Second build, rebuild...whatever. For those asking on details of my precondensered lightbox. These are my best measurements of the box itself and it's up to you how big you want to make it. My box will be in a vertical, folded pj build and the bulb will be perpendicular to the panel. It's up to you how you want to place it as long as it's perpendicular and not parallel with your panel. Remember my best ANSI lumens of 187 was obtained positioning it this way and using my 5.7% transmissive 15" panel with it's A/G and rear TAC removed and this is with the regular Ushio S400DD bulb and a S51 coil ballast. Also, I'm using the proreflector nestled in a 4" kitchen ladle that has been highly polished with a dremel, polishing wheel and Mother's Billet Polish and notched for the Ushio. The brand of the ladle is Hamilton Beach, perhaps other similar ladles might work. The sides of the ladle helped along with the use of the pro reflector. I mounted the joined reflector's permanent in the middle of the box with springs and screws for forward and back adjustment. The bulb is the only part that slides left and right or up and down for centering on the reflector. I just make the bulb sit on top of the pro reflector.

The precondenser is a 4.5" lens FL of 6.5 from Surplus Shed http://www.surplusshed.com/pages/item/l3381.html I'd suggest you buy at least 2 or more for back up. The frenels I used are both 317mm front and rear. This will still work with LL's standard triplet but I found the Dukane 327 quite better in clarity.

I capped the light box with a 3mm thick aluminum plate. The size of which is 395mm x 252mm and centered a 125mm diameter hole using my jigsaw and a metal cutting blade. At one end I have a square opening of 150mm x 45mm for air supply or air intake. On the other end of the box but behind it is a 120mm Delta Electronics fan, model AFB1212SHE. This pulls about 150 cfm and it is loud! You may go 130 cfm. I tend to muffle the noise when I rebuild. I really suggest you pull a sufficient amount of air across the lens and between the bulb and lens. This is how I was able to get the lens really close to the bulb and if I wanted to..touch it. Right now the flat side of the precondenser is 15mm above the bulb itself or 26mm from the edge of the arc of the bulb. If your using the T15 then play around this area. Now for the mount I used 120mm fan grills that I cut all the inner grills out and left the outer. I found that these grills are not all the same so take note of what you get and how you cut them so as to hold the lens center to the bulb and try to leave the lens unobstructed for the most part by the grill . Also, that electric rod within the bulb...this I placed directly behind the arc. It will project kinda like a brown stain on white screen if off to the side of the arc.

Hope I've given the best details on this. If you need anymore, I'll try to answer them the best I can. And be advise it does take some fine tuning to get the light cone just right on the edges of the 15" panel. If your using a 17" then check my thread on the precondenser tests, Dajyn has some measurements on this and sizes of lens to use. Heck, you might do better than I did since I've been experimenting with a hacked up projector and misaligned lenses.

Happy lumen hunting gents.

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Sim, it might be a good idea to cut the back away from the ladle. That way the pro reflector can do its job a bit better.

DJ

IF the pro reflector has a smaller radius than the ladle, it'd do better nestled inside. Either that, or the ladle is pulled back somewhat so the pro reflector is in the optimum position.

Getting rid of heat.

Sim: I don't understand this part:
"At one end I have a square opening of 150mm x 45mm for air supply or air intake. " I don't see the hole in the pic... do you mean on the front(aluminum) side you hae 2 holes? one for the light output and one somwhere else?

The first image, left of the condenser lens.

Yes, 2 holes the lens opening is the second hole, this allows for the air to pass over and around the lens edges then underneath between it and the bulb. The square/rectangular opening next to it allows for more air to pass over the enitre bulb and not create so much of a back pressure and for a faster flow.

Plans: Drawn on paper, details and measurement not definate. Adjustments will be made as the build progresses.

Work area and radom tools used. Having the right tool for the job determines the outcome and quality of the build.

Found these joiners at Harbor Freight Tools and were very helpfull.

Mock setup with the first lightbox in place along with ribs and triplet mount.

Hey SIM,she looks to be coming on really well.
Very nice work!

Just hope she comes out as nice as yours pun15her. More concerned on quality of projection but your design keeps popping in my head every once an while which means I hope it looks just as good.

Hey Sim,,

keep the scratches to min this time around,, or I will have be inventive all over again,,,

LOL Affirmative!

Some work done. Here are a few mock setups with the new lightbox. She might turn out to be on the heavy side.

Looks great SIM , The weight will be a good thing since its a vertical shooter, it will keep it nice and stable.

I gotta admit,
Im sad to see your hass pj get ranked as a second class citizen.
Its been a huge inspiration for the mini-hass I have in the works.
Your designs are very slick.

The Verty Looks awesome though, fantastic work as always

Thanks brutuz and rest of gents for the words of encouragement including elken .

