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I made the bottom 3.1 inches longer than the top to provide space of the ballast. I have a magnetic potted ballast which is quite heavy and would not work well with the pun15sher "bulge" design. The 3.1" give me about an 8 deg triplet tilt, in combination with mirror adjustments, this should raise my image about 18" further off the floor. At least that was the theory.

I was expecting some amount of possible screen tilt, but to me it is tilted the wrong way. I was expecting to have to move the bottom away from the projector, not closer.

Given the reasonable focus (not awesome) focus with the screen tilt, I set about adjusting the LCD and fresnel to mimic the screen tilt in the projector and then I could have a straight drop screen. I got it better, but I had to make some pretty odd and large modifications to the position of the LCD. Eventually I got a center column mostly in focus but then the sides were out. And that is how I left it before retiring for the night.

It seems that the depth of field is very narrow and several inches of screen to projector distance can take things ouf of focus quickly. There must be something about the relative distance between the principles which can adjust it and have things be more forgiving. I have the feeling now that if I breathe on things, the will get out of wack. My 2.5" of triplet focus doesn't seem to give me much room to wiggle.

I was unable to replicate this, but I thought for sure one time that I was able to bring one side into sharp but dark focus when I put my hand partally in front of the triplet. I thought I had a clue to the problem and settled down to play with this new idea and it wouldn't do it again. If this were the case, I would imagine that the problem would be because of stray reflections and alternate light paths, but my uppper box is quite black. The bottom does have some AL foil, but the two should be mostly sealed from each other.

I also removed the second piece of lexan and was surprised at how noticable it was, while removing it the side with the lexan and the side without it were noticably different. The side with the extra lexan was darker.

Right now things are royally out of initial adjustment, with the LCD not just tilted top to bottom but side to side. So I think I will have to start from scratch.

Can anyone point me to some theory threads which discuss in detail the effects of the relative positions of the fresnels, LCD, mirror, triplet and screen? I need to learn more of the theory and see if I can apply it, because the pragmatic method of "move till it looks good and then move the next section until it looks good" is not working.

rearden

I am slowly wading through:
http://www.lumenlab.com/forums/index.php?s...opic=7809&st=40

and it appears that what mikau was experiencing is what I am dealing with. I mayjust have to punt and simply go with a tilted screen. It wasn't very noticable in a dark room and my eyes didn't hurt afterwards because things were out of focus.

If anyone has any other threads I should read, please post them.

rearden

Another thing I need to check, is to make sure the angle between the triplet, mirror and LCD is appropriate. I have an 8deg tilt to the triplet, so the mirror needs to be angled to reflect that.

So my current plan is to measure that angle, set that up static, measure the lcd, fresnel, triplet distances and set up standard. Add some reasonable amount of keystoning and then tilt the screen until things come into total focus.
rearden

I went back last night and remeasured and reset up my measurements. I have some keystoning of about a 2cm difference at the front (bottom of the image) for the field fresnel. I was able to get more focus across the entire image. I was unable to get the left side and the bottom to come into focus at the same time as the top and center. But more interestingly I was unable to get the bottom and side to come into sharp focus at all by moving the triplet or tilting the screen.
What I see happening is that there are 3 seperate images with one of the images being stronger than the other, but they don't seem to merge. This is even when the screendoor effect is pretty defined and the other images I see are not just a general blob, but somewhat defined images. The other images do not seem to be color shifted as in, where the letters are black the other images show up as grey not red, green or blue. The shifting seem to be in a general direction. From the bottom of the image, the lighter images are showing up above the primary image. On the left the lighter images are toward the center. The directions are are in a general upward and rightward direction, but not directly centered.

I know I have some bow in the collector fresnel which I need to get out, so that may be contributing to the issue, but I am assuming that is effecting my light collection more than my focus.

