First off, let me introduce this by saying that I won't be posting pics of the projector. The carpentry is not something that I'm eager to show off, I was in a hurry...

These are pics from a "slapped together" projector using the recently announced LumenLab Pro lenses. These lenses are a top-notch product. A decent build should easily exceed the quality of these results.

Aside from the results, the throw on this lens is particularly attractive. I'm now able to sit in front of the projector, and comfortably view the entire screen. This was simply impossible with the standard lenses and a 15" panel.

Enough babble, you wanted to see results...

One of my favorite movies from the 80s, Labyrinth. All these pictures came out over-bright, using the same settings, I'd used for pictures with my 15" panel.


Pod racing:


5th Element:



(wow, that's bright!)

Supra what is the distance from the lens to the screen and at that distance what is the size of your pictures.

Brain feel free to answer the question

Lens to screen is 9' Screen is 80" diagonal.

This is also part of the cause of the appatrent overexposure/brightness of the image. I did gain a few lumens (Amazing with that much spillage!) but more importantly, the decrease in image size dramatically brightened up the image. More lumens, less area to spread them out on. I'll have to readjust my camera and try some of those pics again. I also plan on re-taking some of the other pics that I've taken, for head-to-head-to-head comparisons, 15" standard lens, 17" standard lens, 17" pro lens.

I'm sorry that I didn't put this in the fiirst question what was the size of the LCD when you where testing ,I was hoping that the pro lens would let me move my PJ back to 13ft to 15ft to produce a 120ft diagonal picture

Sorry, I should have posted that info as well. It's a 17" LCD. It's also lens shifted by 1", for what that's worth. (I'd thought that could be inferred from my previous post, in the part about comparison...)

120ft...whoa

sorry I meant 120 inches

Here's the result for a 15" panel at 13' using http://lumenlab.com/focal_calc.php

And for a 17" panel at 13', that gets you pretty close to 120" diagonal

19.7 is that the focal lenth between projection lens and the frensal

No, that is the focal length of the Pro Triplet.

500mm/25.4=19.68"

Thanks Brain I can't wait until you start the list, I see someone has already stated a list

how much up did the lens shifting move the screen? and OT... how do you calculate that? with a longer throw you get more movement per inch of lens shifting right?

Lens shift! (Ears prick to attention).
Supra is your set-up split or unsplit?
I wish I had enough money to buy a set to try.

DJ

Come on, show us the projector.

DJ

unsplit. I wanted to ensure that the fresnels weren't inserting artefacts into the focus. In order to properly do lens shift, I may need to change it to use a split configuration.

I did cut the fresnels so that I could put the field fresnel rotated 180 degrees, and the center of the lens would be 1" higher that otherwise, but it produces unacceptable moire patterns in the projection, so I didn't use it.

It's really ugly... Maybe when I have something that I can take more pride in to show as a comparison pic.

I adjusted the camera a bit... These pics are also with some keystone angle on the picture (Not much)






The Matrix

And a couple from Star Wars



(Darth Supra?)

It is a pity you cut them. The moire pattern can be reduced by separating the two fresnels. It would have been a good test to try out the triplet’s fov, next time maybe.

DJ

I had to cut them to get them to fit into the box. Remember, this projector started life as a standard lens project with a 15" LCD. I had to make lots of compromises to get it to accommodate the 17" LCD, let alone the triplet and fresnels.

How much did you have to extend the box? Anyway, this lens can be a major improvement, and the "standard" one is a bit too small for the light source we use, I'm also looking for a bigger lens now.

Regards

What is the focal lenght of the pro fresnel-both rear and front?

Pepe:

The box is now 7.5" longer, plus the triplet sticks out another 3 1/2" or so. The old triplet used to be recessed about 1" into the box, so the triplet mount is approximately 8.5" further from the LCD.

Paul3ct04:

The rear fresnel is 220mm, and the front is 650mm.

hi supra. can you tell me the outer diameter of the lens please? i have a 4" wide focusing sleeve and would love to just pop the pro in there. thanks

Just to be 100% sure, Will the pro lens kit thats going to be available in the LL store be a 500mm FL triplet, 220mm fresnel and a 650mm frensel. The distance between the field lens and the triplet will be 500mm?

