i am trying to build a lcd projector with a 640X480 lcd projection panel.
but the only problem i have is what type of lense to use!!
i think this is a common problem for many people so please help me!!
I have done alot of research and the fresnal lense in front of the monitor or tv is a pile of poo. and alot of people are using sinlet doublte and the higher quality triplet lenses. although there are other people who say the best lense is a Plano convex lense.
what would be the best/cheapest (well to a certain extent) for my purposes.
i want all the corners in focus and it to be a bright and clear image.
what are all the specs?? focal length, diameter and type???
the lcd panel i am curently bidding for on ebay is "Sharp computer projection panel QA350B"
please help me!!!!!
but the only problem i have is what type of lense to use!!
i think this is a common problem for many people so please help me!!
I have done alot of research and the fresnal lense in front of the monitor or tv is a pile of poo. and alot of people are using sinlet doublte and the higher quality triplet lenses. although there are other people who say the best lense is a Plano convex lense.
what would be the best/cheapest (well to a certain extent) for my purposes.
i want all the corners in focus and it to be a bright and clear image.
what are all the specs?? focal length, diameter and type???
the lcd panel i am curently bidding for on ebay is "Sharp computer projection panel QA350B"
please help me!!!!!
Stop bidding!
Hi there, I don't know a lot about lenses, but on that panel you're bidding on - from what I remember it is no good for our purposes.
Someone posted on it a while ago and apparantly it won't project video!
Do a search for the "sharp qa350" in the forum, and on google and you should find the specs.
Hi there, I don't know a lot about lenses, but on that panel you're bidding on - from what I remember it is no good for our purposes.
Someone posted on it a while ago and apparantly it won't project video!
Do a search for the "sharp qa350" in the forum, and on google and you should find the specs.
is this true???
i couldn't find any thing on it!!
lenses lenses lenses?????????????
oh, i am thinking of using a 400w metal halide setup for my back light... but there are very expensive.
what othe powerful light setups are good 'n' cheap????
i couldn't find any thing on it!!
lenses lenses lenses?????????????
oh, i am thinking of using a 400w metal halide setup for my back light... but there are very expensive.
what othe powerful light setups are good 'n' cheap????
Sharp QA-350B 640x480 1.4M(?) Passive matrix, dual scan.
You will proably be best using an Over Head Projector with a projection panel, maybe not the 350 though. Many OHPs have triplet lenses.
You will proably be best using an Over Head Projector with a projection panel, maybe not the 350 though. Many OHPs have triplet lenses.
Here's a review of the 350
http://www.onlinemag.net/OL1995/MayOL95/connolly.html
Looks like the last line might be the most significant.
"
Stone brushes off the Sharp QA-350 with the comment that it
manages to live "down" to passive-matrix standards, but this unit
generated positive enthusiasm elsewhere. Michelle DeMaio, in _PC
LapTop Computing Magazine_, claims that the $2995 Sharp
transformed her approach to work. Although it reproduces only 512
colors, Sharp's dual-scan passive-matrix technology "produces higher
contrast, better color saturation, and faster response time than
conventional single-scan passive-matrix panels," she says, and the
result is a screen image that is "really quite good." It also worked
right out of the box.
George Beekman, in the July 1994 _Macworld_, reports that the QA-
350 "fared surprisingly well" in direct comparison with an active-
matrix panel. Both were "crisp, bright, and easy to read" from a
distance, although rapid movements produced blurred but still visible
images on the Sharp. This unit, Beekman concludes, would be "an
economical alternative for presenters who don't need multimedia
capability."
http://www.onlinemag.net/OL1995/MayOL95/connolly.html
Looks like the last line might be the most significant.
"
Stone brushes off the Sharp QA-350 with the comment that it
manages to live "down" to passive-matrix standards, but this unit
generated positive enthusiasm elsewhere. Michelle DeMaio, in _PC
LapTop Computing Magazine_, claims that the $2995 Sharp
transformed her approach to work. Although it reproduces only 512
colors, Sharp's dual-scan passive-matrix technology "produces higher
contrast, better color saturation, and faster response time than
conventional single-scan passive-matrix panels," she says, and the
result is a screen image that is "really quite good." It also worked
right out of the box.