I am going to try to obtain a laser pointer and see if that can help with any of my alignment.

rearden

I took the plunge and hauled the projector into the living room for final adjustments before tracking down some veneer. Frankly, it is huge. And pretty ugly in it's unadored mdf state.
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Here is my 82 inches of lumenlab BO cloth hanging in my living room. I need to trim the upper 2x2 to size. I get about a 100" diag at this distance. Because the projector is to the slightly to the side of the couch I had to angle the screen in order for things to come into better focus. so one side of the screen is 16" closer than the other. I may place the screen one joist further back for a larger image. It is nearly 12 ft to from projector (and viewing location) to screen.
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Here are a few shots of the screen construction. I simply tacked the BO down in a few places and then tacked and stapled a thin piece over the edge. I placed the eyes so that the BO cloth would hang over the edge of the 2x2 (some douglar fir scraps from a previous project) rather than directly from the lathe. (The pic is the back view. On the bottom I did a similar thing (front view). I was surprised at how flat everything hung.
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To roll the screen up I took it down, rolled it up and then rehung it on the hooks. The white screen and the douglas fir matched the colors of the bookshelf and ceiling pretty well and it doesn't stand out as much as I expected. I am still working on WAF, but I think the screen will get a higher WAF than the projector at the moment. I always seem to have some new large project to jam into our small living room (like the 15", 350w sub with an F3 around 20hz... She actually _wanted_ me to buy a screen, which is amazing, the trouble is that the budget doesn't allow it, dang...)

So we watched out first movie, _Nemo_ the kids enjoyed it. I purchased a turtle beach sp/dif usb dongle and it will take the 5.1 output out the usb port and convert it to optical which my receiver will decode. VLC player seems to do this ok. I am currently using VLC player 0.84a. From watching Nemo I have several things to work on:

1. I still think the image is dark. It needs to be completely dark in the room.
2. I need to work on the color. On Nemo the underwater scenes seemed somewhat dingy and brownish, but the above water scenes seemed ok.
3. My primary problem is that the focus just plain refuses to come into sharp focus. I can get it mostly in focus, but never sharply in focus and never completely. The parts which are not in focus and not in focus because I can see seperate images in a specific direction away from the primary image. I will try to take pictures, but I still haven't mastered taking pics of the screen.
4. Heat and air leaks. I have 2 PCAC running at high and the side of the projector is a nice sounding board for the fans and they are much louder in the case than outside of the case. I had to stop up lots of air leaks before I could stop the LCD from getting dark spots.

I screwed down the lower fresnel so the bow was taken out. That didn't seem to help the focus problem much though. The top fresnel may have a slight bow at the top because it is unsupported along the length where the LCD electronics are.

I am frustrated by the "multiple image" focus problem because I haven't been able to solve it, but neither have I been able to theorize a cause. Once the image leaves the LCD, there is one fresnel, one mirror and one triplet. I guess I could have the mirror backwards and not be using the FS, but I am pretty sure that is not the case. The surface which had the blue protection on it is the reflective surface I am using.

I could have my fresnels out of alignment, but if that were the case, it shouldn't be much. What kind of tolerances do the fresnel alignments need? I am pretty sure I am within a couple of mm.

rearden


Click to view attachment

I added the lexan under the field fresnel last night to help remove the bow. I decided that focus was more important that light level. I am thankful I did that. As my wife called today and said that between my 4yr old and her they managed to push the triplet far enough in so that it dropped onto the fresnel/lexan and put an ugly ~8" crack (completly through) the fresnel and a couple of other gashes and scratches in the fresnel. sigh. And I was even making progress on the focus issue. At least it wasn't the LCD The focus rod was not in place yet because I had not settled on the screen distance and things probably needed some more major adjustments.

on a different note and to give my wife credit she allows this beast to stand in the living room.
Click to view attachment

So I am now off to check to see if lumenlab will sell individual fresnels
that stinks, they are out of stock...

Here is in infamous crack and scuff marks.
Moral: keep wife and 4yr old away from projector until adjustments are complete.
Click to view attachment

rearden (impatiently waiting for the fresnels to get off backorder)

that sucks

woohoo! Brainchild and Kellie dug me up field fresnel. Thanks! kudos to Lumenlab!

I received my new fresnel yesterday, but did not get around to cutting it last night.

