Found a site that has this:

Brand new, for a projection TV, this 4-element lens is in a 6-1/8" long x 5-1/4" dia black steel barrel with #24 threads at both ends and has what looks to be approx 16" to 17" focal length.

This seems similar in specs to the ones people have had good results with out of opaque projectors. I am wondering though what difference there would be with these being a 4 element lens instead of a triplet?

Well I was informed that this lense is basically the same one they have at DIYPJCOM. Even they say it is best for 15" or smaller panels. What makes that the case? Focal length too short/long? The site I got it from (http://www.sciplus.com/) does have them for $30 so it beats DIYPJCO's price by a mile.

This lens is made for a rear projection screen tv. Those have very short focals. I would guess that since it says 4 element lens, that it isn't similar to the diy lens, since that is a triplet. Here is a post on someone who ordered that, they use to post a 12" focal.
http://www.lumenlab.com/forums/index.php?showtopic=11555

I think some people have tried this lens but are not talking. Ask Rox if he has seen it before. I have yet to see any one post a picture and try to make it work. It migh be ok for a 15" lcd but some one who has one need to TALK and say if it can focus on a 15" LCD.

I have the lens and tried it. The FOV is way too small to focus anything more than a 10" diagonal LCD. I have taken the lens apart-it is a TRIPLET - not a 4-element. I actually talked to the procurer for American Science who told me he is unaware of the specs of the lens, leave alone that it is the same lens as at DIY Proj Company?? Where did you get this info?

triplet, somewhere 18" (meassured focal whatever the specs claimed at american science are) 5" aperture, 6,5" long.... this is identical.

It is an expresion here that traduced to english would be like; white and botleled; milk.

Sounds about like I said. They changed their focal and info on the page. This is a lens for rear projection tv's, and has a super short focal length. I remember seeing it before, and the info is different for some reason. I believe it said the focal was like 12" or something.

if you check the photo on the website, you will see it is the wellknown 135triplet. I believe the description has nothing to do with the lens. (Yes, the description maches the fujinon TV projection lens)

So you are gonna take everything from a picture. And Sonic comes on here, and says it is not the same. Hmm, basically calling Sonic a liar are we. There is no way it could possibly be different internals from the same case? Possible these are lenses that were made by the same company, but these are flawed, thus they sell them to a surplus store? I know surplus shed sells stuff that was either flawed or no longer used.

hmmmmm

well, 2" focal (fujinon) and 18" focal (135 triplet) should be easily noticeable diference. Don´t you agree?

Yup, and when Sonic says it only focuses on a 10" screen, that tells me it isn't 18" don't you agree. So probably in the middle, roughly 12" maybe. Maybe what they originally quoted it as.

Blame ME for the confusion and arguments about this lens.

There's a DIYPJCO forum member that has the SciPlus lens AND the DIJPJCO lens.
He told me the lenses look identical and function identical when used in a projector
(he tested them).

I bought one of these several months before I learned this info.

Ok, now I will tell you what I know about these lenses. I have known about them for a long time. I ordered both. Here are the facts. First, they are not identical, although work identical. The internals are different. The lenses, I switched and are pretty close but not exaclty the same, but the weird thing is, is the middle holders are longer on the science surplus. Thus, their are a few differences, but yes, they work basically the same. You can claim very similar, but not exactly the same as a 100% certainty.

I know all of you are sitting there right now, wondering why I have been fighting this. And haven't told anyone. Well, think of what you have just done. Who is going to spend $200 on a pro lens here now, or any lens sold here or there, if you can get one for $30. We have explained how to modify and get a 500+ focal on the this lens, so you now have in essence screwedover the people who have helped you get to where you are. Do you think anyone here would have any of the knowledge that we have, if it wasn't for some of these sites? Do you think that they are run for free? I do know that alan will start ordering his lenses directly from there and lower his price to an equivalent amount, since they are cheaper by far, for roughly the same lens. I believe he is waiting for the current priced inventory to run out. But just think of what this means...

yes, my sensation was that this "source" was hidden somehow... I don´t care if the lenses at DCP are sourced from here... In fact your suggestion that now that this "posible source for same lens" is known and that could change pices at DPC... I don´t see why isn´t it posible that it had always been that source for DPC and he just 4X the price at the store.

