| ahhhh i need a lens, and fan question - Click HERE for Original Thread |
| part2wanksta |
ahhh help i need a lens
so the lens i am using is a singlet. it freakin sucks. but one reason it sucks is because i have only 1 fresnel; in front. i havent cut my split frenels yet.
so if anyone knows where i can get one locally. but i prolly wont find one. so than does anyone know where ican order one.
i also have a fan question
i have a fan blowing air on a block of wood without a hole cut in back of it. is this a problem. i dont think that cold air is getting anywhere. so my lcd is getting real hot.]
anyone know the maximum heat that a ps1 lcd can take |
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| HiLLBiLLY |
I have heard Amercians say they get fresnels from "Staples" not sure what this is myself. You could also go for a cheap page magnifyer, you can buy them in Australia from Chemists Stores and some Newsagents. Think you call Chemists Drug Stores in the U.S? Might want to wander into one and ask about them there mate.
Dunno what your PS1 screen can put up with heat wise other than to say if it starts getting black spots on the screen you are viewing, it is too hot LoL
Not really sure what you mean by the way you have your fan setup, maybe a picture or a rough scetch in Paintshop or even Paint would make this easier to understand :-) |
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| part2wanksta |
i have frenels already. i just havent cut them yet.
what do you think about this.
fresnel-fresnel-lcd-fresnel--------lens
the lens that i need is like a triplet or something. |
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| HiLLBiLLY |
| I think u need one less fresnel Part :-) |
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| TaskMaster |
HiLLBiLLY,
Staples is a large chain of office supply stores in the US, Canada, UK, and Germany. The page magnifiers (fresnels) people get there can be seen on their website here. |
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| part2wanksta |
| well i figured that since there were no holes that air could not come in so i cut out the holes |
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| will1384 |
| quote: | | I have heard Amercians say they get fresnels from "Staples" |
I got 2 of them for about $7 each - there nice looking, thick
and well made - and the size of a sheet of paper - 2x
magnification - the thickness is about that of a OHP
fresnel or about 3 CDs in thickness
I have yet to use them so I dont know how well they
will look - but they look nice |
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| HiLLBiLLY |
| I figured it must have been some type of office supply company chain as people all over the US have reported they got them there. We have Office Works here but they dont have them lol,,,Chemist do but hey are garbagae, thick as two sheets of paper and half the size lol |
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| part2wanksta |
help me i need a lens. all i am using now is a singlet, and it sucks
i need some kind of triplet or copy lens, does anyone know where i could get one locally |
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| tjh |
For a lens it is a long shot, but you could try local pawn shops or any surplus stores you have around. In Rhode Island there really isn't anything locally here so I'm stuck ordering online.
Anyone know what the focal length of those page magnifiers from Staples is? Thanks. |
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| Guy Grotke |
triplets: The focal length you need depends on the LCD size, the throw distance you want, and the image size you want. Once you figure all those out, then surplusshed.com has some copy lenses you might look at. Or you might find an OHP at a yard sale, used business equipment store, school surplus sale, etc. If the OHP has a single lens an inch or two thick, that is a triplet. Probably around 325 mm fl. If the OHP has two lenses, then that is a duplet which would work much better than your current magnifying glass! (Just not quite as good as a triplet.) If you do gut an OHP, you can use the lens & the fresnels. (As long as the fresnels are big enough for your LCD.)
fresnels at office supply store: You can estimate focal length by focussing the image of a light bulb that's more that 30 feet away. (The further away, the better the estimate.) Then just measure the distance from the fresnel to the image. Numbers like "2X" and "3X" don't mean much because they are only valid at a certain (unknown) distance! If they list a Diopter strength, then fl = 1000/Diopters. When you get the fresnel outside, you can measure it precisely using the sun instead of a light bulb. Don't set anything on fire! |
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| HiLLBiLLY |
| quote: | | Don't set anything on fire! |
Speaking from past experience there are we Guy hehe :-p |
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| Guy Grotke |
I just don't want anybody getting arrested for arson when the office supply people see them trying to measure a focal length in the parking lot!
I used to do this procedure out on our wooden deck, but it freaked out my wife to see the little bit of smoke from a short board propped up to match the angle of the sun. Now I go out to the gravel driveway and use a paving stone. |
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| HiLLBiLLY |
| quote: | | but it freaked out my wife |
HAHA Guy
The women just don't understnad us fellas lol they must learn that small sacrifices must be made in the name of "science"
hehehe |
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| Steamer |
Listen, Wanksta,
A good source of lenses is American Science and Surplus
Scroll down to the projection lenses section. You should be able to find what you need there.
