I think the reflector will be the easy part. Finding a lense is likely to prove much more difficult. Unless Brain can get whoever makes the regular lenses to do up one for us.

Hello,
For the design I'm working on, the bulb will be vertical. so the reflector I'm wanting to use may have the flat spot, since I'll cut that out for the modal base.
Problem is to find the hemi-spherical bowl that has a radius of 8" to 8.5".
Looking at the IKEA Blanda, 36cm bowl, I think it may work.

Any thoughts? Might there be someone in the U.K. that could get and ship one for me?

Thoughts & replies appreciated.

I suppose it would, but you are just changing the shape of the box. I honestly have never been a fan of the light folding idea. More work and alignment for very little payoff. It changes the shape and dimensions a bit, but it is far from making a big box into a small box or even a medium/big box. These DIYs are still bulky guys.

I am really thinking strongly about the reflector being part of the outer shell of the rear end. The refector assembly would bolt to the PJ body and would allow fans in the front of the PJ to push and channel air through it then out the base area of the reflector. I sketch this out and it adds 5-10% in length, but using the reflector as the outer shell in the rear end would make it visually much less bulky. I visualize a video CANON! I saw an incredible 5500-6000K crazy CRI 1000w bulb a while ago... I movin up! I want to blast some friggin video!
I am a little leary using a 1000w in a highly effieicient reflector... but we'll see

lol I just figured out why I get these funny feelings reading your posts.. I am getting tech info from the DUDE... his Dudeness... El Duderino!
The rug brought the room together man!

Lets just hope we wont need a condensor... if we are going accurate might as well. I saw em at DIYbuildergroup.com

Letting everyone know that I have XL10 at 13" wide and by the 1/8" incremental length. It occored to me that 12x12 might not work for some and it is wastefull.

Yes, they are still bulky, no question. But the folded design does effectively change the orientation of the box. That is, projecting from the end of the box like (as you so picturesquely put it) a "video cannon" is dramatically different from projecting from the side (placing the box vertically gives a much smaller footprint).

That was the reasoning behind my decision to build folded -- not for a smaller box, but for the vertical rather than horizontal projector.

If, you know, you're not into the whole brevity thing.

Just wanted to comment,

I ordered my Ikea Napkin holders from Joe, and they shipped fast, and everything looks great! Thanks!

This might be plowed ground but here goes...
Since the LCD, Frez, etc are square.... would a square like reflector work better. I've seen the square (rectangle) outdoor halogen lights in a rectangle enclosure...

Just throwing it out there...

Snowman

Rectangular

In order to focus on the arc and not have any odd side-effects, one needs a spherical curvature reflector.

The area of this reflector that's used will be rectangular, and you can safely cut out the area that isn't used.

So yes, in a way. Normal light fixtures have no need to have the light point sourced, it only hurts people's eyes and shortens lamp life, so most likely you can't use a direct light fixture reflector, but cutting your bowl to a rough rectangular shape (best to err on the side of caution here, you do not want to over-cut) would be fine.

I think Brain should publish this thread as a book, and everyone who has posted in it can be named as co-authors...

hey I ordered 2 from ireplica does anyone have any pics of how they are mounting these?

FYI the IKEA reflector is sold out at my local IKEA, thus so am I. They say it is auto-reorder but they have been saying that the last couple times as stock was dwindling. I am going to call Monday to see if I can speed up the restock process.

There are a couple ways you can do it, but that handle is just begging to be bent and have a screw through it.

LOL my ol lady begs for that too, but jeez, we've been together like 8 years, LOL
man I'm glad she doesn't read these forums...

BAH HA HA HA!

I made a mount from 2 pieces of scrap 3/4" MDF, cut to shape. This makes the mount 1.5" thick, which is a bit more than needed, giving about 3/16" (IIRC) clearance between the back of the reflector and the next surface. I cut the handle t 1" and drilled a 3/16" hole through it to use a #8 woodscrew to mount it. (Photos upcoming in my PLOG when I take some pictures...) This ought to allow a bit of flexibility to adjust the bulb to reflector distance to fine-tune the light engine.

Upside: Complete freedom of mounting the reflector.

Downside: Reflector mount is separate from the bulb mount. Though this was not my original intention, actual measurements of the bulb and socket necessitated this method.

