Hello to everyone at Lumenlab,

It’s been awhile since I’ve posted anything on the forum but it doesn’t mean I haven’t been busy building projectors. In fact, quite the opposite I have been spending most of my free time working on new designs and designing my home theater. The problem I kept having with the original LL projector was that distance from the screen was too close. My ceiling is only 6’-8” so the biggest image I can project is 6’ X 8’ at 8’-11’ from the triplet lens to the screen. So, I began the hunt for a lens combination that will give me greater throw. Please don’t get me wrong the original LL projector is totally awesome and my family has enjoyed many hours watching movies with it. However, for my application I need to be back as far as possible from the screen. I am including a link to my first build Sack4000 Projection Project so you can compare this build with my first. As you can see I have decided to ceiling mount the projector causing our old friend keystone correction. We all know that the closer to the screen the projector is the greater the amount of correction you need thus causing you to tilt the field lens so much that it becomes difficult to get everything to focus perfectly. Hens forth the reason for moving it back as far as possible.
The image below is from my first build.

With all that being said,

Here we go.
I have spent way too many hours reading DIY projection forms DIY Audio DIY Projection Company and of course Lumenlab trying to resolve this issue as well as improve on an already great design. After much reading I decided to take Rox’s challenge and try to make the DIYPC 135mm triplet work. Rox has been quoted as saying that this lens will not work with 15” LCDs let alone 17” and since the new Pro lens from Brian hadn’t come in yet (I see that it has arrived and is being tested) I ordered 1 from Allen at DIYPC as well as a 550mm fresnel from 3dlens.com (both we great to deal with). Now we must keep in mind Rox’s claim was based on a 330mm field fresnel not the 550mm from 3dlens but I haven’t seen any posts showing this combination. (If there are please send me the links).
I disassembled my latest LL projector (for parts) and constructed a quickie ¾” plywood test box (please keep in mind this box is only for testing and not a final projector design). I installed my lenses, bulb and ballast, fan etc. For testing purposes I am using a transparency sheet that I printed a modified screen image of my control panel (seems to be a good test for focusing).
You must forgive the lousy image but my printer did a horrible job of printing on clear plastic.

This is a shot of the test box.

Screen Shot

A few things to keep in mind

The below image was taken with a Sony Cyber shot camera on automatic with all the fluorescent lights on in the shop. The image is being projected from 12’ on to a very beat up gloss white wall in my shop. I attached the crappy transparency to a piece of glass with tape and suspended it with paper clips and coat hanger wire from the sides of the box. You can see a black square around the transparency. This was drawn onto the glass to represent the actual viewing size of a 15” LCD.
You can see the image is very clear and fairly evenly lit. (Not bad for a first test).
The image seems brighter in the center but it's the glare from the gloss white wall.

Up Close

This image is with the lights off (The image is 6' X 8' to the black edge). what seems out of focus it just the crappy job my printer did. I found out the transparency I used is for laser jet printers not bubble jet like mine. This might explain why the ink runs so bad. “ya think”

Why?

Now why would I rush to post images that aren’t perfect and require explanations?
“Know one really knows”.
I guess I wanted to see if this lens combination really worked or not and if it was worth building a proper enclosure for it. Based on what I have seen so far I am going to build a real box for it install an LCD and continue testing. As soon as the new Pro lenses are available I plan on trying one of them as well. I’ll keep you posted.

Even Closer

This is a shot of the upper left corner.

Does your enclosure need to be longer due to this lens combination?
Or can you use these lenses with a current enclosure, say a haas box?



Tx
FS

The 135mm Lens

This is a quick shot of the lens and focus housing.

Fastscirocco,

The box is indeed longer. The test box is 38" long including the lens housing. However the finished box will be slightly shorter. I wanted too make sure it would be long enough for testing several lens combos. The rear Fresnel is aprox. 195mm from the center of the bulb arc and the feild fresnel is aprox. 450mm from the 135mm triplet's 1st lens

Awesome job, can't wait to see actual results. I'm current at the point with my pj where I gettign ready to mount the triplet and I'm findind it very disappointing how close the pj has to be to the screen. I used the focal length calculator but either I made a mistake or it was just wayoff. Keep up the good work!