Right now the only thing matters to me is WHY is there people with FOV issues whit this family lens and also would like to hear some conlusive replyes from the "true DPC triplet" moded lens owners (only crhist as far as I know, although "some members have reported they have near perfect corner to corner", yes, Im still triyngo to source that info with no luck...)

About your coment "why have you been fighting for it", yea, this is still something that intringues me. I mean I don´t understand why isn´t alan working HARD for those proves, images, member that succeded,... to see the light. Instead, it is you, chirst... the people he rejects the resposibility to showing the performances. And this is after claiming things at store... amazing.

Rox, you read nothing of what i just wrote. This lens is not the same as the DIY lens, infact it is different in many ways. This is not where he ordered these lenses before, and yes, he paid that much more before. And, I have shown and said that I get near perfect corner to corner. Brian can thank you and others for his lenses not selling anymore. That is why I was fighting for this. So you my friend, are a ....

who is brian? (chirst?)

diferent in many ways.... Iam all ears.

you are having near perfect to perfect on a 15"? Two times you said you proved the corner to corner focused image right now, so two times will I ask again for where your proves are.

I don't know, I thought it was Brain/Brian or something that owned this forum. Who ever it is, they can thank you, cuz who is gonna buy a $200 lens for what they can get at $30? Maybe not perfectly equal, but I sure price is a factor with 99% of the people in this world. Otherwise, there wouldn't be a big broohaha about this whole thing.
Here is how you don't listen, except for what you want to. I said, the lenses are different, and the middle holding pieces are different, the case is the same. Secondly, you have seen my post, and I have shown you numerous times. The only reasons these are not showing as clear as they should, is the photo was taken at .5s 100/f , but you can see the corners are clearly readable. Tonight I will take a pic with the 400w, and the corners at a speed like everyone else here does, like 2 seconds for shutter speed. In personal there is no sign of blur, except for the light arc being too long. With the 400w ushio, there was no blur what so over. you spend too much time trying to disprove everything. Edited: next page shows results

yea, that definitelly proves everithing. (sarcasm)

this was 15" true?

Miedos, it is al about HONEST sellers. Yea, I agree that the pro lens DEVELOPED here is more expensive than any other lens. Ever heard about cuality/price ratio... I guess you know why it is more expensive.

As far as I can say, NEVER HAS BEEN PROVED the moded 135 triplet works. BUT the FACT is that 17" near perfect corner to corner focus is being claimed on DPC since 2 months back. Ask crhist why did he unmoded back to the original design the 135triplet. And also, please look for 1 successed menber... (I am tired of asking it with no luck).

the 135 triplet is a GREAT lens. This is a fact because it has some great specs, (nice focal, nice aperture... but the FOV is the only problem. This makes the lens the best choice for small panels. And a compromised lens for a 15" and higher LCDs.

I know there a different bunch on the 135 lenses. maybe some slight modifications on them... but the "far different" lens at american science is toatally compatible with any of them. I believe they all come from the same manufacturers.

If youre watching 16:9 images (which if you arnt, are you F'n crazy? ) i dont see a reason to spend the money for a pro over a Buhl 18" . If perfect focus is your goal save your money entierly and buy an SP5000 infocus.

Heh, I'm not worried about lost business because I know we have the best lenses for the job, not some hack lens from surplus. The Pro Lenses are awesome lenses that work perfectly for HDTV builders. We designed our lenses ourselves (thanks for the help Rox). For those that want to build a projector worth having, the Pro Lenses are what to use.

I don't like the accusatory tone to this thread. We don't tolerate whining and name calling here. Keep it civil or this thread will be closed and posting abilities will be reduced.