Brutz,
Yes, the FL you listed are correct. The *actual* distance from the LCD to the triplet will be something more than 500mm, and will depend on 1) how far your field fresnel is located from the LCD (if using a split fresnel design) and 2) how big of a projection you are trying to make.

If you want an accurate answer to your question (about distance from LCD to triplet), use the focal length calculator II, located here.

Hope this gives you want you want.

gs

Thanks Supra.

I'd like to ask one more question. What is the dimension of the fresnel?

Thanks for the help

Supra, could yuo please take a couple of pictures detailing the corners to better show the focus there. Maybe some text or your desktop start bar. Thanks

My camera doesn't do it justice, it tends to blend the image together. I had taken a real close-up of the "start" button. I'll try again though, I'll give the tripod a go.

The pro fresnels are big. I believe they're in the store now, so you can look it up there. The needed to be cut down to the size that I'm using, which is 13.5" wide by 11.5" tall (The field fresnel is 12.5" tall)

I still can't get a good close-up of the start button. This is the best photo that I have, which still doesn't do it justice. For this size, there should be clearly visible screendoor, and charp delineated edges to the pixels. Apparently my camera cheats in low light conditions.

I dont mean to be a pain in the you know what, but is it anyway you SG or Brain can take some more photos of the pro lens in action. I am going to be purchasing them and I would like to see some results. About twenty images from different movies should satisfy my craving. Just so I know its well worth it. Thankyou

Heh. I was taking pictures, but fiddling with the camera to try to get that "start" button picture drained my batteries, and I forgot the alternates at work.

I've been watching movies for 4 days solid, with occasional breaks for work.

One thing though, with the 15" projector, I spent a lot more time looking at the corners, and trying to adjust to get that "just a bit clearer" -- I haven't been doing that with this lens. In fact, I hadn't even noticed that I was doing that so much before, until now, when I look at the corners and they're so clear...

My camera doesn't do this projector justice. It did okay with the 15", but with this one, it just doesn't capture the clarity and detail that's there.

I'm going to try to tripod mount my 35mm SLR and then scan in the photos, but then it'll have to wait until I get film developed. This is probably the only way that I'm going to get photos that truely do the lens justice.

Thanks. This is getting really huge. I wrote that this big lens could be a real advantage, but now I noticed the price. Guys, the whole stuff would reach the price of low-end commercial projectors

Regards

It may cost that much but its worth far more. The Pro lense will give us the ability to use WSXGA pannels at 19" across. This means projections with the same resolution as super expencive commercial projectors worth $3 grand+.

Yes, with this it does reach the price of a low end commercial. At least until the time comes to replace the lamp...

I could buy a commercial projector for what it would cost to build a pro lens projector. No problem. But then I'd have an 800X600 resolution display. MAYBE 1024X768. Not into the HD arena, for sure.

This gets me 720p. You can't touch that in a commercial unit for what this costs. Probably not even if you included the original purchase price of the tools that I used to build it.

Supraguy,

I have been following this topic with great interest as I am currently testing the 135mm lens from DIYPC. As you may know there has been a lot of controversy on the different DIY forums over this lens. I think this would be a great opportunity to work together on a common goal. Which triplet/fresnel combination gives the DIY community the best image with the longest throw. This is in no way an attempt to discredit one lens combo or another simply to present all of our findings giving everyone in the DIY community the most information possible about the various options available, allowing everyone the chance to build the best projector possible to fit their individual needs. This is a link to the work I have done so far Long Throw Build. Maybe we could devise a set of standards we could both follow and then post the results. Thanks for being the first to test the new pro lens. The initial results look awesome. One quick question could you move your projector to display a 6’X8’ image and let me know the distance from the screen to the triplet?

Sack4000

And in my opinion the big panel projectors look better, more filmic.

A quick question!

could someone do the simple math for me:

at 10' away what is the screen size (LxH, not diagonal)

at 12'?

at 14'?

at 16'?


thanks,

REFLEXX!

PS: Ordered my pro lens kit today. I "joined" on Dec 23, of 2004 and this is the happiest moment I can remember!!!

s4k: Actually, I can't do an 8' by 6' image at the moment, I'd have to rearrange my basement to get the projector back that far, not to mention all the stuff I'd have to move to get a section of wall that big again.