I'm assuming this test was with unsplit fresnels, can you see if it would work in a split design? That's the same fresnel/triplet combo I plan to use, but would really like some keystone correction.

Redd38

The Fresnels are split. The rear is the LL 220mm and the front is the 550mm from 3dlens.com. I'm going to my shop tonight and try the LL 330mm for a rear fresnel in place of the 220mm. I'll post results later.

Sack

sack,
did you try the 330/300 combo with this lens ? how did it work ? ... or did you try 330/550 ?

thanks,
gs

Lens Focus/Mount


I’ve done a lot of testing with different lens combinations and found for me the 220mm LL rear fresnel and the 550mm 3dlens front lens work the best. I tried a 330mm LL rear fresnel it worked fine but the enclosure would need to be even longer. I am about to start cutting out a new enclosure. I’ve decided to make the lens holder/ focus mechanism for the 135mm triplet motor driven. (The 135 has no way of mounting) so I used some 0.5” 6061 aluminum and machined a mount that slides on linear bearings and attached a small gear head motor. Works like a dream. Take a look.

Nice craftmans ship and machine work.

WOW.That is a really nifty bit of kit.
Very nice work.Like the compactness of the drive.
I bet that runs smooth as silk!

This is great stuff - thanks for taking the plunge and doing this experimentation. How far are you from the screen when you have your 6'x8' image? IE: What's the throw ratio for this combination of optics?


Thanks,
Phil.

12' from screen side of 135mm triplet to screen

sack4000

I installed the lens mount on the test box yesterday and it worked great (very smooth). I had to mount it on the outside and backwards because the box is too short to install it on the inside.
The final box will need to be 38" long "wow" to install it on the inside. I was reading Supraguy's posts on the new pro lens. looks killer I plan on getting on the ordering list.
So far these are my findings with the 135mm DIYPC lens.
Using a 15" Benq 567 V2 LCD with a LL 220mm rear Fresnel a 550mm 3dlens front fresnel (split) the 135mm DIYPC triplet a Norpro reflector and the Venture lighting 400w Pulse strike bulb. I can project a 6' X 8' image at 12' from the screen (I'm using 6' X 8' because that's the final screen size I will be using). The image is clear (corner to corner) and evenly lit.
I hope this info helps.

sack4000

So you have a 10 ft. diagonal image at a distance of 12 ft? To me that doesn't seem like a radically longer throw than the standard lens' 1:1 ratio - seems you're coming in at 1.2:1. I do NOT mean that as a criticism - I think it's great that you're making the effort to do this experiment and sharing your results!

That big 135mm lens is potentially brighter than the 100mm Pro setup too, and having an intermediate throw ratio that's proven to work is great for the community.

What's the target for the new Pro lens? 1.6:1 or so? I've fallen a bit out of the loop as I've been away for awhile, and you can't search on 3-letter words on the forum.


Your PJ's looking great!
Phil.

Syscrush

Your numbers are correct 10’ diag. image at 12’-6” and you are correct it’s not a huge gain in throw (about 4’) from my previous projectors however. My goal wasn’t to say this lens is better or worse than the original LL triplet or the new LL pro lens in regards to throw but simply to prove that with the right combination of fresnel lenses this lens from DIYPC can perform very well. I am hoping to work with supraguy to determine which lens combo gives the longest possible throw with the clearest picture. Keep one thing in mind the 135mm is almost ½ the cost. You are also correct in that the image is very bright more than the LL pro I can’t say, but way way brighter than the standard lens. supraguy reported 80” diag. @ 9’ I tried mine at 9’ and got 89” diag. Here is the link to the new pro lens tests from supraguy.Preliminary Pro lens results

s4k

I Forgot to post screenies with the LCD. Control Panel at 6’ X 8’ 13’-3” from shop wall.
S4K

Up close

5th Element screen shot.

