sorry,I just noticed you have the mirror at 55 degrees,it should say 50 degrees.
if the light path is vertical,90'. then having the mirror at 50'(5' extra),that angle will double when reflected out of the mirrored surface).I did this using a lazer pointer and a mirror,drawing lines on sheets of paper.It helped me understand the rules that apply in this instance.I hope this makes sense,you are 99.9% there!!

OK, lets say ill tilt the fresnel 10 deg (the same as the Triplet and parallel to the red horizontal line from glass to triplet!)

Im thinking you tilted the Triplet in the first place 10 deg. to be able to get your image projected higher at the wall and not exactly centered in your triplet, and because of that you got a trapeze (trapezoid?) and to be able to get a square image you had to tilt the fresnel, but when tilting the fresnel you not only fix the trapezoid problem, you also set different distances between the fresnel and the triplet, thus getting a slightly unfocused image in some points ( top and bottom with center focused i guess).

Now.. if you manage to reduce that keystone angle to 5 deg, do you still get an image projected high enough (in the wall/screen) and then, you'd be right when u said i´t'll geatly reduce the blurry top and bottom (unfocuseness?)


Am i right? or am i crazy?


EDIT!: read your second post, let me make an image so we dont get lost:P


Cheers!

Alejandro!

Heres the promised pic! I think I got it now





Cheers!

Alejandro

Perfect,thats the one!!
The image does not up or down when you move the triplet.Although,I am really glad it has a 10 degree lift or 4:3 ratio images would be onto the floor,as it is,it is perfect.You have done well. Congrats,its alot to take in.took me alot longer to work out.

Great thanks pun15her a LOT for bearing with me all this time

It seems so much easier now when you see it and understand it on 3D first!


Ill be posting final pics later, the model needs a few things ill render tomorrow coz im way to sleepy to do em now if anybody need's the .ac file (AC3D) PM me and ill upload it

I think i got all the measurements i need , by the way, those ffc filters SURE do theyre job well, like the pic on paint and then the pic with ffc (fss? something like that) you can REALLY tell the difference in queilty, grat job this is the best plog ive ever participated into! Thaks a lot brainchild!

Thanks again for the support


Cheers!

Alejandro

Comedown_87 What program are you using to make those lovely diagrams? :-d

Hey Pun15er,

What a great setup you have there. You have inspired me, along with many, many other people here on LL, to build one of these beasts. I hope it would be acceptable to mimic your design?

I have a couple of questions for you if you don't mind taking a minute to respond:

I was wondering why you had not used tempered glass that I see in so many other pj's?

Can you take some closeup pictures of the circuit board mount near the top of your pj?

Thank you for your time in explaining everything, you truly are a supurb craftsman.

Hi,ScreenScraper.
Thankyou very much for your kind words!
I will go and have a look for a pic of the circuit mount,no probs.
I do have a sheet of tempered glass,the rear fres sits on top of it to shiels it from the heat of the bulb.I was half expecting it to warp,but,so far,no problem!
Please take what you need from the plog and ask anything you want,I am only too happy to help!
Oh,and good luck!

Try these for size,ScreenScraper.
Hope they help:

Programs are: Invis AC3D --> For all de designing and modelling. POVray --> For all the 3D rendering and simulations (video!) although i dont really know how to use the video thingie

And, pun15her is that a new part for designing ?
If so, wats that? to hold the LCD circuits? Thanx! What LCD did u use?

Cheers!


Alejandro!

Sorry Alejandro,it is attached to the lcd carrier,for the benq 567s ver2 lcd.It was incorporated in the design a while back.Being a rather large plog,it may have been edited out,I am not sure.But it was in the box at build time.It means a cut out on the front side fres holder to lets the circuit board sit on the board.
SORRY!!!!
Standard motherboard standoff's are used to secure the circuit in place.Works a treat!

pun15her,

At this stage I am thinking of basing my PJ design roughly on the 15" vertical and your design, so I have a few questions regarding your fres and lcd mounts. The threaded bolt idea looks like a good one, is the frame fairly ridgid?

Are you losing about 5-8mm of the lens all the way round due to the wooden angle mounts? Is this a concern?

Another thought does your LCD have a blank border around its edges? Since you wouldn't want to lose any of the LCD precious resolution?

Are you using a piece of glass to stop the fres' from bowing downwards?

Sorry for all the questions, but I'd like to get all my ducks in a line, before I begin..

Thanks!

Hi,smejworth.
The frames on their own are a little fragile,but I used "no more nails"glue,something like "gorilla glue" may be a better option,but once assembled,the whole "image bank" is pretty sturdy.I havn't had any problems with it.
The lcd fits inside it's origional metal surround,which inturn sits in the wooden frame.therefore none of the viewable part of the lcd is cut off.As the fres holders are the same size,the small part of the fresnel that is cut off,would not affect the lcd in any way.I had 2x pieces of glass cut,1 for each fres,but have found that I only need one for the rear fres,the lenses are reasonably rigid.
Hope this helps!