Much success to your project!
Steamer |
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| part2wanksta |
| what is the average shipping time that surplus shed takes to ship |
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| Guy Grotke |
They get your shipment out pretty quick. Like the next day or so. Then it is up to UPS. I think you could pay for second or even next day shipping if you want to pay extra.
But what's wrong with those American Science lenses? They are cheap and the 5", 7.8", and 9" focal length projection lenses all have wider aperatures than that surplus shed lens. (It won't be easy to get much light through that surplus shed lens.) You need a wide aperature because the image of the lamp arc your fresnels create will be multiplied by the ratio of the fresnel focal lengths. For example, with 220 & 330 mm fl fresnels, it would be 1" * (330/220) = about 1.5" across. So you need at least a 38.1 mm aperature just to receive all the light.
If I were you, I'd go with the 9" focal length lens. That would give you a 62" diagonal image from 10 feet. You would be able to put your projector at the back of the room (much nicer) and still get a nice bright image. It would also be a good fit to a 330 mm fl field fresnel an inch or two before the LCD. (unsplit fresnels) |
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| Andronico |
I agree with you Guy, I bought three 9" focal lenght units for testing purpose and works very well in my Lilliput prototype !
And the price is good !
;) |
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| part2wanksta |
just for confirmation this is the lens i should buy correct
69071 PROJ. LENS, 9.0" F:5.6 9" F:5.6 2-11/16" 3-1/4" $9.50/EACH
ALSO WILL IT BE PRETTY CLOSE TO TRIPLET QUALITY |
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| Andronico |
This is the lens that I bought
:) |
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| part2wanksta |
ok i am going to order 2 of these lenses today.
um for the fresnels what focal length do i need them to be at. |
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| Guy Grotke |
Those are too short for a field fresnel for the 9" fl projection lens. For the condensor fresnel one of these would be okay. You just put the lamp at the focal length of the condensor fresnel. For these fresnels, that would be 7" or 178 mm.
The field fresnel has to have a longer focal length than 7". I calculated that you would need a 330 mm fl field fresnel with the 9" projection lens. Instead of this pair of 178 mm fresnels, you should look for a pair that are 220 mm & 330 mm. This is a very common pair used in many overhead projectors. You can also find this combination at most of the DIY projector web stores.
If you try to use the pair of 178 mm fresnels, most of the light would not even hit your projection lens!
The rule of thumb is that your field fresnel fl has to be a bit longer than your projector fl. But that rule of thumb gets people in bad situations all the time. The real math is:
1/LCD to proj lens = 1/fl - 1/proj lens to screen
If you put your projector 10 feet from the screen, then the distance from the 9" projector lens to the LCD will be 9.73" or 247 mm. A 250 mm fl fresnel an inch past your LCD would be great. It would focus an image of the lamp arc right into the middle of your projection lens. But i don't know where you can get a 250 mm fl fresnel. You could use a 220 mm fresnel about 2 inches past your LCD, but I am not sure how that would look. It might distort the image too much. I know you can use a 330 mm fresnel if you put it about 65 mm before your LCD. Just make sure the fresnels are cut wide enough so the cone of light converging at the projection lens lights the entire LCD where it intersects. |
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| part2wanksta |
so i am about to order the 9" fl lens but i need to order up to 10$
69034 PROJ. LENS, 4.25" F:4.5 4-1/4" F:4.5 1-3/8" 1-1/2" Mtd on plate $3.95/EACH
69045 PROJ. LENS, 5" F:3.5 5" F:3.5 50mm 52mm Anastigmat $3.95/EACH
would any of these lenses work for any lcd. if so than i will buy one of these to so i can have the 10$ minimum order |
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| Guy Grotke |
Here are some fresnels you could use with that 9" projection lens:
www.3Dlens.com
click on the OHP Fresnel lens button. For a small LCD, either of these would work. You will probably want to cut them (a Dremel cutting wheel is good) just to make your projector box a reasonable size. Get everything working together to get a focussed screen image before you cut them. Then you can apply masking tape to the areas you will cut away on all four sides, to make sure that the resulting fresnels will still light the whole LCD.
