I felt the need to start a discussion in here...if anyone has any questions or ideas please feel free to post.

Well Im glad you asked.
I have a first surface mirror in the current design. I made a 45degree back and the sides slope in from 13" to about 5" at the top. Compound miter hell actually but its done.
The 45 was a couple degrees off at first and it showed up in a big way. Top of screen was blurry and bottom of screen was focused. I fixed it compensationg inside where the mirror mounts up and corrected the problem. Exact angels and ways of compensating are a must in the new designs.

The folded design (17") caught my eye.
I was wondering what happened to the focus box that enabled the variofocus to become a zoom ?

Instead of a box to vary the length I saw some room on the 3rd mirror (last one before lens)
You could move that in and out to increase or decrease the focal length and you would have to cut an oval slot for the lens to move accordingly with it. Of course a cover plate for the portion of the slot not being used would have to be made.
You might be able to compensate for any errors moving this mirror as well.
Maybe a frame of some sort and 4 machine screw with 4 nutserts to CAREFULLY adjust it
Then drop the lens where it wants to be.

Hows that mirror on the front going to work ?
I tried it a few versions ago and I found it inverted the image but didnt explore it past that. I turned the sled around and put the mirror inside before the lens.
Will it work reasonably if its not a right angle ???

Steve H

Will there be more specific design instructions for the 15 inch folded designs? I am having a hard time deciding on which project to start on, and considering that I have never done anything like this before, I could use all the information that I can get. I like the idea of the smaller enclosure because I live in a small apartment.

Darron

I had the exact same idea and I drew a couple of pics of it in this thread. Folded designs

DeathRay.
It does work that way because ive done it that way.
Move the mirror out away from the fresnel the distance to the lens gets shorter

Closer , longer to lens.
The position it reflects to changes so you have to move your projection lens as well.

P.S I put the wifes mirror in front of my lens to 45 it one more time and its inverted again. Which actually works for me because my pcboards now are on the lamp side of the box. If i switch the sled around again and put the mirror on the front it will be right side up.

Yes, the lens and mirror are connected so that they will move in conjunction with each other.

Yes, this section will eventually become a comprehensive resource.

Brain:

I posed a question about the cost of the proposed fs mirrors, and didn't get a response. Do you have any idea of the ultimate cost of these mirrors for use in a 17" folded pj ?

Depends on the Chinese supply option. I can get the mirror now domestically at about $25 for a 16" x 12" sheet.

With regard to the 17" folded design, what would be the implications of using just one fs mirror and positioning the lens just above the 'e' in Lumenlab on the specimen shown ? Does it impact the focal length in any way ? Or is this the rantings of a neophyte who hasn't fully grasped the fundamentals ?

The projection lens has to be its focal length plus some extra distance away from the object (panel).

Brain,

Have been lurking here and over at DBG and finally took the plunge and bought the guide. I've been collecting parts since June* and found your new vertical 17" widescreen design to be just what I'm looking for.

(*So far I have an SGI 1600SW panel (eBay), LDI-DVI adapter, the LL electronic ballast and USHIO lamp. I'm planning to use the new "Pro" lens kit in the project.)

Since the new lens kit is still some weeks away, I would like to start work on the enclosure (if this makes sense). Are there additional dimensions/details beyond the initial diagram in the other thread?

Hey buckyball, welcome aboard. Which design are you specifically interested in?

The 17" vertical design with a single primary surface mirror (the 3rd one in the other post). This will fit my room better than the horizontally elongated "simple" design.

The 17" vertical design with a single primary surface mirror is also the one that meets my goal of reducing the size. Any possible aversions towards placing it on its side in the horizontal plane ? I'm a little wary that vertically it may present problems in obstructing some of the view. I'm also thinking ahead with regard to the feed cables having to enter the top of the pj while closer to the floor would be more preferable. Again in the horizontal, I would prefer to have the feed cables enter on the right with the lens on the left. Is it simply a matter of flipping ? Can't make a move until after 9/6+, so I might as well ask now or repent at leisure.