Pun15her,

Did you get your computer fixed ok?


just curious

FS

FS,Thanks very much for your help.
Got hold of a bart pe disk and ran a couple of checks.
Found some malware,and a wierd "thing" that was affecting auto updates somehow?????
Wierd,cos I have avg,and adwatch monitoring,I am also sitting behind a router with built in firewall,all updating on a daily basis.
Ran a chkdisk and found a couple of chunks of corrupted data,some harmless,but one chunk seems to have been part of the administrator login.
I do have a ghost backup,but it is a month old.Not sure whether to re install windows over the top or not.May do when I get a spare hour or two!!!(not before taking a backup,though!)
Thanks again for your help.

Couple of pics of some very low res music videos.(Where oh where is my £&$("&£^ DVD drive!)

My daughter and her favourate video!


A nice scene from a gorillaz video


And the projector at the time of photographs!

5.30pm,reasonably bright,4x 50w low voltage downlighters,in kitchen area,you can see pj in foreground.
I was pretty impressed.

That looks great for that much ambient light! The Gorrilaz video shows some of the "dark corner" phenomenon that we see so much of, but I'd be willing to bet that it's the camera exaggerating the effect. The lighing and contrast looks awesome. can't wait to see DVD results. (And I know I'm not the only one!)

Cheers Supra,I appreciate the comments.
............................YAY!!! You will never guess what arrived on my doorstep thismorning...........One shiny new dvd drive!!
Going to go and have a play now!
Will hopefully post a bit later!
Cheers.

Pictures...Pictures...Pictures....

Hi people, love reading your threads. Hopefully soon I'll be able to start on my own PJ, but I need to study up a bit more. I have a question about the faded corners. Is that because the circular shape of the back reflector thats causing that? Is there a reason the reflector needs to be a round shape? Does that reflect better then having the whole backside covered in some find of reflective surface?

It will have to wait till kiddies are in bed I'm afraid!
But expect LOT'S a little later on.

What's the height of your finished box?

What's the height of your finished box?

640mm(with 10mm felt feet on the bottom for sliding on my wood floor)

Thanks!

The reflector needs to be a round shape, and that isn't what's causing the problem.

The problem is caused by the nature of the light. Light radiated from a point decreases in intensity proportional to the square fo the distance from its source. The corners of the fresnel/LCD are further away from the light than the center is, so the center gets more intense light than the corners do.

While you view it, this difference can be all but invisible. But the camera doesn't work the same way your eyes do. The camera has to take an exposure over time. The longer the exposure, the greater the apparent difference. Say the corner is getting 95% of the light that the center is. (It's actually less, but this will illustrate the dramatic difference that the camera exposure time makes.) So in 10ms (your eye's approximate response time) you get a 5% difference. In 100ms that 5% has compounded 10 times to make for a difference of 40.1% (0.95 ^ 10 = 0.5987) Where the 5% will only be noticable when you are really scrutinising hte picture, a 100ms timed exposure will result in a brightness change that is really apparent. This is why the camera can make good, even lighting look bad.

<--- EDIT: COOL, got 50 posts i am now, obsessive compulsive


Those are good news , cant wait to see DVD results pun15her!

By the way, got a few questions for you, hope im not asking already asked questions !

Where did you get that reflector?

How much does the projector weight?

Was the Benq an easy strip?

Does the lower fresnel get too hot? Do you use both your PCAC's at full speed and are they loud?

Did you use Lexan or Tampered glass?



And a question in general for anybody:

Where can i get a good temp sensor?

Could only find this one: http://www.gemplers.com/items/G76995.asp


Cheers!

Alejandro!:D

Hi,Alejandro,how you doin?
Reflector is a sugar bowl made by "Tchibo" It only has brushed interior,took HOURS to get it shiny,I would recomend the napkin holder unless you are massochistic (like me!)
I have no idea how much she waighs!!(I can lift it comfortably).
Benq monitor was an absolute breeze,no probs!
I am using 1xsheet of tempered glass,seems to be fine.
The glass is under the rear fres,so it gets a little warm,yeah!(nothing that has me worried though).
That thermometer looks fine to me.(I used a pc fan controller,run off the pc power supply)
Hope that helps!
Oh,and pcac's are at 50%,so not too loud.I like them!

OK.... First pics are in,and I am so dissapointed with the pics!
I was totally amazed with the projected image,it is truly amazing!
But the pics are crap.I will play later,but here are results.(I was looking at the dark detail on leelu's face,it was perfect on the wall,but is non existent in the pic! )







BTW screen size is 98" diag 16:9.

Right then,back to watching the film.

Got some work to do!!!


