Maybe I found a replacement for the collimating fresnel lens. I have no idea what this lense is called like in english, but in german it's called "Integrationslinse". On Google you can't find **** about it with this word.
Some german guy wrote about it here.
Looks like this lense kills the hotspot effect.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Some german guy wrote about it here.
Looks like this lense kills the hotspot effect.
My condenser lens at www.diylabs.org also kills the hotspot effect. Also, splitting your fresnel lens seems to greatly improve how even your light distrobution is, but I don't know if it would cure a hotspot.
[RPD]-Killer,
Could that possibly be a fresnel lenslet array? They are available--I've wondered from time to time if they would be helpful in making the light more even against the LCD--especially if more than one light is used in the light engine. If I remember correctly the lenslet arrays are available in a variety of forms (hex, rectangular, etc.). But I have never gone ahead and experimented with one. I do have one on order--I'll try to play with it in the next month or so. Should be interesting though...?
p.s. I'm new to post here--right now I am working on a rather different type of setup. If it works out, I will post images of it's setup and results. If not... well I'll just keep my embarrassment to myself!
Could that possibly be a fresnel lenslet array? They are available--I've wondered from time to time if they would be helpful in making the light more even against the LCD--especially if more than one light is used in the light engine. If I remember correctly the lenslet arrays are available in a variety of forms (hex, rectangular, etc.). But I have never gone ahead and experimented with one. I do have one on order--I'll try to play with it in the next month or so. Should be interesting though...?
p.s. I'm new to post here--right now I am working on a rather different type of setup. If it works out, I will post images of it's setup and results. If not... well I'll just keep my embarrassment to myself!
Indeed you should! I've never had any problems with hotspots with my setup, but the hotspots are usually a biproduct of the placement of the elements as opposed to their quality. For example, you'll probably get a hotspot if you put the lamp too close to the first fresnel lens or if you have a reflector that isn't positioned correctly (usually too far away).
If you ever purchase a DIY product and it doesn't work like it should, I will always be available to help you figure out if it is a positioning problem. If a part is bad, then of course I'll simply buy it back from you. I'm hoping that DIY Labs will be around for a while, so I'll always do my best to ensure that you are happy with DIY Labs!
If you ever purchase a DIY product and it doesn't work like it should, I will always be available to help you figure out if it is a positioning problem. If a part is bad, then of course I'll simply buy it back from you. I'm hoping that DIY Labs will be around for a while, so I'll always do my best to ensure that you are happy with DIY Labs!
i agree. Letting the community know about your ideas can be invaluable for many reasons. Obviously if you find something that works, we all want to know also, but i'm equally interested in knowing what doesn't work. That saves others the time it takes to try a method that we know doesn't work - that helps us all find something that does work much more effeciently.
With regards to peri's lens, i think you or anyone else should definitely try it. The only reason I haven't tried it yet is that i just don't have the time! Let us know what you find or if you have any questions. I know that www.surplusshed.com often has those types of lenses.
Happy new year everyone!
With regards to peri's lens, i think you or anyone else should definitely try it. The only reason I haven't tried it yet is that i just don't have the time! Let us know what you find or if you have any questions. I know that www.surplusshed.com often has those types of lenses.
Happy new year everyone!
fresnel lenslet arrays
Hello all
Yes, I checked with Surplus Shed (I've purchased a few lenses from them already) but unfortunately Fred wrote back indicating that they were not available at the moment; however, I am to check his site (daily? weekly? I'm not sure about the frequency) and perhaps they will one day be available. There are alternative sources, though.
I would love to post about everything that I'm doing--as I go--but I think I would be more comfortable posting after something is rather more complete, when I have more to say other than "testing this out" etc. The reason being: I have spent literally the last 5 days reading every post here (yes, there are a few, and yes, I did have plenty of free time!) and gleaning as much information as I could. I have learned a great deal from all of the posts, to be sure. However, I would rather post something different, something new, instead of just a repeat of prior posts
Needless to say--I am photographing everything as I go, as much as I can. I have a few different LCDs and lenses and bulbs and ballasts (the shop next door is an electrical shop, and the owner likes to experiment, so I have some help there). Much of it is still on the way, a bit of it is here. As soon as everything is here I can really begin testing different combinations. Plus, I have a few old projectors, both overhead and slide, and I'm interested in seeing what different combinations I can pull from those sources, just for fun. Right now, my photographs are mainly just of components, not of any casing or shells.