Some one on the forum made the comment we were “just building dog coffins.” I couldn’t get that out of my head. I went home that night and came up with this design for the enclosure. I’ve dubbed it the “Cat Coffin.” It’s seen here with the old test box acting as an electrical donor. I hope to mount the ballast etc. In a separate enclosure.

S4K

Side shot

Have you measured the arc size at the triplet yet? I think the 135mm triplet has some room to grow.

I have no idea what this means.

After some tweeking on the lenses and practice with my camera things look even better. Heres a shot of the top left corner taken from where I was sitting. It's not perfect but getting better. way better than my first projector. can't wait to get it painted and in my basement.

S4K

What I was asking was how large is the arc image at the back of the triplet. If you place a piece paper at the back you can see an image of the arc. The one advantage of the 135mm triplet is it could accept a larger lamp arc so if you wanted to you could use a higher wattage lamp and the arc would fit in the triplet. You would get a brighter PJ.

Arizonavideo,

I get it now. No I haven't tried that yet but I will. I'll let you know.

Thanks
S4K

Cool! Great results Sack! I'm assembling all the pieces to build a PJ with the same specs using the DIY 135 with 220/550 fresnels so I'll keep watching this space for more updates.

This would mean buying a new lamp of higher wattage and the ballest that goes with it. Then the new lamp will make more heat so another heat sheild may be needed the glass out of the cheep china shop lamps work grest and cost less than $10.00
You would be the first out of 2000 people to make the leap of faith and it will cost about $150 more.
If I'm right the largest arc that will fit in the 135mm triplet is 54mm or so.
550mm/220mm=2.5 mag x 54mm arc=135mm
This one might fit
http://www.venturelighting.com/LampsDataSh...teLux/33940.pdf

Hi,

I was just wondering if you tried this lense with the 330 Fresnel available by LumenLabs. I ask because on the 135mm lense web site is says that the lense will work with a 330 Fresnel so I am wondering how it went and why the 550 lense is better.

Thanks,

Beekeeper.

Looks like you have some pincushion there sack...corners are kinda dim too. This is what has been reported from this lens. People have had luck changing the element spacing in the lens though.

Beekeeper,

Yes I did try the 330mm LL fresnel. It looked terrible the corners were very dark and out of focus. From what I remember from reading Rox’s posts it’s because of the angle of the light from the fres. To the 135mm triplet. The 135 is designed for something like 24 deg. And the 330 fresnel is like 40 deg. Please don’t quote me as I don’t remember the exact numbers. The 550 worked much better but as I have stated it’s still not perfect.

S4K

Brian,

Good to see you stopping by my plog. I’m not sure what pincushion is but if you mean the slight bowing of the image you are correct. My 550mm fres. Is warped and I need to fab a frame to hold it straight it seems to get better when I manually straighten it with my fingers but it’s hard to tell with both hands in there blocking the light. Corners are a little dark but they have gotten better with a little more tweaking but still not perfect. As you can see the shape of Cat Coffin was difficult to make so I made (2) at the same time. My plan is to disassemble my original projector and install all the parts with the pro lens in the second box. However I just realized the new pro lens combo uses a 650mm fresnel and the boxes I fabed are for the 550mm fres. So it appears the second box will be aprox. 4” too short. “Drat.” I finally have the money to order the new lens kit. Will their be any left in the first order or have they all been spoken for?

S4K

OK,

It’s time to attempt to explain the master plan.

When I was in school I worked in my hometown theater taking tickets, selling candy, cleaning and eventually running the movies. It was originally built in 1906 as the McCauley Opera House. “The acoustics were awesome.” In the early 50s it was converted to a theater. Keep in mind that the 50s were the hay days of movie theaters so it was outfitted with the best. Peerless carbon arc projectors, Voice of the Theater sound, Cinema Scope lenses and a true Silver Screen. So I grew up in a petty cool movie environment. In 1997 the theater was torn down. I have always wanted to attempt recreating that movie experience in my home and now with all your help I think it’s possible. I have been working on this for almost 2 years building several projectors (trying to get the best image possible). Building several HTPCs (that gave me a such a headache) building walls, a screen, a sound system etc.