I bought that reflector. It's really small and you need to cut a lot out of it to get the arc of the bulb at the center of the sphere. Other than that it's really shiny on the inside and it seems to be a perfect sphere.

http://www.imageimports.com/411.htm

Someone wanna try it? Thought id post it...
Looks round bottom since it has a norpro-like base and it claims it is mirror finished. only about 2-3 bucks too...

Quick Question:?
( puts on bullet proof vest...
I just read through all 1200 posts. ( Oh my head...) and I apologize if this sounds really stupid, because Im sort of dazed after reading all this.
I was wondering if anyone had given any thought to creating an array of say 3x4 puck style lamps, or the P20s ( we use them in small spots) and then eliminating the first fresnel lens?

If I have read this right, the first fresnel lens is designed to take angled light from a point source and turn it into collimated light for passage through the LCD.

Can we do the same light by creating multiple soft focus light sources and keeping their target roughly on the LCD?? Maybe passing through a diffuser before the LCD? I was hoping for cheaper bulbs and less expense on the bulb ballast, maybe even eliminating it altogether.

( Lights cigarette, puts on blindfold, mutters to self "I am not a troll, I just had to ask..."...)

Pros? Cons? What have you been smoking?

What your describing is the way LCD monitors work. We need to MAJORLY boost the amount of light, thus the HID's focused with the fresnel

Okay, now Im lost. I thought the whole point of the fresnel between the LCD and the point source was was to take angled light and straighten it out before transmission through the LCD.
Then the process is reversed on the other side by the other fresnel before going to the triplet.

Am I missing something here? Just trying to understand this a little better...

You are correct samuraijack.

Okay, thanks Dergrin. Thought I was loosing it for a moment.
I realize this is more of a play theory, but it seems to me that the first fresnel lens is either not needed or could be made more efficient by creating more diffuse and wider lightpaths. Im thinking that an array of smaller, bright lights aimed at the fresnel MIGHT be more efficient, or at the least, cheaper.
Now, if Im reading this right, then the fresnel for the LL kit is tuned for the angle of the light coming from the point source, so it probably would not respond well to this treatment. So what would we really be looking at? a polarized sheet in front of a diffuse light array? But I read somewhere that the fresnel lens already uses a polarized path, thus making the sheet unwanted.
So Im thinking a wide array, scaled down slightly to account for the spread of the beams, possibly going through a diffuser then through the LCD. The far side remains the same.

Its probably not very efficient, but Im just curious if it will work.

I'm not familiar with the light sources that you mention but I can think of several reasons why one source is better than several. First, getting an even, seamless distribution of several sources over each section of the LCD could prove quite challenging. Second, usually there will be some, possibly noticeable, variation in the color temperature and intensity of each source just starting out. Over the life of your pj individual sources will fail and have to be replaced with new ones that will most likely have an even greater variance then the sources that have now aged. One source will age over its usable life and the drop in intensity and any change in color temperature will be distributed evenly over the entire image area and thus be less noticeable. Third, you will need to deal with the additional complexity of mounting, aligning and powering several sources. Fourth, the lamps we are using have very high intensity (30,000+ lumens), very long life (20,000 hrs) and are quite cheap ($40 - $60). They have been used by hundreds and possibly thousands of DIY pj builders with good to great results.

These are the reasons that I favor the use of the single HID sources recommended by LumenLab. They may not be obstacles for you. Part of the joy of building your own pj is that you can experiment with the design and for better or worse learn from your experience. I also want to congratulate you for taking the time to traverse the meandering path that threads like this one take. This is the natural course of discovery and you are better for trying to absorb the range of ideas and discussion that leads to the design decisions that others have made. It will stand you on firmer ground when you start making your own pj and encounter the challenges to completion that will arise.

just started to gather parts and was wondering if the size of the reflector matters. I found one at work and started to shine it up a little. I believe it is just about 6" . I was also wondering how reflective it has to be? here are some pics(I hope)

Voxelman
Thanks for the encouragement. I will most likely use a single point source, but I got the idea and wanted to kick it around. I may make one anyway just for the fun of it. Worst comes to worst, I can use it for an overhead for my workbench.

I read through all of joewerbs threads on the light box and it SEEMS like he was onto a good thing. How come more people havent embraced this design?