I went to Ace looking for means to keep my fresnels flat and supported. I found some small brass "U" channels which just about perfectly slid onto the fresnel. They were on clearance and about $1 each, but they are exactly what I needed. The side where the LCD electronics come up, is supported so I think these will help keep it rigid and hopefully allow me to remove the second lexan piece.

rearden

Click to view attachment

I worked on the focus last night, without much sucess. I can get the center to focus really well, a nice colored screendoor. When I see what it could be, it is awesome. But the edges are not in focus at all. It is better than it was, but not good.

Things which I tried last night:
I placed the metal "U" strips around the two long sides of the field fresnel and removed the second lexan. The focus was not what I wanted so I put the lexan back. The second lexan has a noticable detrimental effect on the light output. The whites are dingy in comparison. So if I can get rid of it I want to do so, but not at the cost of focus. Even with the lexan back in things did not improve the way I wanted. So I pulled some sticky rubber plastic strips off of my LCD strip and used them to help hold the fresnel down to the frame. So now there should be no bowing. Still no joy, better though.

I noticed some interesting things:
1. when I blocked some of the light coming out of the triplet, the image got darker, but it also sharpened up somewhat (not entirely).
2. When I ran my fingers in front of the light coming out of the triplet, the entire image on the screen seemed to almost "roll". The image itself moved. I thought that was a bit interesting and could be a clue to my focus problems.

I have been primarily concerned with the upper fresnel and triplet. Does the lower fresnel/lamp/lcd relationship have a significant impact on focus?

The focus on the edges seems to be so far out of wack, it is not that it is just a little bit and I can't think of an area in my projector where things could be so out of line enough to require moving the screen 2+ feet to get a better (but not good) focus compared to something which is just a few feet away on the screen (I have about a 110 diag projection).

I will post pics tomorrow.

rearden

Sigh, Here are the promised infamous pics. I spend a couple hours with a micronometer without much improvement. There must be something fundamental I have missed. The spacing between fresnels and LCD or something. So feel free to call me stuipid and point it out, at this moment I am past caring!

This is on the audience left. It is more like a smear. I can get it more in focus, but not sharp, by moving the screen edge about 2ft toward the projector.
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This is the center, it has a nice screen door. The center column is pretty much in focus.
Click to view attachment


This is the audience right. It has several distinct images in a specific direction. The pic shows how it looks on the screen. I did not move the camera while taking the picture. Maybe there is a singularity in my living room...
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My FS mirror is contact cemented to a 1/2 MDF. There should be no way it could bow. As nearly as I can tell all lenses are sitting flat in their frames and if not the bowing is quite small. The measurements between fresnels and LCD are within a few hundreths of an inch. I am doing about 12mm of keystoning. The top frame and mirror seem to be in correct aspect with each other. But obviously I am missing something, so please point out the obvious to me! I can provide whatever pictures or measurements to those who ask.

rearden

Is your fs mirror at 45 degree angle and are your frensels at 90 degrees, Ck to make sure your LCD is at 90 too. also recheck tour distances to make sure you are in optical alignment and ensure your frensels are on center with eachother and your lcd. All of these things or a combo of these things can cause the issues you are having.

EDIT:
Also your light engine needs to be in alignment. What kind of triplet do you have?

I have the new pro triplet.

The collector fresnel is parallel with the LCD, about 20mm distant. The field fresnel is approximately 40mm (back) and 52mm front, from the LCD. The plane of the fresnels and LCD is parallel with the floor.
The triplet is at an approximately 5deg angle from the verticle. The mirror was adjusted so that the image is correctly displayed on the screen. I have 8ft ceilings. so about 6in from the ceiling and 2ft from the floor. The triplet is about 31in from the floor and the center of the image is approx 53 in from the floor. projector to screen distanct is about 12ft.

It is difficult to check to see if the centers of the fresnels are lined up. I would have to remove the LCD and every time I do I fear it won't survive the transition. I cut both the fresnels with the same method by finding the width necessary, subtracting from teh measured width dividing the differece by 2 and starting the cut that far in. I could have made a mistake, but is not like one fresnel was cut uncentered and the other centered. If they are off, the difference should be in the fractions of an inch. Is that difference enough to cause this problem? Wouldn't that just cause dark sides or something rather than an out of focus image?

