i have that nokia test program, i'll try some widescreen shots and see if i can get some good pics to show you how everything looks. as far as the triplet to get prefect corner to corner, i only have experiance with the standard triplet and i would say the pro from what i've seen. i know others are experimenting with a bunch of other projection lenses too. maybe check out some of the topics in the intelligent video projector design boards for more info on other triplets available.

as promised.. some widescreen test shots.

i set up the display for 1280x720 format using powerstrip so the true panel corners are not showing up. i have a display test program from nokia that will display a variety of test images, its pretty handy.

it can be downloaded here



i can get close-ups of the lower corners pretty easily but i'm far too short to get good shots of the upper corners

lower right:


lower left.. bleeds off my blackout cloth a little bit... on of these days i'll get a real screen...


a pattern to test geometry


closeup of center.

more:

fullscreen text for readability across screen


screen closeup @ angle


right edge of screen a little out of focus.


now the bw negative lower right corner


and lower left corner

more:


test pattern for focus, places these boxes at center and corners of screen.

in blue at center:


lower right:


lower left:


closeup of main screen


from corner of room

lastly.. i mentioned a while back that i had some damage done to my polarizer when i removed the a/g.. it does not photograph very well, but here's the result..

in the lower left corner of the display. shows up as sliver of white no matter what color displayed.


and also along the bottom edge center of the panel ( very small )


finally. dont forget.

Thats great thanks. So the brightness is also perfectly even in 16:9 mode ? Even if i wanted to spend for the Pro triplet I am still leaning towards the standard triplet because I want a big image since I have 1280 x 720 pixels. When I go to the movie theater and analize the width of the screen I find that i am sitting at at the same distance as the width of the screen usually 35 feet.

So are you sitting at 1 x width distance? How is the experience, screendoor?

i think the brightness is more even in widescreen mode because less of the panel is being used.. the top and bottom are masked off.
i'm sitting slightly further away from the screen than the screen's width. my screen width is ~ 98" and my main viewing position (laying on my bed ) is ~ 120" from the screen. i'm far enough away to still have a nice big screen to view but not so close that i have to actually move my head around to clearly see the screen edges. the experiance is fantastic. nothing like having your own personal theater in your bedroom

there is some screendoor when the triplet is perfectly focused, especially after the a/g removal. some ppl will move thier triplet so its slightly out of focus to elimiate the effect but i dont mind it at all. it is not very noticable from my usual watching position anyway and rarely if ever noticable when watching movies and games where there is plenty of motion.

you can see it in this closeup of the test screen

Old school Zelda baby now that's what I'm talkin about. Great test shots btw, you should post some LOTR shots or something.

Your test pics look really great! looks pretty well tweaked to me.
Great Job!

you request, i comply

few more..

Very nice comp, I like the contrast and blending.

Do I spy a dead pixel, or a camera inflection? (awesome screens btw, thanks )

glad u like the white speck at the bottom of the screen is where there is slight damage to the polarizer due to my struggle to remove the a/g. there is also a little bit in the lower left corner as well

So your watching at 1.23:1 ratio. That will work for me also.
Are you using a first surface mirror? what size is needed?

Well luckely you can just take a black marker and mark it off so you can't see it. If your main use for your projector is 16:9 movie watching then you got nothin to worry about.

Comp.....

What did you work on that contributed most to the minor focus issues you have at the corners? I'm going to work on this next. Is it alignment of fresnels, lcd and lens? Is it small focus adjustments with the triplet? Point me in the right direction

Also...... awesome screen shots, excellent job!

yeah, i'm very comfortable with the viewing distance from the screen. though my gf complains a bit while watching 24 on the big screen because the camera tends to be very shaky all the time on that show so it gets a little annoying.

i'm not using any kinda mirror. pj is just a straight shooter

Comp,

Your corner focus looks awesome. I'm going to start working on improving mine. What should I be trying to improve the focus in all 4 corners? Fresnels? LCD? Lens? Alignment?

thanks swill. i think the key is to have all the lenses perfectly aligned. ensure that the fresnels, lcd, and triplet are all perfectly parallel with each other ( minus keystoning of course ) so that the light at each corner is pretty much traveling the same distance from the lcd to the triplet. my focus box is not fixed along tracks or anything so there is some play with me being able to rotate the triplet just a bit relative to the fresnel / LCD

here's my attempt to show what i mean, picture is looking down on top of pj



this allows me to tweak just a little bit to get "good" focus at each corner. with a fixed triplet that can only move forward / backward i think i'd probably have to totally realign the frensels and lcd to really make sure everything is lined up...

comp_atkins.. you have done a great job with your projector! ( i know you must be sick of hearing that by now ) I am in the planning process of making a 17" PJ and you have given me some really neat ideas, i just have a couple of questions..