The Plan.

One of the coolest Parts of the theater experience was after the previews the movie would start in wide screen and the curtains would open wider to accommodate the Cinema Scope format. Currently the only way I know of to do this with a DIY projector is to physically move the projector back. Sooooooo I have fabed a 34” trolley that mounts between 3 ceiling joists (16 O/C X 3 = 32 O/C) in my theater room allowing the projector to be mounted to the ceiling (similar to my first ceiling mount) and moved back and forth aprox. 28” when I want to switch from PC desktop to wide screen movies. This means I need to fabricate a new screen. My current LL DIY screen is 6’ X 8’. I only have 6’-7” ceiling clearance in the screen end of the basement due to heat ducting issues. So the new screen will be 6’ X aprox 11’ (need to do more testing for exact size). Now for the hard part. I was going to simply move the PJ back and forth then refocus manually but why not automate the process?
I ordered a 12 channel IR remote control kit and a count down timer from Carl’s electronics, a couple of 12V gear head motors from Jameco and a pile of other misc. parts then spent weeks putting stuff together. I should mention I have never built a circuit board before. But then I have never done most of the things required to a project like this before (it’s like being back in high school again with all the research I’ve had to do). The focusing, keystone correction, projector re-positioning, fan, lamp and LCD on/off are now all done by motor drives and IR remote control. “It all works killer”. In a reply to Brainchild I stated that I have fabricated 2 identical enclosures when the new pro lenses arrive I will install them into the second box and continue testing until I decide which combination looks best that will be the one that will hang in my new theater room. But enough of all this verbal rambling. Here are some pics. To show my progress so far.

Cat Coffin from the top.

Motor Driven triplet Lens and Keystone correction

IR remote relay Kit

IR remote and count down timer Kits finihsed and tested.

I had to learn how to build my own circut boards to mount the relays that control forward and reverse on the focus/Keystone motors and DC distro. What do you know Radio Shack has "you guessed it" a kit for doing just that.

Relay board finished.

The trolley mounts to the ceiling using 3/8” lag bolts and this board mounts over it. The long slot is were the trolley actualy connects to the projector allowing the PJ to hang below it. The motor for moving the projector back and forth will also be mounted in this. When finished this will be a 36” X 16” enclosure with a black plexie glass cover that will hide the trolley, electronics and trolley motor drive. I plan on painting the whole thing black using Ditzlers acrylic urethane base coat clear coat automotive paint (I spent many years as a body man and custom painter). At last something I already know how to do.

It looks great! I know what you mean about the theater experience. We had an old theater in my town and it was the best place in the world. I came THIS CLOSE to putting crushed red velvet on my PJ!

By the way, your avatar is very.....hmmmmmm....distracting....yeah thats it....

Thanks SJ,

Some of my fondest memories are from that place. Dude thats my 100th post. cool.

I remember the best part was the screen that stood on a stage that still had the old oil lamp reflectors lining it and the curtains were as old as the early 40's. The paint in the theater was flat from oxidation, yet it was still vibrant and they used a lot of cool and deep blues accented with red. The second floor was very special. The balcony was were we took our dates ( or they took us...) to make out and watch the movie...in old seats that still had horsehair and worn leather coverings and the scent of stale coke...
Strawberry musk perfume, popcorn and old leather still swirls in my mind when I think of the movies I saw there...and the lovely girls I shared them with...

I salute your recreation and offer any assistance I can...

LONG LIVE THE MOVIES!

SJ

SJ,

I couldn’t have said it better. I mean where else were you going to take your date on Saturday night in a small town. To a movie and then cruisin' main street. I wonder if I can recreate the smell of stale coke, strawberry musk perfume, popcorn and old leather.

S4K

Sure just invite a couple of us LL friends over.

I finished wiring all the control circuits to the projector. I used a 12 pin molex plug to connect them so I can easily unplug one from the other. Everything works perfectly. I took the whole thing home (very unfinished) and began testing with my HTPC and LL blackout cloth screen. Initial results look promising. More testing to do.

S4K