The triplet seems to be mostly in the center of the light blob, as in there seems to be only minimal light spillage. Even so when I move the front panel around, effectively moving the triplet up and down, and side to side. The focus problem does not improve, but the image moves in the direction of motion.

I have tried to black out unused portions of the mirror, on the chance that somehow multiple reflections are showing up because I did not cut down my mirror. That didn't seem to do anything.

I have noticed that when I block the light cone before the focus, ie right in front of the triplet. That when I move my fingers across it, the image "rolls" and at some points could even be said to shift. I thought this was a bit odd and didn't know if this is a clue to the problem or a normal phenomena and something I don't understand about the optics.

The lamp should be at the correct location, if not it would be small portions of an inch. But wouldn't this cause dark images instead of out of focus images? I haven't really been concentrating on that part, but on everything past the LCD.

If the reflector was not in the correct location (side to side) would you get two images or just reduced effeciency and hotspots? I am assuming that the problem would be reduced effeciency because of the columinating action of the first fresnel, it would tend to rejct light outside of it's "cone".

Please keep the stuff to check coming, no reasonable idea will be not double checked! I will collect ideas all day and work on them at night.

rearden

Hi,Rearden,just a shot in the dark!!
Is your triplet parallel to the lightpath.
I noticed on mine,that when moving the angle of the mirror,the height of the mirror also needs to be adjusted,and the triplet rotated to stay in alignment...
(Sorry about the drawing!)

I think,from what you have said,your distances/levels are fairly healthy.
And this is the only other thing I can think of!!
Good luck,I really hope you get it sorted soon.
Cheers P

:angry: Well I spent about 4 hours last night and eventually had to swtich to a less frustrating project of debricking a router (that should give you some idea of the frustration level). I tried everything I could think of and now it definately isn't any better and worse than that nothing I moved seemed to have any effect upon it.

The first thing I checked was Pun15her3's recommendation of the tilting of the triplet relative to the mirror.
I got out my angle measure and verified things. The mirror was a few degrees off. It was at 49deg and now it is around 47. the front panel was at 85. I shifted the triplet up about 3/4 of an inch to make up the difference. So it wasn't bad to start with, but tolerances should be tighter now.
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As nearly as I can tell the FS mirror is pointing the right way. I put a piece of tape on the bak side of the mirro and had a small double image when I looked at it from the side.

I put an oven mitt on my hand and moved the lamp around a bit. I also partially covered the reflector with a piece of metal. The only effect I was able to detect was a darkened image and bits of the lamp when I moved it around. It did not do one thing to the focus of the image.

I drug the big fan out and removed the front panel and tried to manually position the triplet where I could get a flat focus. I flipped the triplet around also. I was a bit disturbed to find that I was unable to get the focus I wanted, or near it, for that matter. But that is really hard to do in free space.

I then started fiddling with the fresnels, primarily the second fresnel. For the bottom one, I pushed up on it to change its relationship to the rest of them. It didn't seem to have much of an effect.

Keystoning seemed to adversely affect the flatness of the focus and also seemed to have very little improvedment on the trapezodial image on the screen unless the second fresnel was tilted quite a bit. Now I have removed most of the tilting of the fresnel.

The odd thing was that fairly coarse adjustments to the field fresnel were often required to make changes to the image. IOW the projector didn't seem very sensitive to the position of the fresnels and much more sensitive to the triplet. I picked up the fresnel and laid a piece of plexiglas underneath it so I could somewhat move the fresnel around on the frame. Moving the fresnel around had very limited effect on the image. I moved things 1/2 inch plus in all four directions without an improvement or really much of a reduction in image quality.

I tried tilting the fresnel in large amounts. The image would expand and get worse, but nothing really had the effect I was looking for. I tried bowing the fresnel, picking up a corner, picking up a side . None of those actions resulted in the side coming into focus where I could say, ok hold that position and now lets adjust the other side to bring it in to focus.