George Beekman, in the July 1994 _Macworld_, reports that the QA-
350 "fared surprisingly well" in direct comparison with an active-
matrix panel. Both were "crisp, bright, and easy to read" from a
distance, although rapid movements produced blurred but still visible
images on the Sharp. This unit, Beekman concludes, would be "an
economical alternative for presenters who don't need multimedia
capability."
Lenses and Lights
Thought i'd add a bit on lenses, as no-one else has. It is generally agreed in this forum that the absolute best type of lens is the Triplet projection lens, people have said that it is a significant improvement over a doublet or singlet projection lens.
All of the above lenses typically come from Overhead Projectors - which is probably what makes them difficult/not easy to come by as the majoriety of them are attached to ohps. The only readily available source of triplet lenses that I have heard of is those sold by the DIY projector company, for $34.
http://www.diyprojectorcompany.com/catalog/product_info.php?cPath=23&products_id=38
I'm going to use a standard OHP for my set up - I will have an infocus TVT 3000 panel (640x480 active matrix, but only VGA input) and an older style 250 watt halogen ohp (which probably has a singlet or doublet lens). I've found it a bit difficult to find out how this will perform, as most people are using far more expensive light sources, such as MH kits. On other sites that i've seen people have said that an ohp such as the one I am getting will provide a good projection if watched in a room with no other lights on. This isn't a problem for me as I only want to watch the odd film in the evening, but it might be for others. anyway, i'm collecting the OHP this weekend so i'll post some results when in two weeks, as i'm going on holiday directly aftwer getting it.
On other powerful light sources - the main problem is that of heat, in that there are plenty of strong lightsm but they run very hot and so don't work well in a PJ. This is the reason why the more proficient DIYers turned to MH as it is far cooler. Have you looked at Undream's website? He posted a diary of his building - it is very good as he started out with very little knowledge and his diary takes you through all the alternatives that he found before completing a good projector: http://www.dreamlash.com/DIY/index.php?postid=1
If you go to the date 04/21/02 he talks about different light sources.
This is pretty much the same as doughboy said, but more verbose, I hope it's useful though.
good luck
Thought i'd add a bit on lenses, as no-one else has. It is generally agreed in this forum that the absolute best type of lens is the Triplet projection lens, people have said that it is a significant improvement over a doublet or singlet projection lens.
All of the above lenses typically come from Overhead Projectors - which is probably what makes them difficult/not easy to come by as the majoriety of them are attached to ohps. The only readily available source of triplet lenses that I have heard of is those sold by the DIY projector company, for $34.
http://www.diyprojectorcompany.com/catalog/product_info.php?cPath=23&products_id=38
I'm going to use a standard OHP for my set up - I will have an infocus TVT 3000 panel (640x480 active matrix, but only VGA input) and an older style 250 watt halogen ohp (which probably has a singlet or doublet lens). I've found it a bit difficult to find out how this will perform, as most people are using far more expensive light sources, such as MH kits. On other sites that i've seen people have said that an ohp such as the one I am getting will provide a good projection if watched in a room with no other lights on. This isn't a problem for me as I only want to watch the odd film in the evening, but it might be for others. anyway, i'm collecting the OHP this weekend so i'll post some results when in two weeks, as i'm going on holiday directly aftwer getting it.
On other powerful light sources - the main problem is that of heat, in that there are plenty of strong lightsm but they run very hot and so don't work well in a PJ. This is the reason why the more proficient DIYers turned to MH as it is far cooler. Have you looked at Undream's website? He posted a diary of his building - it is very good as he started out with very little knowledge and his diary takes you through all the alternatives that he found before completing a good projector: http://www.dreamlash.com/DIY/index.php?postid=1
If you go to the date 04/21/02 he talks about different light sources.