1. did you cut down your 395mm fresnals? if so, to what size?
2. if its not too much trouble, what are your internal dimensions of your box?

sorry if these questions have been answered b4, but it is really hard to keep track of such a detailed PLOG..

Once again.. great job dude!

..
Valid8oR

thanks! i'll take all the compliments i can get i did have to cut my fresnels down. if i remember i believe i cut them down to ~1 cm larger on each side than the LCD is. i think i tool like 2" off all 4 sides...

i dont know the internal box dimensions off the top of my head but i can easily get them for you tonight.

update val,

my box inside dimensions are 29" long, 15" wide, and 13.5" deep. hope this helps!

thanks for the reply..

it gives me something to base my design on. Maybe i can start building the box soon, but i guess i should wait till i get the panel and lesnes first.. but i hate waiting! :angry: lol

haha i hear ya. waiting for all the parts is like a kid waitng for xmas it probably is a good idea to wait until you get your parts to ensure you box sizes, unless you build in a lot of slack so you're sure your box will not be too small

Acording to your frames is the lcd glass not sitting on top of the ribbon cables of the lcd? So I assume the lcd just rests perfectly in the wood frame like a photo in a picture frame but tightly on all sides. What are you using to sandwitch it so it does not fall out or move around? You have any photos of this?

So your using a 220mm FL Fresnel as your back fresnel? I am now hearing from people that the 220mm fresnel wont get you even lighting on a 17 inch lcd. According to your photos i dont see anything like that? Do you notice any uneveness in lighting on the sides?

the lcd panel does not sit alone in the wood frame, it its enclosed in the plastic and metal frames from the original monitor. the glass panel is sandwiched between the plastic and metal frames, then that assembley is framed by the wood frame. here's a cross section of the frame



the green is the lcd itself, the black is the plastic frame, the grey is the metal frame and the yellow is the wood which encloses it all. the metal frame fits snuggly into the wooden frame so there's no wiggle.


you can see the metal frame enclosing the plastic frame in this pic and the triplet side of the LCD

now just the plastic frame on top of the LCD, again triplet side of LCD showing



this is the bulb side of the LCD sitting on the plastic frame ( metal frame removed )

now the whole frame assembled as seen from bulb side of LCD


hope this helps with your LCD framing. i'd say if there's anything from the original monitor that you can use to hold the LCD try to use it as it just makes it easy to fit the LCD in snuggly

i am using a 220 rear fresnel. i dont notice much in the uneven lighting department but admittedly i'm mostly a widescreen user so i would not notice much corner dimmness. but side to side across the screen in the middle is pretty good.

hmm i wonder then why everyone is complaining about light uneveness for 17 inch lcd?

Ok. my large fresnels just came in the door. One is a 220mm fl the other is a 330mm FL. I was thinking of making the wooden frames for them ready to slide into a light bank setup like yours or pun15ers light bank. It looks like you just siliconed the fresnel to the wood frame on the outside.

Also I really want to be carefull with my fresnels this time so what do you recomend to handle and work with them. Should I use surgical gloves and then can I cover the fresnels with plastic wrap to keep dirt, dust off until in the box?

Also my plan is to use them both behind the lcd but I never considered unsplitting them or leaving say a 10mm space between them. Is this a good idea? Whats the advantage of this? My projection lens is a 360mm process lens.

yup, i used a little silicone glue to hold the fresnels in place in the frames.. its not super-adhesive but holds firmly enough. i'd keep the fresnels covered as much as possible until you're actuallyl installing them just so no extra dust and grime gets on them. its a good idea to keep them wrapped in plastic or something even while cutting. if you use latex gloves while handling them, be sure they are powder free.

i never considered running with unsplit fresnels and i'm unsure of what the advatage of that approach would be. i had read that split ensures that the light passes through the lcd directly perpendicular to the panel where unplit the light is already being bent so does not pass though orthogonally

-cA

hi , sir
I am following your design
I would be using 17'' lcd ,
A standard triplet [ fl= 320mm]

My question is what fresnels would you recommend me to use ?
And if you be so kind, i would aslo like to know dimensions of your box also. Please !

Thank you so much

glad to hear you're joining the diy projector ranks

my external box dimensions are 30" long, 16" wide, and 14.5" high made out of 1/2" MDF giving me interal box dimentions of 29" x 15" x 13.5"

as for the fresnel recommendations, i've only used the standard 220mm / 330mm setup with the standard triplet so i'm afraid i cant offer much knowledge on that subject though there are plenty of brilliant folks around here who can offer sound advice

good luck with your build and dont forget a plog!