I actually stated that, no? Like I said, I would bet that the same company made both, and charged Alan more, so how is that wrong on Alans part. He wasn't overpricing anyone. He sold it for a small amount over what he paid. Either which way, doesn't matter to me, since Brain said he doesn't mind. I also see why this was such a big deal to you now. I guess, since it is in the open, no biggy. I also said those picks were flawed. Wait until tomorrow when I am at my office. I took my pics of the same size projection, with the modded lens that we are talking about. switched to the 400 ushio light, and close ups, so you can see the pixels. That camera was a borrowed, cheap and worthless. My new camera is a 6m pixel panasonic, and I can tell you, that my corners are gonna show you that the picture I am watching is near perfect. I prefer the brightness over the clearness at this point, but since this became such a big deal, I switched my lights out to prove this lens works. Just guess you will have to wait and see. Edited: Here you go, you can go see the corners pictured here, they are clear enough for me, "Quality/price. I don't know about a 19", but I can tell you the 17" wide screen gives equal results, no blurry corners. I built one, yes.

actually, you can´t guarantee me the lenses from Alan where or where not coming from american science... In fact, I don´t care what alan paid for them. The bussinessing is welcome, It is the final buyer who decides to pay the price requested, no matter how much the seller paid for it.

I see you are planing on bussines too. Hope you will have success with it.

You built 17" widescreen... but the photos are from a 15". Will have to wait for the 17" photos I guess. As mikyd said, if you are planing on widescreen images... (that is identical to working with smaller panels) there is no problem with the lens.

Hmmmmmmmmmmmmmmmmmmmmmmmm

It is simple math,, or not,,

I have said it before,, and it looks like I say it again,,,,,,,,,,,,!!!!!!!!

you get what you pay for, nothing more nothing less

A cheap lens is made to a spec,, a plus and minus spec,,, and in this senario, there are three optical elements

A total of six surfaces, with coatings, and also these lens are truly mass produced, almost stamped out so to speak,,, that is why they are so cheap,, the correction is not going to be anywhere within 20% or thereabouts due to the plus and minus tolerances, also the glass used can have allsorts of impurities or varing refractive indexes,,
ergo complicating the final resultant image quality and shaping

Now i have dealt with many lens over many years,, and your basic triplet of any reasonable quality is gonna cost you no less than a figure of around 400 to 1000 dollars USD for a lens that is only 4" diameter, admittedly this is an astronomical lens,, but the lens such as LL pro lens,, needs the same or at least near enough charactristics too, because edge of field is an issue no matter what field your lens is used,,

now to buy a triplet for a commercial PJ is gonna cost you at least a $1000 usd for a PJ,,, that is equiv to the 17" panel and LL Pro lens type of quality image

So the short answer is for the LL Pro lens, even tho I dont have one yet, seems dam good at its price,,,


If anyone doubts what I say go look yourself, at the price of a half decent lens (triplet), is then come back,,

the cheap surplus things are just play toys,, and or rejects,,, not even seconds,,, fourths in the pecking order

so you cant compare,,,

Astigmatism,,, now thats another little curly bit in this whole game too,, I noticed no one hasd even begun to check if they have it with image results,,,, this will show up greatly to edge of field view to,, and often in one direction,,,, a good lens triplet has all optical elements rotated to match for best astig,,,, another little important fact in optics,,

IE a good lens will produce a difraction pattern inside and outsisde focus, also the difraction rings must be even either side of of true focus too,, another erroer in bad optics,,,, hehehhehehe

but one needs to have a single point light source to test these little extremely important image quality facts,,,

all of the above are working, for or against you, depending on the quality of triplet...