The "lighbox" was just to acomplish a few things that weren't being addressed by th original design. The original LL design didn't use a reflector, have very efficient cooling, or block light from escaping. I got the ideas from a thread elsewhere on the net from guy using it on a 7" PJ. I was just trying to do everything I could to take it from plain big box with light pouring out to a smaller, more attracive, and more efficient design. People definitely started using reflectors over here right away, but that and the other facets of the "lightbox" can be accomplished in other ways than having a dedicated box. In my last PJ (bakery PJ) there was a modified lightbox as the norpro reflector was too big to make a smaller more efficient design. The lightbox became more a part of the entire projector on the rear end. I just did a little to shape the airflow and block the light. Other creative ways can be used to accomplish the same things.

Couldn't have said it any better.

But, then not evryone has Joe's skills, energy and commitment.

Joe you truely are one of this forum's greatest assets.

Here here!
I think I WILL play around a little and try to take some snaps, maybe a cardboard mockup or two. I have had so much fun just reading through the PLOG's and such. I dont know how succesful I will be, but I can spend Saturdays in the AM playing computer games or working with power tools...

Ahh the smell of coffee and sawdust in the morning!
Thanks guys!

Just ordered it, will let u know if it works or not. Thnx for the link.

Jo, do you have to do any alteration to the IKEA reflector like cutting the ends for fitting it the the S400DD bulb, or the focal lenght is just right.
I do not know where are you located but I saw lots of napkin holders in Richmond, BC.

well i have been looking on www.lnt.com (linens and things) and could not find the scrubby holder anywhere on their site so i went lurking and found the same product from a diffrent source
scrubby holder I just want to know if anyone has done comparisons with any of these reflectors and which one do you think is better

Soare Napkin Ring
Blanda Blank Bowl
Scrubby Holder
Other excluding Norpro

Davehtr: Replace "Blanda" with "Steeltek," the blanda has a flat spot on the bottom and is thus unsuitable, while the steeltek is a polished hemisphere.

Wow those are some REALLY kind words! Thanks so much!
( my big secret is that I am self employed... and spent most of the last 2 years screwing off )

The IKEA napkin reflectors are in stock. Picking some up today. Shipping tomorrow.

Sweet! I cant wait. I am really hoping this will help my image a little with games like halo2 and the dark scenes in movies. Other then that I am pretty happy as it is.

Anyone tryed the elleptical reflector?

I bought that exact scrubby holder from that exact company, best decision I have made so far with my PJ. It is well polished, easy to cut with a dremel (I did it with a cordless one no less, in less than 3 mins.), and is a perfect sphere. Plus I was able to use the stock base because the focal distance was absolutely spot on when glued directly onto the back of the box.

I will have it in a couple days

Will be nice to see if there gona be more ligth output whith out the
extra heat to the lcd.

why would that change the heat?

More light directed through the PJ means more energy to be converted to heat.

I am thinking an IR sheild will be key.

I was thinking about the pyramid and tunnel desing and if it has the same affect.
Whit the elleptical desing it would be easeier to sheild out the heat i think...
Allrigth more ligth means more energy = heat.But mabe it would be posseble
to keep the box at lower temp this way by a special reflector cooling fan and
air ways.And havig the fres and lcd cooled sepretly.What do I know?Still think it´s
worth a try.

Is there some optimal bulb to reflector size for this setup?

Jim55,

I tried the light tunnel idea. The problem with that is that any off axis light ends up being absorbed in the box and does not increase the brightness on the wall screen. Only on-axis light makes it through the triplett. Off-axis light simply raises the temperature of the lcd. In my setup the lcd temperature raised an additional 20 F with the light tunnel, but the brightness did not increase at all.

I ended up painting my light tunnel black.

Yes thats what I ment.I was hoping 2things.First,more ligth(and theoretical there will be).Second,no heat.I think that what you do whith a pyramid i to consentrate
heat to the tempered glass whitch heat the fres and the lcd.The offax ligth will produce heat but no that much.And if the elleptical is done and placed rigth there won´t be any offax ligth.And all of this could be bullshit to sence I havent tested
it yet.But I like a differen approach to things and the norpro idea seam to leak
a lot of ligth.

Yep I might pick one of those up from linens n things, I saw the EXACT same one there for like $9.

Do i take the edge off of the ikea? i just got them and there is a little almost like a lip do i cut that off with a dremel or leave it the way it is? I have never used a reflector so I am really new to this.