Put them in the light path with the 210 or 220 mm fl fresnel smooth side toward the lamp. The spacing will be the focal length of which ever one you get. (210 or 220 mm) Put the 330 mm fresnel smooth side facing away from the lamp, right on the shorter fresnel. With 2-3 inches between the fresnels and the LCD, you should get a nice focussed image of the lamp arc right in the projection lens. You can see it if everything is spaced right, by holding a piece of white paper where the projection lens will go. |
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| Steamer |
They also have a pretty good size 1st surface mirror. If you order 2 of those I think it will put you right over the $10 mark. I ordered 1 9" lens and 2 1st surface mirrors and it worked out pretty good.
Steamer |
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| onie |
Guy,
I have a 210mm FL and 215mm FL copy lens with 220mm FL Fresnel.
Is this a good combination?
I read from another forum that we should go for the same or a little higher FL for Fresnel compared to Proj Lens.
Light -> Fresnel(220mmFL)->LCD->ProJ Lens(210mmFL)
I plan to use one fresnel only.
Should the fresnel be placed before or after the LCD?
Does it matter?
Mind you that I use a big parabolic reflector like 9" in diameter with a mirror finish that I found from a garage sale.
My LCD is 7". |
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| Guy Grotke |
I will assume you want a throw distance of 10 feet, to get a 95" diagonal picture. Then the distance from the LCD to the projection lens would be:
1/LCD to lens = 1/fl - 1/10 feet = 225 mm
If you put the field fresnel before the LCD, then it needs to go at least 10 mm before it, so you don't see rings in the final image. You also need the image of the lamp arc to focus in the projection lens, not before it:
225 + 10 + 10 = 245 mm fl fresnel needed
So your 220 mm fl fresnel is too short to put it before the LCD. You will need to put it after the LCD, ridged side facing the LCD. With 10 - 15 mm spacing between the LCD and the fresnel, it should be perfect.
Setup your projector and adjust your projector lens so you get a focussed screen image, using the throw distance you want to use in the final product. Then remove the projection lens and the LCD, and put a piece of white paper where the lens was. You should see a small circle of light. Move the paper back and forth. The smallest circle should be where the lens was. If not, then you need to adjust the position of the fresnel until it does. That spacing will give you the brightest picture. |
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| onie |
Wow! Thanks Guy!
I'll try that when I get home. |
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| part2wanksta |
i need a fresnel lens that is 4" by 5 1/2"
my light is gonna be 8" to 9" away from the fresnels.
it will be two fresnel together. the focal length of my lens is 9"
is this lens possible to make. or is it just not out there |
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| part2wanksta |
| oh yeah and one more question, after the people from american science ship their product do they send out a email or no. i got it shipped priority |
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| Steamer |
If I remember correctly they send an email to the effect of: "A package was sent to this address, if this is a gift please don't read further" I guess because alot of people send their stuff as gifts to others. You will get it soon...
BTW, GUY,
I got the 7" lense from them, and after I got my lenses and obj. lens aligned, I noticed the iris in the center seems to be melting after only a couple hours. now the center lens in the assembly is cloudy and the color in the resulting image is more washed out. It is not as rich as it was before. It is still well in focus, as I can see great detail in the image, but just not as colorful. Any Ideas?
Steamer |
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| Guy Grotke |
Sure. Get a standard 220 + 330 mm fl overhead projector fresnel pair. (DIY online stores have them, as well as 3dlens.com.) Then cut them down to the dimensions you need. Put them 220 mm from the lamp (8.66"). Then leave about 2-3 inches before the LCD. That should put your projection lens right at the converged image of the lamp arc.
Before cutting your fresnels you might want to just put masking tape around the four sides where you plan to cut. Then you can try the whole projector out to see that they still light the entire LCD. They will have to be bigger than the LCD, since the light will be converging over that 2-3 inch distance before it reaches the LCD. |
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| Guy Grotke |
A melting iris sounds like you have too much IR in your light. You need some kind of IR mirror or filter in the light path before it even reaches the LCD. Your condensor system is just focussing all of that IR right inside your projection lens, and burning it up!
Washed out colors could be from light scattering because of the lens problem, or it could be UV bleaching out your LCD's color filters. If you don't have a UV filter in your light path, I suggest you add one.
Once you have cleaned up your UV & IR, then maybe a new lens is in order! |
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| ace3000_1 |
| quote: | | A melting iris sounds like you have too much IR in your light. |
MILES!!! too much especially melting an iris in a projection lens.
| quote: | | Once you have cleaned up your UV & IR, then maybe a new lens is in order! |
Id see if you can strip it first, if it hasnt afected your coatings all it will take is a clean.