For appearance, there's far more difference in the appearance because of the (In my mind small) increase in resolution than I'd have thought possible. I noticed it at first with the standard lens, and putting in the 17" panel, using 1120*840 resolution. But at the 1280X1024, it's a world of difference. Even though I can see the screendoor when I'm right next to the wall, so I know the focus is sharp, I can't see it AT ALL from my seating position. I used to be able to make out the square pixels from the seat, and the individual red, green, and blue dots close up. Now I have to REALLY look to see the red/green/blue, and I can only see it when I concentrate on a white area.

"PRK001 Pro Lens Kit"

is for 15"..19"

But can i cut the fresnels to fit my 10" (to use smaller box!).. will everything work OK!?.. i supose - it should... but maybe something will go wrong...

thanks.

OK!
Looking good so far.
Thanks Supra.
Just to qualify something I am working on,are we looking at a bulb to triplet distance of ~900mm?
Cheers P

Certainly you could, but that will result in a very long throw indeed. For a 10" screen, the throw with the standard lenses is perfectly adequate. This would yield an even smaller box.

For advancements in DIY, the one and only thing that I wasn't satisfied with with the standard lens 15" build was the throw. True that brightness could have been better, but for what I wanted, it was perfectly adequate.

That doesn't mean that I don't find the new higher resolution better, by any means. I'm very happy to have it. It also doesn't mean that if I could find a way to double the lumen output that I wouldn't do it. Improvements are always welcome.

And I'm perfectly capable of buying a projector. If that brightness was what I really wanted, it would be a whole lot simpler to go buy a unit than this was. While the end result of what you get with a DIY project is still important, it's not the end-all be-all of the project.

Do you think that those people who biught the 15.4" WUXGA panels are going to be unhappy with their 1920X1200 projectors because they're a few lumens down from a commercial unit that they could have bought for the same money? And you could even buy a half decent projector for that money, especially those who are using pro lenses with the high res panels. A nice XGA DLP. Or do you think that they'll be looking at their high res screens and chuckling to themselves? Me, I think I can hear the cackles of glee from here...

The Pro lens serves 2 primary purposes in the DIY projector. First, it allows us a good throw, finally allowing the placement of the projector behind the main seating. This is important, because as I stated above, it was the only thing that I was not completely satisfied with from my 15" build.
Second, and party by virtue of the first thing, it allows the use of higher resolution panels, which are typically larger than the 15" 4:3 panels. So while it does not provide a solution to all of the issues of DIY, it certainly provides SOME of the answers. If the answers that it provides are not worth the extra cost to you, then by all means, stick with the lower cost standard lens. It's still available.

Note: OT posts were moved to This thread.

So am i... enjoyed building and now enjoying the theater...
But i just asked question about cutting fresnel... because i think the standart Triplet-80mm + 10" will not give me long throw...

with 15" + triplet-80 i have distance about 2..2.5m .. but i need more.. ~4m (twice longer)

10" + triplet-80 will produce the same image as 15" aprox ~3m (i need a bit more)

But opticaly Pro-Lens is quite better?
And can i use it with my old fresnels?

thanks

Actually, it's working very well. It's not a lot of lens shift, but it's enough to make the small amount of keystone left to get the screen where I want it easily tolerable. At present the screen is about 2" wider on top than it is on the bottom. I could do with zero keystone, if I wanted to, but I did want the image higher.

The lens shift would provide all of the adjustment that I need, but not all that I want.

Basically, at this point, it's all good.

There was a slight shift in brightness from the top to bottom of the screen, which is caused by the lens shift. I've managed to adjust the fresnels to get rid of that. It's amazing what kind of adaptability that I can find in this projector, that I never even knew I was putting into it.

thanks for the info!

Has any testing been done with a 19" 4:3 LCD panel? Would you expect corner lighting and focus quality close to that of a 17" panel projector?

I deliberately offset the 17" LCD from center to get a good idea of what to expect from a 19" panel. Since I don't have a 19", it was the only way.

Corner focus on a 19" is still excellent.