FLY CRJ's


MINE!

pun15her,

Did a quick color correction with Photo shop, looks pretty good!

Blimey!
Nice one!!,I need to play with my camera.
Thanks FS,I will take another look at the colour on the image too!

Hey Pun15her.

I know you've been following my PLOG, so you ought to have an idea of what kind of difference the setting on the camera can have. Try adjusting the white balance, and see if there's a way to normalize it for the projector.

I'd also recomment both looking at and photographing a simple pallette with red, green, blue, cyan, yellow and magenta as well as black, white, and gray blocks on it. In my case, the dead giveaway that the camera wasn't behaving was that while in person, the colours looked vivid and distinct, the photos showed that it was difficult to distinguish between green and yellow, as well as cyan and white. Gray had a distinct cyan cast to it, as well, though the white was bright enough to still look white. Correcting the colour balance on the camera make a HUGE difference in the quality of the pictures I was then able to take.

Also, don't forget that the LCD has some colour correction available, as well. Particularly of interest was the white colour temperature setting.

Cheers Supra.
I just didn't have the time to play once the photos were taken,I was so impressed the film,I thought the photos would be ok!

Played with camera settings a bit and here is what I got...



I like this pic.I think it is not too bright,not excessively coloured,but pretty detailed.
Still not a patch on the orgional projected image,but better than the last pic.
I am happy!

WOW,had to take a double take there,Looks EXACTLY like FS's photoshopped pic,I thought I'd posted the wrong pic for a minute!!!!
WIERD!

quote]


That would be because you corrected your white balance, which is all I did.



Good job

FS

Just as an experiment,three pics of the same image...







White balance makes alot of difference,also My camera has an AE Metering setting,point,centre or multi modes,multi obviously measures the light from the entire pic,rather than the central point of the image.
Better and better!!!
FLY CRJ...I am running zoomplayer with ffd show,but until I have another 512mb of ram in my pc,I have had to turn off all of the luma and chroma sharpening,I am just using the upscaling. Otherwise it is too choppy.

Whoa those pics look SO KEWL

I want my projector to look like THAT and project images like thatt

envyy


Cheers!


ALejandro

ALejandro.I have been projecting downloaded stills and video until now,and I have been really pleased with the results,but today,watching dvd's has been a whole new WOW factor!!!!!
Do it!

Looking at your new picture, all I can say is WOW!

The detail is amazing, the dark area to the left on the picture has detail and contrast to spare, (Which your original did not) and there's vibrancy and detail in the hair colour that's not there in the colour corrected picture. This at least gives a hint at what you're actually projecting. And still, I sense that you, like me, look at the picture, then look at the projector, and think "But the real thing is so much BETTER!"

Thanks supra,just happy to get across,(well nearly!)how good this thing really is!
I will try to get some more pics later.

Dude! To quote Keanu Reeves....."whoa...."

Thats VERY Niiicccceeeeee!

Havin fun with setup for dvd?

Cheers Samurai.
The pc setup is going to take weeks! There is so much to play with!!
I will enjoy every minute!
While waiting for my dvd to arrive,I made a box for it to sit in out of scrap ply glued together.

These are the parts of the box ready for glueing...



This is it mid way through sanding...



This is the finished box,waxed and polished...



And another,love the stripes!



Just need some feet to go on the bottom now.

I am so loving this project!!

Careful Man! If you make things like this, the wife will expect fun things from you like jewelry boxes, small tables and eventually....furniture!

You travel a perilous road my friend...

good point Samurai.I might have to let her watch moulin rouge !!!

Just one pic today,from the incredibles.all I had time to do,I'm afraid.



Nice and colourful!!!!

Cheers.

Looks good, but still a bit on the green side.
Have you tried manually setting your white balance yet?


Punisher's pic as shot


Punisher's pic white balanced



Damn I hop Haas gets a box to me soon, I want to build a PJ soon!

FS

Puni5her,

Your image has gotten way, way better. No more green push . I guess the camera settings do make a heck of a lot of difference! Looking at your craftsmanship is truly inspiring - but along with status ... comes responsibility; so help this poor, manual-dexterity- lacking, pj builder!!

I'll start with an easy question:

I'm in the process of painting my box. Birtch ply; sanded everything with 150 grit - lifted the grain with some water, sanded again with 150. Now here's where I went overboard (I think?). I couldnt completely get rid of the "grainish" texture of the wood, so I slathered the whole thing with a thin layer of wood filler! After sanding for hours manually, I think I have pretty much gotten most of the putty off, but I am not sure the surface is completely level. I can still see some thicker areas of putty. Yes - there IS a question comming - how did you get your mdf to look so darn good? I want my pj to look really great but I have absolutely no experience with painting a finish. Will the areas of thicker putty show up as surface undulations? Am I on the right track with this approach?? Help!!! Thanks a bundle!

Eee Gads Man! Are you punishing yourself?