Trev:) |
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| HiLLBiLLY |
| Personally I would be a whole lot more worried what effect the IR has had on the LCD! pocket change for a new lens...LCD is a little different :-p |
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| part2wanksta |
ok i already got that email so i am assuming that they sent it out yesterday.
does anyone know where to get a ffc extention cable for psone screen |
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| I_eat_flowers |
hey part2wanksta,
you can get those cables her. 6 bux shipped.
cut ten of the pins and it'll fit. dunno whether you need the pins on same side or opposite side. check this out before otherwise your panel will be destroyed.
how to extense? put the pins face to face. take care they are aligned. wrap a sticky tape around. now cut two lil rubber plates and plasticplates and drill two holes in. put the cable between and squeeze it between the plates with the screws. that's it. |
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| part2wanksta |
| is theere anywhere that i could get longer |
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| part2wanksta |
| hey guy my lcd is actually 8 1/2 inches from my light. so now is there a fresnel that will suit me |
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| Steamer |
Fortunately, I have yet to put the LCD in the light path. I have since acquired a good piece of tempered glass along with a sheet of UV film. But I don't think that addresses the IR problem. I don't know where to get a good sized hot (or cold) mirror.
Steamer |
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| TaskMaster |
| quote: | Originally posted by part2wanksta
i need a fresnel lens that is 4" by 5 1/2"
my light is gonna be 8" to 9" away from the fresnels.
it will be two fresnel together. the focal length of my lens is 9"
is this lens possible to make. or is it just not out there |
| quote: | Originally posted by Guy Grotke
Sure. Get a standard 220 + 330 mm fl overhead projector fresnel pair. (DIY online stores have them, as well as 3dlens.com.) Then cut them down to the dimensions you need. Put them 220 mm from the lamp (8.66"). Then leave about 2-3 inches before the LCD. That should put your projection lens right at the converged image of the lamp arc. |
I have a fresnel that is unsplit and is a combo focal like the one mentioned by Guy. My problem is that it was just a tad smaller than the width of my 15" lcd I plan to use :( so I am going to order another that is 15" x 15". If you'd like to buy this one I'll sell it for $25 shipped which is a bit less than I ended up paying. |
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| Steamer |
I have a small piece of IR/UV filter from American Science and Surplus. It is just big enough that I can place it between the bulb and condenser. It has a dot on one side, I assume to indicate which side is the coated side. Which side do I face toward the light source? The coated side? Same question for the UV film.
Steamer |
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| will1384 |
| quote: | | noticed the iris in the center seems to be melting after only a couple hours |
I had small problem like that in a way
I use a D.I.Y. OHP and when the LCD is not setting on the OHP
the plastic that holds the mirror smokes in just a few seconds
at the bottom edge near the lens - It was melted a little
when I bought the OHP that I striped for parts -
But yea if the lens is melting you got problems - just think
about your eyes - skin cancer stuff like that
UV will yellow plastic - IR will melt it - or thats what
I have ben told |
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| Guy Grotke |
30 pin 0.5 mm FFC cables, sockets, & extenders:
lumenlab.com
diybuildergroup.com
mouser.com
digikey.com |
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| Guy Grotke |
Put it with the coated side toward the lamp. It absorbs less and reflects more heat that way.
surplusshed.com has some 50 mm by 55 mm hot mirror tiles, but I think they may not be very effective
diybuildergroup.com has some 50 mm by 50 mm hot mirror tiles, and they work very well. You can build a frame to hold 4 of them right next to your lamp.
diyprojectorcompany.com has a plastic heat film mounted on glass that would have to go just before your fresnels.
exclusiv-online.com has a UV & IR filter. (Easier to get if you are in the EU.)
Other ideas: Tempered glass (doesn't do much), KG-<n> heat absorbing glass (expensive & cuts some visible red), water-filled filter( too complex)
Did I miss anything? |
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| Guy Grotke |
yes, that's all you do.
It has two parts:
A female-to-female adapter made from two ZIF sockets, back to back.
A standard FFC cable in 3", 6". or 12" length.
Disconnect your LCD's FFC cable & socket
Plug your LCD's cable into one side of the adapter
Plug the extender cable into the other side of the adapter
Plug the other end of the extender cable into your LCD's socket
It takes longer to explain than it does to do it! |
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| part2wanksta |
i have a new box.
the box is 22" 14" 8 1/2"
the reason for this is because of brightness.
i have a unsplittfresnel that was cut unevenly.
but it still seems like it isnt bright because of either my fresnels or my reflector or maybe my doublet lens or my 250w bulb is not a universall mount.
so i should get my new lens tommorow, and i hope that is the problem.
but if not i have the new box to fit me |
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