She will have a permanently set 90 angle triplet, There is no keystoning and her front will have an adjustable footing for raising. I'll be including a tilt screen to compensate. Wheels at rear for easy transportation. Since I'm not keystoning she still will be having a spilt lens setup. Why, you may ask? I tried the unsplit with my precondensed lightbox and for some odd reason the 'white projection' was dirty yellowish. Both fresnels butted up to each was terrible then I tried splitting them by 5mm or more. Still it was not as clean 'whittish' as having them on opposite sides of the LCD. I'm thinking it has to do with the precondenser and the light picking up the yellowing of the lens from heat but when split it is not that evident. Suggestions, anyone?

Also, since my 150 cfm fan is quite loud I'm pointing this part of the lightbox at the front then have the exhaust at the rear. I'll be insulating the box end below but was wondering with what. My old school ways with acoustics were using egg cartons, although, cheap I'd like to use something more professional. Then theres styrofoam, black cushion, fiberglass heat insulation. Any quick, easier and not costly ideas are welcomed.

yoshuaspawn, if I'm not mistaken, yours might be the smallest haas design yet. Hope it turns out the best bud~!

Im thinking it will either be the best,
....or just explode when I turn it on.
None of that middle of the road crap just kidding.
Thanks Simul8r.

I'll take a guess that it is because you are pushing the fresnel limits. The yellow tinge is a good sign of total internal reflection happening to the individual facets of the fresnel. The difference between the split and unsplit would be that with split the front fresnel would be a bit closer to the triplet so it wouldn’t be pushed quite as close to the limit.
This is just a guess though.

DJ

Thanks DAZZ, so by having the unsplit in my old box my triplet is farther away, if I brought the triplet closer then this tinge will more than likely disappear? But then wouldn't I be out of focus?

I've also experienced the yellowish-tint problem before using split fresnels. But I can't recall the exact circumstances that caused it. It might have something to do with your precondenser also...

But I do clearly recall when I was trying to get the 4.5" x 6.5" condenser and similar FL to work with a 220mm fresnel. I would often see a yellowish ring around the perimeter of the bright circle that would not fully illuminate the screen.

I believe now that the yellowish ring may have perhaps been due to total internal reflection inside the lens starting to take place at the far edges of the condenser.

But it's also possible as Dazzla suggests that it might be taking place inside the fresnels as well...

Yep. So there are two possible solutions. Shorter focal triplet or longer focal collector fresnel. I think it’s the front fresnel to triplet mismatch. Say you have a 120” screen then the triplet needs to be about 360mm from the LCD. Add the gap of about 20mm between the LCD and the fresnel and you end up with about 380mm. I think trying to stretch a 317mm fl fresnel out to 380mm is a bit too much. If the collector fresnel is 20mm in front of the lcd for the same size screen(120”) the triplet only needs to be about 361mm in front of the lcd. So the fresnel to triplet distance is now only 341mm, much closer to its designed specs.
You could try to see if there is an improvement in light quality by shifting the triplet closer and moving the arc back. Of coarse the image will be out of focus but good enough to give you an answer to the problem.

Dajyn, I think the effect you saw was chromatic aberration but not caused by TIR. If you look at my avatar, not the shape, you can see that there is a yellowish tinge around the edge. This is simply the blue light refracting closer to the lens than red, leaving the light at the periphery of the cone devoid of blue light. Chromatic aberration is at play with Sim’s set up but TIR is what is causing it to appear. TIR at its extreme reflects all light. Because blue light refracts more than red light the blue will be affected by TIR before the red so the overall light will appear yellow/red.

I can go further into detail inside the fresnel but we better not tie up another of Sim’s threads with techno talk.

DJ


Edit:
I just thought I’d add an interesting observation about chromatic aberration. If you blow some smoke over the cone of light before the triplet you will see that the very edge will have this yellowish tinge. If you blow the smoke over the cone of light after the triplet you should see a blue tinge. The chromic aberration caused by the fresnel gets reversed by the triplet.

" Also, that electric rod within the bulb...this I placed directly behind the arc. It will project kinda like a brown stain on white screen if off to the side of the arc."

There is a spot in the vertical position where the rod should do no harm all light from this direction is wasted light and the rod should be out of view of the condenser and reflector this should be worth a little extra LUX.

I know the drawing is bad. but ther is still the blind spot.

Click to view attachment

I also have seen the yellow around the outside edge of the image mainly on the bottom I was thinking it was a reflection from the particalboard?

I have no problems with this DAZZZ, matter of fact the more you, Dajyn, Mark, Rym, ArizonaV and Rox post I've been learning quite a bit. The only thing I can do is just cause I'm still trying to decifer and obsorb what I can from your discussions.

So, as Dajyn mention in his experience with condenser lens. This is exactly has he described it. Yellowish on the outside and brighter white on the middle. I do have the 330 fresnel from 3dlens that I'm replacing the 317 field to use with the Dukane 327 triplet. I suppose this will work better in an unsplit then, however, I recalled trying the unsplit without the condenser lens before and I didn't see this yellow tinge. Why do you suppose that is?

Thanks AV, at one time I did try placing this 'rod' to the side but it still seem to have gotten in the way. Your right though, I have thought about this 'extra lumens' that I know I may be missing but I was looking for the even spread more so. Thats why I decided this would be better off behind the arc. I'll try it again in different areas around the arc just to be sure, nonetheless.