Thanks for the reply man .
Actually you were the first one to reply to all of my posts.
The reason i am inclined towards your projector model style is cuz of the quality of the image you are achieving. It's just tremendous !
Now the Question : = As you said you r using 220 mm/ 330 mm ,
but lumenlab is not offering those lenses. They are instead offering :~
1). Dimensions: 431 X 406 X 2mm
Focal Length: 650mm
2). Dimensions: 12 9/16" (319mm) x 9 15/16" (252.4mm) x 2mm
317mm focal length fresnel
Now they have the220mm one, but what should i do about the second one, which of those you would suggest me to use.

Thanks for your valuable response.

i picked up my fresnels @ 3dlens.com they had both the 220fl and 330fl lenses and each were 395mm square. so they did require some cutting down to side to fit in my box. if you are not looking to get them from the ll store i'd suggest you check them out as an alternative.

Comp, that's exactly how my setup works. It wasn't intentional, but it certainly helps.

yup i totally intended originally for it to be fixed and only move forward and back, but when i saw that the focus is actually a little better if i have some tilt.. i decided to let good enough be... for now..

Dracul2006..
Did you get your lenses from 3dlens too? if so, are they the 395mm size (not focal length) with the corners cut off? Even with the corners cut off, is there still plenty of room for them to cover the 17" LCD Panel?

I was thinking about making wooden frames for my lenses too. Instead of Siliconing them in (a little too permanent for my liking) I was gonna try and make a frame in a 'C' shape and slide the lenses in from the top. As long as the gap in the 'C' wasnt too big, there shouldnt be any movement and the fresnels should fit snug.

Comp..
With the threaded rod design, do you have to take the whole setup out of the PJ box to realign the fresnels while tweaking it, or can you reach the nuts at the bottom from inside the box?

Also, (sorry if you have mentioned this b4) but are you using Lexan (X10?) for your Heat/UV shield? If so, where did you get it and how much did it cost?


Thanks heaps Peoples
..
Valid8oR

val,

unfortunatly with my setup, i do need to pull the whole setup out of the box in order to make adjustments. i'm not able to reach the lower nuts without removing the assembly. definatly a drawback with this setup if you need to do lots of tweaking.

here's the frame assembly removed, 4 bolts and unplug the cable from the control board and this thing pops out. it really only takes likes 2 minutes to remove


I do you a piece of Lexan as a heat shield. I picked it up at Home Depot and it was probably like $10 for a panel.

Comp..

What are those vertical strips on either side at the front and the back? is that what hold the assmebly in place in the box? if so, how?

Well, we dont have any Home Depots over here (australia), that i know of anyways.. i guess thats a hardware store kinda thing?
That lexan, i take its a heat shield and UV filter in one.. is this correct? I guess i will have to have a look around and see if i can get it locally... if not.. its glass and uv filter for me

Thanks heaps for your help.. you da man!

yup, those 4 strips are pieces of mdf used to hold the rods and frames in the box. there's a bolt that goes though each strip perpendicularly and attach to the box.

here's the front strips


and you can see the holes for the bolts on the box outside. i painted the bolt heads so they dont stick out as much



lexan xl10 acts as both a heat shield and also blocks UV so it elimates the need for a sheild and a seperate filter.
as for the home depot, yeah, its just a giant chain store hardware store. if you live in any suburb in the US, chances are you're within 15 miles of one

thanks.. I had been wondering for a while how that was held into the box.

How come the threaded rods go so far to the front of the PJ box? Is this needed? And what size rods are you using?

val, nah, there was no need really for the rods to be so long into the front of the box... i had cut them down once from an even longer length and just decided that i could get away with the length they are.. but they definatly could have been a lot shorter... chalk that one up to laziness on my part
the rods are #10-24 sized threaded rods.. i think they were 36" long when i got them from home depot before i cut them down

-cA

Hey, Buddy you have been very kind , thanks very much.
I am following your footprints, and so i need to know few things if you dont mind.
Here are the questions :

Did you use a tempered glass? If yes what size and where did you place it?
Ans:__________________________________________________________

What is the size of your frames [ Internal dimensions and External dimensions ] ?
Ans:_____________________________________________________________

What is the Focal length of both Fresnal lenses ( I think 220 and 330)?
Ans:______________________________________________________________

What is the distance from Bulb to first fresnal? And then distance between each frames?
Then distance from triplet to front fresnal?
Ans:__________________________________________________________________

Are you using the standard triplet?
Ans:_________________________________________________________________

What is the distance from your screen to your projector?
Ans:__________________________________________________________________

Thanks very much

see answers in red i took a stab at the easy ones.. the frame measurements would be more complicated to get as i'd have to take my assembly apart to measure the frames...

Everything looks very nice- especially since you aren't using the pro lense.

All I want to add - is that your link is incorrect for the ballast.

It's actually http://www.hidirect.com - you put an extra d.

good catch i put it there on purpose as a test....

Where can I find/download the test pattern you used in the picture above?

Test pattern are over at http://www.diypro.net/bbs/zboard.php?id=wo...hot&no=3901


Bill