I tried flipping the fresnel, putting it in backwards and upside down. No luck. I really can't remove the mirror without doing major modifications to the case and the frames. Gravity is the primary method for holding things in place.

Now I have an image which really is only in focus in the center, top, bottom and sides are out to some extent. The standard is black on white text, not movies. Movies are a lot more forgiving, but I don't want third best!

Click to view attachment

rearden

Here are pics of what I am currently seeing. The sides are mostly smears:

Right side
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Left side
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Center Bottom. Notice the distinct two images. By moving the screen backwards I am able to get the images to converge more closely, but then I run out of space.
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In the double image above, I am able to get one of the images to disappear by placing my hand in front of part of the triplet before the focus. How can light coming out of one part of the triplet through the same point on the LCD give me two different images or come into focus at different distances? What is the physics which would cause it? I was a physics minor in college, but I didn't study optics. I can see some of the project or at least one of the problems, but I don't understand the theory or the practical aspects enough to backtrack my way through the system to find the cause.

As nearly as I can tell the focus plane of the image is curved. Frankly at this moment everything I have done is so jumbled up I can't determine how it is curved. But nothing in my projector is curved! especially not curved enough to cause the image to focus feet away from other focus areas. The only thing which is curved the the reflector and the triplet. I guess you can call the fresnels flat "curved" things.

Is there anything I can check in my triplet? When I look at it everything seems fine. Can anything shake loose in there or become tilted. I haven't tried spinning the triplet yet because it is hard with my focusing mechanism in place.

I did have an accident earlier (see page 3 on the plog) when the triplet got pushed into the projector and cracked the fresnel. I can't see how this could have damaged the triplet, no damage is visible, the fresnel gave, the drop was short and it landed primarily upon the mdf around the triplet, but are their checks I could do, or even take it apart and look? The thing is I was never able to get into sharp focus even before the accident.

I am scouring the forums and not finding much on this issue. It is a bit hard to search because the description is not uniform and thinks like "pro" are not valid search terms.

Any more ideas?

Please?

I shall overcome.

rearden

Sorry to hear that didn't work,Rearden.
I can definateley see 2 separate images on the screen.
And that is not good!
It may be worth checking out the triplet,I think they can be dismantled,although I have never done it!
Other than that,I am afraid the only way foreward,that I can see,would be to make it as simple as possible,by removing the reflector,mirror,all the flashing that I see in the bottom section of your box.Anything that could be causing the second image.Start with the simplest possible setup,then add items and see where the image is going wrong.
Follow a logical step by step construction process.
I know this is probably not what you are wanting to hear,and maybe someone will have a better idea?
But I think you have it all aligned properley,and I dont think that adjustments to any of the lenses will alter the fact that you are projecting 2 separate images onto the screen.

Good luck Rearden.
P

Is the FSM backwards? it is hard to tell on mine which side has the surface on it.

Bet thats it.

You should first remove all that foil and at least paint it black it may act like a seperate light sourse. anything near the lamp that is shinny is a bad idea.

I am wondering if the lenses in your triplet have shifted due to the fall? It really does sound like an alignment problem someplace. I have not even seen a pro lens moreless taken one apart. AZ or Lucky Me if your around could you chime in?

Just saw AZ's post...could be

Are you still getting this light pattern at the triplet??

http://www.lumenlab.com/forums/index.php?a...e=post&id=17496

That would definateley indicate that you are producing 2 separate paths of light from within the pj somewhere.
It also means thhe problem is before hitting the triplet!

OK, I will pull the flashing out or somehow try to black it out. The "flashing" the cheapest AL foil available. Most of the AL foil is spray painted black, especially if it is in the upper portion of the box. The lower portion of the box does have some significant areas of non painted foil. I have not focused there because I was depending upon the fresnel to collominate or reject the light sent to it.

The two image area is most prominant at the bottom, but it is interesting to see the other unfocused areas show up as grey, the more they come into focus I don't see other images coming to join them as much as the contrast being enhanced and the lines becoming darker.