Menuball,
Personally, I would not want to do that. I think it would end up as a scaled-up version of the 7" Lilliput design, which has more mirrors (and attendant complexity) and a larger horizontal area footprint than the 17" vertical.

My 2 cents, anyway.

If you're worried about the view obstruction you can turn it over so the lamp's at the bottom and the lens is at top. If you are going to do that I'd use a lightbox or double paned 'gas glass' to control the heat. It can be constructed horizontally as well but the profile into the room would be larger.

buckyball: We can figure out all kinds of stuff for you. I can tell you that the working distance of the big lens is going to be close to 572mm from the panel. The rear fresnel is 220mm. To zoom you'll want a focus box with at least 2" of travel. So if you have your panel measurements you should be able to start building. If you need a mirror let me know.

My main concern from the start has been size. When the folded designs arrived I welcomed them enthusiastically. However, there is, IMO, a distinct advantage to a one fs mirror design as opposed to the three fs mirror design, with the benefits emanating from savings in cost and size. You can't expect better than that. Only problem, I was expecting Brain to respond with his usual terse nod or thumbs down.

I'm curious about the 17'' Widescreen panel

The panel I own is 15'' wide and 9.25'' tall. How could i put it into that design?

Thanks, Brain, we both must have been responding at the same time.

Turning it over vertically would still maintain the same overall height above the floor, would it not ? I was suggesting that I flip it on its side so that it wouldn't encroach into the line of sight. Then orientating it so that the lens would be on the left while any connections would enter from the right which is closest to my satellite/video/power sources. This location more or less dictates where the pj is to be located, especially since any connecting cables are going to be traversing the floor in an already 100% completely finished basement room.

The "lightbox or double paned 'gas glass' to control the heat" is different than anything I've seen mentioned before, no doubt because of the heat rising aspect, which wouldn't be necessary with my "flipped" approach, I take it.

Just build the enclosure around your panel size. The principle is the same regardless of panel size.

with the "light box" or "gas glass" (for a floor standing vertical pj) is this to be enclosed or is it to have a slot in the box at one end and a gap at the other end of the glass so that the cool air is pulled in through the slot, passed bythe two panels of glass then drawn out by the fan
any pictures would be good as they could explain it better as im not to sure how to
build it

There's no reason the cooling design we use now wouldn't work.

In the first design (the folded 15inch) where should the exhaust fan be mounted? would behind the lens work? Also, should there still be a slot cut into the top of the box (diagonally now, I'm assuming)?

thanks

darron

With the 15" design the fan would be located behind the light. A slot method could be used as it is for the current projector.

Sorry to keep bugging you, but I have another question. With the folded 15 inch design, will I still be able to adjust for Keystone? It looks like there wouldn't be much room to tilt the lens with them mounted 45 degrees to the wall.

Also, the degree of angle for where the lens mounts isn't listed, but I assume it is 45 degrees, correct?

And lastly, I have a question about the 1014 Pro Zoom Projection Lens Triplet. I am not sure I understand how the zoom works. The description says that it has to be mounted to a moving lens board. Are there any pictures in the forums that you know of that show how this is done?

thanks again.

Darron

Hi Darron, no bugging..that's what I'm here for

Keystone should be possible. These designs are fresh off the drawing board so it's a little hard to give specifics without further research. The plans will work however, the theory is sound and straightforward.

The lens is at 45º

For the triplet: It is a varifcous lens. If it is mounted on a stationary board it can simply focus at varied throw distances. If we mount the lens to a moving lens board, we can use the board to enlarge or shrink the picture, than focus at that screen size.