I have not just begun businessing, I have owned 3 businesses successfully for a while now. That is why I protect other SMALL business owners from people trying to discredit or disrupt their business. My most disliked thing, is a customer to come in and say he can get it cheaper elsewhere. I tell them go ahead. If you can get it elsewhere, don't come and tell me, just go on about your business. I don't need to hear someone tell me that (example) Walmart has cheaper food than Mom and pops store. That is the deal, there is always gonna be a cheaper or better priced thing out there. Those are just pages I no longer use, that is why I use them to post images. You are right, the images are from a 15", and I can only state that the 17" looks as equal, since the lcd that I stripped for the guy was crap. When he gets his new lcd, he can let me take new pics. As for Christmas that you have been talking about, he just posted his results from this lens on his built proj post and 550/330. Doesn't look like he is unhappy either.
So, in final, from my results shown, Christmas's, and etc. I would say $40 will be a pretty good price for this lens with a clear image to the corners. There are no imperfections like someone says, to the eye. Yeah, maybe for the professional or something, but not for DIYers. Looks like others will start posting results soon too. Guess we can only wait and see.

I am not the best choice espeaking about christ's projector... I would like him to post his final conclusions on the mod thing...

but as far as I can say, he tested both of them and decided going back to the unmoded one. He has very good image yea, that is a fact. But this things are discusable in terms of light evenes (vigneting) and focus habilityes. He said he was going for the pro lens once... I wonder if he finally keeps with the 135 triplet or upgrades to the pro...

Your inputs are welcome crhist.

I can’t recall Rox ever saying the 135mm triplet is as good as the pro, quite the opposite.

Damn, my english must be worse than what I had thought... Why would I say that stupid thing?



(now if somebody asked me what does it work better on a hami, no doubt the 135 triplet is better choice)

No, you said Quality/price I think. "Ever heard about cuality/price ratio"

thus, comparison for price over quality, you make a benefit analysis. Will paying $160-170 more give a person that much more benefit. That is what you said in long form. Right?

no this is not what I was trasmiting.

here is the second try;

As the pro lens is SUPERIOR on specs and that means better quality since it was EXPRESELLY designed for us, it is more expensive. Now the price/quality ratio is just a generic term. Hardly workable for us. I can work out a ratio for both lenses but this is just my personal ratio. Some will agree and some not. But the unquestionble point here is that the pro lens is superior lens. (forgeting the price parameter and only checking specs).

I've never disagreed the Pro lens is better than the other. What I am saying, is the many of the builders are basing projects on price, right? Many people will look at my pictures and Christmas' 17" panel, and say, hmm, is the price or quality that much more beneficial. So you are right, each person will have a different ratio of price over quality.

Well, for me, the facts are simple.

I want a 17" panel. I am not only watching movies, but also using the projector for desktop, games, and other PC duties, where I need to be able to see the whole screen. In some of these instances, the text in the corner of the screen is vital that I am able to read it easily. For that, the pro lens was the only way to go.

It should also be noted that for some of the stuff that I want to watch, 4:3 is necessary, since a lot of the material was 4:3 in the first place. For a movie that was filmed in widescreen, that's great, and I'll take the widescreen version every time. Not all of the stuff I watch was filmed in widescreen though, so I need to be able to properly play 4:3 aspect ratio stuff, and get good focus.

Price is an issue. This is true. However, to me, the cost of an inferior product has always been the cost of the inferior product + the cost of the better product to replace it. Considering that the cost of building a pro lens projector, using all LL components, a brand new 17" LCD, and a "reasonable" budget for the box itself is about $800, a "savings" of $100 or so to come up with a projector that isn't quite as good makes little sense. If the money's that tight, then a standard lens project makes more sense, where you can get excellent focus on a 15" panel. If you want the resolution and throw, then you're already deciding that the factors are more important. I'd rather do it once, and do it right.

First of all the modified lens over at DIYPC does not cost $30, it costs $130, you left out the 1 buddy. And secondly, even with the modified lens it cannot hold a candle to the LL pro lens that has a 650mm focal length. If you want to build a projector that can compete with entry and mid level 720p commercial projectors then the LL pro lens is the only way to go. No other lens will even come close with corner to corner focus and brightness.

Lumenlab does not rip people off, I've surfed around for other places and have been into building projectors for almost two years now. Believe me when I say, they are indeed the best site for prices and info about DIY projectors that you will find.