Who has taken one of these apart? Didn't someone take the old pro lens apart? I would rather not, espcially if there is much of a probability that I will not get things back into position. There are not cracks, scratches or visible marks. And when I look through it, everything seems fine, but since the lens distorts things, it is hard to tell.

I will try to simplify. I would like to take the mirror out of the equation, but that would require significant structural changes. I could try a normal mirror and see if I get a difference.

I must admit, I am still using my cracked field fresnel. I did order and recieve another one but then after measuring twice I cracked it also. Sigh. I think that even though the dremel is messy it is the safest way to cut one and I the budget said I must wait before spending yet another $40 on the projector. So the crack is visible on the screen, in fact it exhibits the same double image issue. but there is little difference in the focus from above and below the crack. It is generally off screen for widescreen movies. When I run my fingernail over the fresnel I can feel the crack, but the plane is generally flat.

I am wondering when the doh moment will come and I will realize _that_ is what they meant in step #456 they really mean to put bolt Q into hole X and torque it to #16 Usually in every project there is such a moment. and it can't come too soon.

rearden

No, the was early on in the process. I tested the light image last night before the mirror and at the triplet llocation and do not see the same problem. by forming the image on a sheet of black construction paper. All I got was a nice blob of light with amorphous colors in it. I think I corrected that by putting the AL foil up and stopping the light leaks into upper chamber.

That was a bit odd because I got a nice "GE" image on my ceiling of the garage. It was actually pretty crisp.

rearden

To rule out the fs mirror,could you stretch over abit of your tin foil over a section of the fs mirror and see if the projected image is still "ghosty" on the section with the foil??
P

Here is a full screen image near the end of the night. My camera isn't the best for this (or more likely the user).
You can see the crack and get some idea of how the center is in focus and the outer edges are not.


Click to view attachment

That is a good idea. So use the shinny side of the foil as a FS mirror and see if the image quality changes.
I could then compare it to some other generic mirror I can dig up to see the difference between the three.
rearden

Yep,the image may not be very good,but you should be able to tell whether it affects the twin image problem.
Good luck!

I seriously doubt this could be the case rearden and I'm not sure if the pro would project the same image as the standard when fresnels are mixed but are you sure the fresnels are in the proper places? Meaning collimating at rear and collector up front.

I hosed down all the AL foil in the light box with my clearance ultra flat camo brown (I ran out of black). It didn't seem to have an affect.
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Here is the current back view.
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Another 1 1/2 hours of tweaking without learning much.

I tried the shiny AL foil over the mirror and the results were interesting. No image at all. Evidently a mirror must be very flat to get any kind of image.

I tried spinning the triplet, but that didn't seem to change things much. So I guess I can lower the triplet on the list of suspects.

I remeasured and adjusted the fresnel/LCD relationships but there was no appreciable change.

My next thought is that my slight tilt to the triplet and front are causing some issues. But the minor focus issue is top to bottom, the major is side to side.

Here is a pic taken with the camera placed through the triplet hole. So it is a pic of the LCD directly and outside the "light cone".

Are my issues that most people only look at movies and not excel screens and therefore never see their focus problems?

I can recheck my fresnels, but I did the "coke can test" beforehand and I have a complete, generally lit image across the entire area. All the other pics I have seen of reversed fresnels show very dark, center only images.

rearden

Click to view attachment

Bummer about the tin foil,it would have been nice to rule that out.
My setup is leant back by 10' and I get minor top to bottom focus issues due to keystoning,but left to right is perfect.I have not used any spreadsheets,but I have looked at pages of text,and they are displayed pixel perfect,I don't think you are asking too much of your pj.
I will try and take some shots tonight,to illustrate.

I remember your ge symbol on the ceiling test,it looked great.You may need to get back to that state and build up from there.A systematic piece by piece,build/test,build/test,etc.approach may be the only way to go,as nobody seems to have come accross this particular problem before.
Not sure if you have done this,but have you triple checked the fl of the fresnels,maybe the wrong one got put in the box in the factory???
Just clutching at straws!
Good luck,
Cheers P

do you have a stock triplet?