This is pretty much the same as doughboy said, but more verbose, I hope it's useful though.
good luck
thanks for all your feed back. but i didn't get the sharp panel..
i am now thinking of buying a second hand (if i can find one) 7" lcd car dvd screen. or a new one. i have been looking and they are around $200 AUS. thats alot of money for a 16 year old.
the lcd screan are usualy 7 inches and only have composit/RCA
input. also would i be able to take it apart and put my halogen ligh at the back of it?????
another thing is i think they all plug into lighter sockets? can you get an adaptor.
is the quality of the image good or what??
the most important Question is .....
is it worth me spending 2 months worth of pay on it?
i know there is that liliput system or somthing in other forums, but they are computer screens not car dvd player screens.
if there is any info on this any where please let me know!!!
maybe some one could tell me whyere or what are cheap lcd screens, not lcd panels that are crap and you bid for them on ebay only to find out that in the last houre or so, some one else wants that lcd screen way way way more that you do...
so triplet lenses are all the rage huh??
this project started out a year ago with my crt 15" fish bowl of a montor and a fesnel lense i bough from my local optics store for $20 AUS.. for some unknown reason i couldn't get it into focus... i hang my head in shame for beleaving people off the internet.. but every one seems so friendly...............
i am now thinking of buying a second hand (if i can find one) 7" lcd car dvd screen. or a new one. i have been looking and they are around $200 AUS. thats alot of money for a 16 year old.
the lcd screan are usualy 7 inches and only have composit/RCA
input. also would i be able to take it apart and put my halogen ligh at the back of it?????
another thing is i think they all plug into lighter sockets? can you get an adaptor.
is the quality of the image good or what??
the most important Question is .....
is it worth me spending 2 months worth of pay on it?
i know there is that liliput system or somthing in other forums, but they are computer screens not car dvd player screens.
if there is any info on this any where please let me know!!!
maybe some one could tell me whyere or what are cheap lcd screens, not lcd panels that are crap and you bid for them on ebay only to find out that in the last houre or so, some one else wants that lcd screen way way way more that you do...
so triplet lenses are all the rage huh??
this project started out a year ago with my crt 15" fish bowl of a montor and a fesnel lense i bough from my local optics store for $20 AUS.. for some unknown reason i couldn't get it into focus... i hang my head in shame for beleaving people off the internet.. but every one seems so friendly...............
I am selling a lens and a lamp for pretty cheap.
I am selling a triplet lens for pretty cheap, I never realised that other websites sold them for $34.99 mine comes with a lamp and it's only 4.99. It's too late for me to change the price now so, it's up for a good deal to anyone that wants it!
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5709993580&ssPageName=STRK:MESE:IT
I am selling a triplet lens for pretty cheap, I never realised that other websites sold them for $34.99 mine comes with a lamp and it's only 4.99. It's too late for me to change the price now so, it's up for a good deal to anyone that wants it!
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5709993580&ssPageName=STRK:MESE:IT
What are the specifications for that lens? The focal length needs to be around 13" and the rear diameter should ideally be 2.5" or larger ... the rear element looks kinda small on that one. The lamp is worth at least $4.99 though, so I'm definitely not discouranging anyone from bidding on that auction.
The triplet lenses that we sell are well matched for most fresnel lenses (OHP style, not page magnifiers). You won't find higher quality - I guarantee it. We're not the only company to carry this particular lens, but whatever company you buy from - the triplet lens like we have is king.
by the way, the Sharp QA-350B has nowhere near 1.4 million colors ... it's closer to 1,024 colors if it is even color at all (I think that the "B" means "black" or monochrome, but I'm not for sure on that).
The triplet lenses that we sell are well matched for most fresnel lenses (OHP style, not page magnifiers). You won't find higher quality - I guarantee it. We're not the only company to carry this particular lens, but whatever company you buy from - the triplet lens like we have is king.
by the way, the Sharp QA-350B has nowhere near 1.4 million colors ... it's closer to 1,024 colors if it is even color at all (I think that the "B" means "black" or monochrome, but I'm not for sure on that).
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