Actually, no, we were talking about the Science Surplus from the getgo. DIYPC got brought into the post. The Surplus lens is $29 something. And to modify it, is a diy thing. Also, Christmas's projector uses a 17", I have built a 17", so I know this lens gives equal results as my 15". I did not know the Pro was 650mm FL? I have never stating anything about LL overcharging or anything. I personally have ordered from here. Funny how I started as a defender of here and there, and now have become under attack. So much for trying to be the good person in all of this.

Since when did I attack you? Nothing in my post was inflammatory at all. Please don't play the victim when nothing has happened to you. Honestly, what would I gain from attacking you? We like to keep things civil and helpful on these forums. I thought you guys were talking about the DIYPC lens because I saw it mentioned in here in that context, my mistake. I know the $30 lens you speak of, and that would honestly never give you 1/16th the results that the pro lens would. And correct me if I'm wrong; but it sure seemed as if you were saying that the pro lens was not worth it because you could get "similar" results for much less money...

calm down people.

The LL pro is 500mm focal.

Your inputs are very welcome miedoso, your tests on the mod as well as your efforts on making a working lens are very apreciated by most of us.

The only thing we are requesting is that you have already said are coming soon, so I will not repeat myself. The pictures will be checked not only by me but lot of members here.

The only thing I will NEVER understand is why is it you the one that has to show us the mod works.

Oh I thought it was 650mm, my mistake.

Gentlemen...
Its time to make a decision.
Either this series of exchanges gets a little more civil or the thread gets closed. We try to foster respect and helpfulness here and this does not appear to be either. Its time to collect our thoughts and bring this discussion back from becoming a flame war.
It sounds like there IS some merit to this discussion, so please lets reign it in and see what comes of it.

SamuraiJack

That's cool. Now, I would guess the reason would have to be, cost. I am guessing Alan doesn't have the money to buy a 17"? But, I can't answer for him, I just know many people appear to have money, and they don't.

Not sure why exactly you are directing that towards me as well... I was simply having a civilized debate with him, I didn't flame him even once.

Were cool, no problem.

Its the thread in general.
Just reign it in a bit guys!
Sometimes these discussions take on a life of their own and all hell breaks loose. Im just trying to keep that from happening.

Blake, sorry you took that personally. Like I said, its the whole thread.

SJ

As Rox stated, ""The pictures will be checked not only by me but lot of members here.'"" So let's just wait for the pics and see how it all turns out.

Ah I see, yeah it's cool guys. Just a simple misunderstanding, glad we all remained civil. Damn this community of DIYers freakin rules! You see now this is why this site is so awesome.

If any one really has the mythical 22" fl A/O triplet then it may have close to the same FOV as the pro lens and a longer fl too. Now that’s a show down I like to see.

I'm just glad to see the 18" Buhl triplets as cheep as they are, it give us another choice for building. Because they were made by the thousands the unit cost is low. I don't think they are a cheep lens in any way. If we had to have them made they would cost more than the pro lens because of the size, they are larger than the pro lens and made in the USA not CHINA.

I'm not kidding my self either I have seen the focus of the 18” fl Buhl and it is good on a 17" but not perfect , and what if you needed to do lens shifting? Everyone has said that the pro lens is RAZOR sharp on a 17" LCD. I'm still waiting for some one to use a 21" LCD and the pro lens just need to find a rear Fresnel. Cool

I just want to watch movies so a little soft on the edges is fine for me. I may end up some day with a larger lamp too and then the larger diam will help too.

Well my 2 cents here.

If you look in my Plog you will see that I switched from the Pro lens to an 18" WHY ?

It was about 10% brighter for one. Also the throw was perfect for my setup. I have my projector all the way against the back wall and ith the Pro lens I had about 3" of screen not filled. With the 18" my entire 180" screen is filled.

I'm using a 15.4" Wuxga which is more like a 16:9 screen but I get corner to corner focus with it. Here's a pic of my lens.

http://www.wavetel.us/~jonjandran/457.jpg

http://www.wavetel.us/~jonjandran/4572.jpg