I don't have the small triplet if that is what you mean. I only have the new pro triplet.

Here is a pic using my current fresnel (right) and the new fresenel (left) I ordered seperately from Lumen lab (and promptly broke). As nearly as I can tell, they are of the same FL. So if a mistake was made, it was made twice.
Click to view attachment

I didn't have too much time to tweak it this weekend (I pulled the carrier out of the front axle of my Bronco2 in an attempt to put in a trutrac, but I wimped out on doing the setup myself But I did lower the field fresnel as was suggested, so the rear is about 24mm and the front about 30mm. I need a bit of keystoning and it would be really hard to go much lower because of the frames. The focus didn't change. It was different but the same general symptoms exist. Center focused, sides way out, top and bottom somewhat out.

rearden

Wow, is this my plog? You were right to point me in this direction, Rearden. I'll definitely keep up with your plog to see if you figure it out. I can't help but laugh reading the last couple pages. Not that it's funny, but its funny that I've been running some of same diagnostic check-up crap the last two weeks. I am frustrated too. It's not fun anymore!!!!!!! I just wanna watch King Kong tonight on my PJ and not my Television!!!!!!!!

We'll just make sure to tell each other once we figure it out. Good luck, homie.

How's it going rearden? While just re-reading your plog I had myself convinced it was the triplet.

"I tried spinning the triplet, but that didn't seem to change things much. So I guess I can lower the triplet on the list of suspects."

". . . didn't seem to change things much"? You ruling out the triplet or not? Just curious. Gotta be some way to test that thing.

I say little prayers every now and then that I don't run afoul of the projector Gods like rearden and arrik.

I have not ruled it out, at this moment nothing is ruled out, just less likely. I spun the triplet but I had to do it while holding it instead of secure inside a panel. It was quite hard to hold all the axes somewhat stable while also spinning the triplet. I didn't see any obvious distortion of the image while spinning. I stopped by HD to look for a mirror, but they were also expensive. I will try and stop by Hobby Lobby or something and see what they have to inexpensive mirrored surfaces to test.

I am skypeable is anyone wants to try a video trouble shooting session sometime. I think with festoon we could even to a multiple participant video conference.

rearden

Just a thought, as I've been reading this forum for only a short time (3 months)... If I remember correctly, one of the members used a laser light to trouble shoot his projector.

I would imagine if you left the bulb off, and then removed the frensel (the one closest to the bulb) and then pointed the laser perpendicular to the LCD screen, you would be able to track the light beam through your projector (seeing its trace as it hits each component). As soon as you see a split in the light beam, you could deduce that the previous component caused the problem.

My first guess is that it is your mirror but you said it is secured it to a board. But just imagine if as you went to secure the mirror, a small piece of hard material fell on the board right before the mirror was positioned upon it; somewhere near the center. That would push the center of the mirror out, curving it. It is simple to double check, simply place a straight edge against the surface of the mirror, such as a short level or a metal ruler.

My second guess is that it is the lens triplet. Although it may be a rare problem, it is statistically possible. You could always purchase a second one, if it turns out that the triplet was bad, I'm sure you can get your money refunded, if the triplet is good, then you should be able to sell the second one at the trading post.

FWIW a plog to check in case you missed it. http://www.lumenlab.com/forums/index.php?s...ndpost&p=102707

I spent some time last night and collected the following data:

When the triplet is further out (further away from the LCD) the bottom is in focus.
When the triplet is in the top is in focus.

When you twist the triplet side to side opposite sides go in and out of focus (they are never in focus simultaneously).

I focused so that the middle of the image is in focus. It is pretty much the center circle is in focus and worse the further away I get from the center.
When I move the screen away the bottom of the image comes more in focus. I can see two images start to converge.
When I move the left of the screen forward, the focus gets better. when I move it back it gets much worse, very smeary. but the lower corner gets worse.
When I move the right side of the screen forward, the focus gets better (never excellent) but then I have a strong trapazoid.
When I move the entire screen forward everything gets a bit better except bottom, it gets worse.