Just so I get the facts straight. Which yellowish effect are you getting on the screen; a circle of white light surrounded by a yellow haze or some/all of the screen has a yellow haze?

DJ

SIM - Just curious, which parts and their placement dimensions are you using in your light engine now with your latest build?

that yellowish color sounds kinda weird. maybe its some regular optical effect. like the rainbow

I like the way your build is coming along, my main interest is on the precondenser lense since I will be using one in my 250 watt setup. Origninaly everyone was happy with a 400 without a reflector but its looks like you made the extra effort to get as much light out of you PJ as possible. I'll be sure to ask your advice on my lense placement when I get mines in.

DAZZZ, I'll get a pic up to show. This would be better then describing with words.


Dajyn, with the old box? Same as before, it is still the 4.5"dia x 6.5"fl lens with the 317's and the Dukane 327. The new build will allow me to experiment better with the 5"dia x 12"fl lens with the 330, 220mm fresnels.

It is benj, and definately fustrating since I've been studying that unsplit performs better but I guess I'm not working this properly in my old box. We'll see in the new box and with the help of others.


I blame Supra and Rox for this since they mentioned the average lumens goal of 200. It became a quest since then. There were a few that have reported it but for the life of me I couldn't understand why this average was not easily achievable by others and myself and most builds came dramatically short. I suppose a closer lamp would be the way to achieve this but that center hotspot was not to my taste. Now with the bulb perpendicular to the panel and the use of a precondenser lens at least I brought the vignetting (wow, just used the word) to an acceptable ratio.

have you gotten your lcd to work again(or at the same time as the eballast)?

Negative mikyd, the old haas like box has the coil ballast below in that bottom box. It's a little operation gutten it and desoldering in order to just have the eballast just working alone. But don't worry, I havent forgotten your bulb either. As I said my last measurements were at 243 ANSI in the yellowish side color temperature. How this looks on display is the question but definately your bulb is brighter and I haven't given up on it.

does it look yellowish just on the bulb level or on the projection too? mine is really white, no yellowish at all to my eyes...though my other 400w bulb is a standard 4K bulb which is yellowish anyway, so it might be because you have the ushio... anyway, hope you get your lcd back up and running for some screenies! I'm just now in the process of rebuilding my box, probably won't put the precondenser in yet, plus arizona sent me a couple of reflectors to try out, but I think I'll just build the vertical standard so I can impress the wife for a few days woth the better brightness

On projection, the bulb was bright as white outside the box but thru the fresnels produce the yellow. Hmmm, I had thought going past 6k temp would be towards the yellow side but your 4k shows it. Sigh, more testing I suppose

DAZZZ, Dajyn, here are the pics with the yellow tinge as promised. With both 317's butted up to each other - unsplit - I had the lightbox appoximately 195mm from fresnel to plano side of condenser. The next pic shows the fresnels sandwiching the LCD - split - but the lightbox was moved to 192+mm. I lowered the camera settings so to pick up the image I described. I did notice something though, while positioning the lightbox in the unsplit when closer the tinge began to disappear but of course my cone began to tunnel the projection. I suppose the 5"x12" condenser with the 220 or the 317 rear fresnel in an unsplit will remove this tinge because the lightbox will be closer. I'm also thinking that I'd have to go back with the 5" ladle from the current 4" to cover the larger condenser lens.

I don't think you can go just on temperature, it depends on the spectrum it produces also, how balanced it is.... though the sun is yellow? so a more "natural" light would be more yellow? not sure..... I've only projected for a small amount of time while I rebuild the box(maybe an hour total) and it looks pretty normal.... however, the real test is to play the same thing on a crt and the pj at the same time, using the standard 4k bulb whites looked fine until I played the same thing on the pj and the tv at the same time..... then the yellowish tinge was really noticeable on the 4k..... with any luck I'll have th epj running next week and can compare the new bulb and the crt colors...

Just received my new monitor from Newegg. It's a ViewEra V152. I'm already feeling the fear of disecting it.

I remember that... I'm on my 3rd one and actually looking forward to the fourth! hey, don't forget to take readings before and after the ag stripping(I kind of assume you are going to AG strip .....that would be pretty interesting.... heres to good luck on the transmittance, but at worst it will be the same as you have now....

SIM - 190mm seems really close in, if you are using a 317mm rear fresnel.

Are you still using the 4.5" x 6.5" Surplus Shed condenser? I thought you had that spaced 230mm from fresnel to the flatside of condenser lens - and it was giving you good results.

Thanks for reminding me to take measurements. This would be a good opportunity to find how much transmissiveness before and after A/G removal for this panel.


I thought so too Dajyn, I was wondering if it was when I changed to the Dukane that now the lightbox has to come closer. The sled is loose in the old box so I'll set it back to 230 and see if this works with the Dukane. And yes, still the 4.5"x6.5"

What is the arc to pre-condenser distance still the same? What is the distance to the triplet? What is the screen size?
Sorry for the multiple questions

DJ