of questions:

1; Any experience out there with the Wintergreen / 17-inch / 1280 x 1024 / Silver/Black LCD Monitor? Seems a good deal at 199 but need to know if good.

2. Where do I get the Usich lamp, what are its benefits and exactly what ballast go with it?

Thanks

Never heard of that monitor. What's a Usich lamp? Ushio?

Yes, Ushio.

We sell the Ushio lamp in the store. We have 120v ballasts coming in tomorrow or Monday.

Does the Ushio lamp also have a reflector, or can I use the one for the eye lamp with it?

Also, Is the Ushio lamp better than the eye lamp? Why?

Thanks

It has a much better CRI rating, thus colors jump out more, plus, the color temp is higher giving you more acurate colors. Yes you can use the Norpro bowl with the Ushio.

Removed to more appropriate location

I just received my 250w ballast and bulb. Unfortunately i have a coil ballast that says it's a m58/m37. my eiko double ended bulb says its a ansi rating of m80-does this mean i need a different ballast? Thanks!!

I just received my 250w ballast and bulb. Unfortunately i have a coil ballast that says it's a m58/m37. my eiko double ended bulb says its a ansi rating of m80-does this mean i need a different ballast? Thanks!!

It's been awile since i last got a chance to work on this, but it is done-sortof. I think my lense is incorrect. I'm working with a PSONE screen(5"), so how do i determine what my FOV should be on my lense? Is that number the "F:" ? I know the "FL" is the focal length. I'm jsut having a problem with a black ring around the outside of the picture. Any assistance?
Thanks!

I believe that the F# is the ratio of the lens diameter to the focal length which could be used to calculate a FOV. For instance a 3 inch lens with a 12" focal length would be a F4.0 etc ... . Using trigonometry the arctan(F#) is the FOV.

I have this lense from Sciplus.com:
69045 PROJ. LENS
FOCAL LENGTH SPEED BARREL DIA. BARREL LENGTH COMMENTS
5" F:3.5 50mm 52mm Anastigmat

So i assume i'm getting a barrel affect and am not getting the wholw 5" screen?! . . . . .

Anyone know of a good 4" foal length lense for this setup?

I guess i should've asked: does anyone know what diameter and what length barrel would work for this setup that needs a 4" focal length?
This is from surplusshed.com, but not sure if it's gona work:
L2190D---ACHROMAT OBJECTIVE 36MM DIA BY 100MM FL, CTD
Thanks!

Or this:
L3294---4-1/8" DIA NEC TV PROJECTION LENS

There must be someone out there who knows which lense i should use?!?!? OK, i'm feeling lonely here . . .if only my projector was done to keep me company with a good movie . . .sniff . . .sniff . . LOL!

what a whiner ;-).... anyway in my psone I'm using a lens from surplus shed, the kowa 5.4" FL copy lens(just search for "copy lens" at the shed..... was 10$ including shipping...works well.... well, I have other issues with my pj, but the lens is good..... why 4" ? throw length? my should do a 60" diagonal at around 5 feet from the screen (more or less)

oops...forgot to ask what fresnels you're using...I am using 2 page magnifiers with a combined FL of about 6" or so.... which is why the 5.4" FL on the copy lens works ok.....

Ya-i found fresnels but for the price; i am just experimenting with page magnifiers right now that have a 4" FL. Theni will get the real deal. I just figured it would keep the box small with the shorter internal distances.

do you have your 2 magnifier sheets facing each other? I have one against the screen and the other in a separate frame a little after the screen. Best way?

hi everyones!
here my problem:before i strip down my lcd monitor it was working great
now that my project is almost over i have plug back all the wires to the electronics panel of my lcd ,i put the power on to check everything the power light light up
but now display on the lcd.how to test if there anything blow on the circuit or the lcd itself.any guess are welcome.thanks

Hello everyone!

I have a question. How much do you have to know about wiring and lenses to put a decent DIYProjector together? And how good/bad is a OHP Beamer? Reading all of this got me quite excited so I really wanna try this out, but I haven't done anything with wiring before...

PS I live in Holland, does Lumenlab ship there to? And how much will it cost me?

You have to either know how to wire up circuits, or know someone that does (there are wiring diagrams on here if you need it). You don't really need to know much about the lenses except that you buy the right ones that will work (people here will help with that). There are comparison shots on here somewhere that show the differences between the OHP and the LumenLab PJ. Some people have had decent success with OHP, but definately not as good as the LumenLab PJ.

Hope that helps.

Does anyone knows AG Neovo Model F-15 or X-15 TFT monitor are easy to strip off???

Dose anyone know how to fix dark corners? Mine are very dark and everything seems to be lined up.

Make sure your fresnels are in proper place. Switch them.

I did but it made things worse.