Here's the crude 'box in a box' method I used to test the lens:

http://www.lumenlab.com/forums/index.php?s...indpost&p=22929

i have been looking at 17" monitiors that have above average specs and have found 2 that seem to be quite good
one is the benq fp767-12 contrast 500:1, response time 12ms and .264mm pixel pitch
the other is the samsung 172x same specs as above but .294 pixel pitch
online reviews seem to favor the benq for fast action scenes with less tearing of the image. and should give less sceen door because of the closer pitch
ffc issues unknown
has anyone else found any good 17" monitors?
brain, i noticed that you said you can get fs mirrors for 25US ( hoping to build a vert pj) what would the shipping be to australia, because they are hard to find here and are worth more than gold. i can't believe how much we get rippped off over here

It's not so much getting ripped off by the mainstream as Brain obviously utilising his purchasing acumen. As with the fresnels, which can cost many times more than he is charging, his $25 price for the fs mirror is a fraction of what you can pay for a miniscule fs mirror counterpart on the Web.

At first I was somewhat skeptical ( "you only get what you pay for" ), but the proof of the pudding is in the eating, and I don't hear any complaints from fellow lumenites concerning the quality of their components. Maybe the mainstream manufacturers/distributors are directed towards the business end clientele. We've all heard of the $1,600 toilet seats, which none of us would surely buy.

This comment is entirely unpaid and unsolicited.

For a single mirror 406mm x 317mm, I can get it to Oz for (shipping) $25 airmail (slow) or $35 Global Express. You can cut this mirror to whatever size you need.

thanks for that,lets hope it doesn't break on the way over here.

We will pack it accordingly. Shipped several no issues.

Brain,

Isn't light loss going to be an issue with front surface mirrors? Also, doesn't the reflecting surface degrade over time due to oxidation of the silver or aluminium?

I really like the rear projection designs. This is making me rethink my whole home theater concept.

If I was to position the 'vertical design' (lens up) between two hi-back chairs (with the lens say 12" behind the viewers heads) would there be the issue of 'shadowing'?
I'm hoping not 'cause this would work out great for me...especially the smaller foot-print as opposed to the 'horizontal unit'.

Check out SamSung's SyncMaster 712n
Same spec.s as Benq's and retails around $450.
Ebays around $380. or so.
I looked at one of these at a retail site and found it to have a very small and narrow casing (hoping for no FFC issues) and excellent picture quality...
Anyway, my two cents...

ok,

I am just about ready to start ordering parts

I am going to attempt to build the folded 15 inch design. I will probably go with the regular lens (not the zoom) because of expense.

Should I still get the Norpro reflector? and which ballast/bulb should I use?

Also, can I order the 3 fs mirrors needed to build the project from you? If so, how much?

thanks again.

Darron

I don't think you'll have any trouble from oxidation for a long time (decade). Lightloss is a consideration but we can overcome that by gathering more light from the lamp with the new rear optics.

I can get the FS mirror for you in 16" x 12.5" sheets. If you're interested write me

help@lumenlab.com

Why would light loss be an issue, if it is a FS mirror (and therefore no glass to cut the light transmission)? My projector will have to use a FS mirror due to lack of space, to fold the light either before the focusing lens or after it, and I wouldn't like to think it's gonna be a problem.

One mirror is not going to be a problem..

Could the 17inch vertical design be used with a 15 inch monitor too? It looks alot easier to build than the folded 15 inch. Would the dimensions need to change?

thanks again.

Sure could. The box dimensions would be centered around the 15" but the focal length dimensions wouldn't change.

I am building a vertical, one mirror design, how do I orientate the lcd? I could probably figure it out myself but I am lazy and figured that at least a couple of you guys would know off hand. Thanks.

I want to get started on this asap. Is this a finalized design? Where can I get the right mirrors? How do I setup the wiring eeeh. Im doing the 15"

Me too!
I've got most of my parts and more on the way. I changed my design from 'coffee-table' between two Lazy-Boys to a vertical snorkel 17LCD deisgn behind and between the same Lazy-Boys using the new lens and fresnels.
We're ready for more, can't wait.

I can get the FS mirrors. Give me a couple of days I'll have them in the store.

How much are they going to cost? I leave for school saturdayyyyyyyyyyy

Cost right now is $29.99 () for a 12.5" x 16" sheet that you can cut any way you like.

Anyone know the answer to my question above?

Depends on where the mirror is placed but the lcd faces away from the bulb, unlike the orig. design, i am in the proccess of building my second one, this one is used in thr LLRPTV