So it appears that to come into focus, the screen would have to be twisted. The sides toward the projector, the bottom away and the center in the same place. And that still would get the corner. And the image would be oddly trapezodial, or actually whatever shape describes all nonparallel sides.

I also put a small mirror and taped it to the FS mirror to see what would happen. I was surprised to see that I had to move the triplet quite a bit further back to get a focus. the new mirror didn't cover the entire light cone. I was afraid that the tape would messup the FS mirror. I could see parts where the image was definately doubled and doubled differently than my pure FS double images.

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rearden

This is taken with the front off, showing the mirror taped to the FZ mirror.
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This is taken through the triplet and shows the position of the new mirror.
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I think I know your plog better than mine after reading through it so many times. I'm gonna say this and you're not going to want to hear it but it's really bugging me that maybe your projector is "simply" misaligned still. I know you've slid and spun things around and done painstaking measurements and never seemed to hit the sweet spot but I suspect it doesn't take much misalignment in a split configuration with keystoning to make things nearly impossible to focus. What a mess. Keep at it rearden. I really hope it comes together for you soon. Maybe just walk away for a week or more and come back at it fresh. Man I wish I could be more help.

dang, you weren't susposed to say that. You were susposed to say, "AhHa!, you didn't hold your tongue the right way in step 47 and the magic fix is to sacrifice three socks to the dryer gods or to change adjustment Q to 22mm."

I will keep at it. It produces images which are mostly watchable for movies in the meantime. I will start from the bottom and move up checking and adjusting. Maybe trash my current focus mechanism and get some drawer sliders. That may keep the triplet more aligned with the front of the projector and hopefully the rest of the system.

rearden

Are you saying you HAVEN'T tried all that yet???!!! At least your sense of humor is still intact. That's a good thing!

Rearden,have you tried removing any keystone on the front fres.
At least that would eliminate any problems on the vertical axis,you would then be able to say for sure that the problem is pureley on the horizontal plane???
From the sounds of it the vertical is behaving as you would expect using keystone,but to be sure that is the case,it may be worth experimenting with,if only to clarify the problem a bit!
You should end up with a more exagerated trapezoid projection,but have uniform focus top to bottom.
Cheers P

rearden,

I've been rereading the "Lumenlab Pro DIY Projector Guide V.2" as I'm getting ready to build my own PJ and I want to be sure I have all my measurments correct.

Anyway, while I was reading through the guide again today, I came across two bits of information, I though might pertain to your image quality problem. I apologize if someone has already mentioned either of these, but I don't believe so.

Firstly, as shown in your picture below, you can see the fresnel rings projected onto the screen. This would indicate that one of your fresnels is too close to the LCD screen. See attached link: http://www.lumenlab.com/protectedwiki/Putting_It_Together
See the 3rd sentence in the second paragraph below the second image on this web page.

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Secondly, I always wondered why everyone only used one lamp to illuminate the PJ, especially when the corners appear to have less light. I originally thought that 2 lamps would be better than one, to help spread out the light. Although this might sound like a good idea, it would be a disasterous mistake. Using two different light sources would cause two seperate images to form on the screen that were shifted slightly away from each other. You can get this same effect, if the lamp is not perfectly centered in the reflector. If the arc is perfectly centered, the light reflected by from the reflector passes back through the arc itself appearing as one single light source. If it is not perfectly centered, then the light misses the arc, but acts as a second light source. The reflected light will then cause a second image to form on the screen, slightly shifted. See the following link: http://www.lumenlab.com/protectedwiki/Reflectors
A simple way to check to see if this is the problem, would be to remove the reflector and see if the double image disappears.

Click to view attachment

I hope this helps,

Cheers,

Fulcrum

Rearden, if you haven't figured out the problem yet can I suggest something that I may have a huanch on?....Can you flip your pro triplet around and see how it looks on projection...better or worst.

From your observations it really looks like your focal planes aren’t parallel. http://www.lumenlab.com/forums/index.php?s...ndpost&p=130982

This is a worry though:

Try tilting your triplet a little bit towards the ground.

DJ