Regarding the cases or shells, I've drawn up 2 general plans--just pencil on paper, no "blueprints" per se yet (won't do that unless something works). One is for a larger LCD, and one is for a smaller LCD--12 to 14" and 4 to 6" respectively, thereabouts. They are--at least in my opinion--a bit "unusual"
I was interested in a 10.4" LCD, but apparently most of them are lower resolution--I am trying to stick with XVGA and up. My first preference is for contrast of 400:1 as a minimum; anything higher preferred (my experience is that, dollar for dollar, higher contrast gives a better picture over any other consideration--at least for movies). By the way, does anyone know anything about this: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3067530239&category=1498&rd=1 -- !NeW! 10.4 TV screen only DVD LCD monitor--. I have emailed the person twice, but haven't received a response. I have a JILI type LCD controller card--which in theory would work with a compliant LCD panel, if that is indeed such a panel. However, I am concerned that the item listing indicates "TV" rather than monitor--I am thinking therefore that the quality of the LCD would be lower--but this is just a guess (based on my mentioned research into 10.4 LCD available specs).
Alright, I've rambled on a bit. Hope I haven't sounded too stuffy! If I do, it's probably because I'm a crotchedy old grandmother!
Best to all--hope everyone has a fun and safe New Year's,
-Peri
Hello all
Yes, I checked with Surplus Shed (I've purchased a few lenses from them already) but unfortunately Fred wrote back indicating that they were not available at the moment; however, I am to check his site (daily? weekly? I'm not sure about the frequency) and perhaps they will one day be available. There are alternative sources, though.
I would love to post about everything that I'm doing--as I go--but I think I would be more comfortable posting after something is rather more complete, when I have more to say other than "testing this out" etc. The reason being: I have spent literally the last 5 days reading every post here (yes, there are a few, and yes, I did have plenty of free time!) and gleaning as much information as I could. I have learned a great deal from all of the posts, to be sure. However, I would rather post something different, something new, instead of just a repeat of prior posts
Needless to say--I am photographing everything as I go, as much as I can. I have a few different LCDs and lenses and bulbs and ballasts (the shop next door is an electrical shop, and the owner likes to experiment, so I have some help there). Much of it is still on the way, a bit of it is here. As soon as everything is here I can really begin testing different combinations. Plus, I have a few old projectors, both overhead and slide, and I'm interested in seeing what different combinations I can pull from those sources, just for fun. Right now, my photographs are mainly just of components, not of any casing or shells.
Regarding the cases or shells, I've drawn up 2 general plans--just pencil on paper, no "blueprints" per se yet (won't do that unless something works). One is for a larger LCD, and one is for a smaller LCD--12 to 14" and 4 to 6" respectively, thereabouts. They are--at least in my opinion--a bit "unusual"
I was interested in a 10.4" LCD, but apparently most of them are lower resolution--I am trying to stick with XVGA and up. My first preference is for contrast of 400:1 as a minimum; anything higher preferred (my experience is that, dollar for dollar, higher contrast gives a better picture over any other consideration--at least for movies). By the way, does anyone know anything about this: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3067530239&category=1498&rd=1 -- !NeW! 10.4 TV screen only DVD LCD monitor--. I have emailed the person twice, but haven't received a response. I have a JILI type LCD controller card--which in theory would work with a compliant LCD panel, if that is indeed such a panel. However, I am concerned that the item listing indicates "TV" rather than monitor--I am thinking therefore that the quality of the LCD would be lower--but this is just a guess (based on my mentioned research into 10.4 LCD available specs).
Alright, I've rambled on a bit. Hope I haven't sounded too stuffy! If I do, it's probably because I'm a crotchedy old grandmother!
Best to all--hope everyone has a fun and safe New Year's,
-Peri
I like your philosophy about trying a method before commenting on it. If you are photographing your work, then I think you can help everyone out a lot! If you ever need anything (parts, advice, or otherwise) then just let me know by emailing me at astaples@diylabs.org. If and when you get your projector running, I could create a section on my website for your projector, including steps you took, results, and anything else you might want to contribute.
That LCD panel that you were asking about might be a good panel, but you'd need a compatible LCD controller for it since it doesn't come with one. I've never put together my own LCD/controller kit, but I do know that you'll need a power supply (usually easy to get or make) and you'll need to make sure that the LCD and the controller support the same resolutions and that the controller you use has the correct connector for the LCD ribbon cable. If you do use this LCD panel, just make sure to keep it cool by pusing cool air over both sides. You may even want to use an IR filter or a cold mirror. www.surplusshed.com has a few cold mirrors for a little money right now. I got one and it looks pretty "cool"
That LCD panel that you were asking about might be a good panel, but you'd need a compatible LCD controller for it since it doesn't come with one. I've never put together my own LCD/controller kit, but I do know that you'll need a power supply (usually easy to get or make) and you'll need to make sure that the LCD and the controller support the same resolutions and that the controller you use has the correct connector for the LCD ribbon cable. If you do use this LCD panel, just make sure to keep it cool by pusing cool air over both sides. You may even want to use an IR filter or a cold mirror. www.surplusshed.com has a few cold mirrors for a little money right now. I got one and it looks pretty "cool"
Projector Dimensions
Hi,
I am new here and I have a few questions for you guys. First, I wa wondering if there are any basic dimensions to use when building a custom box projector. For instance, are there specific basic distances used for mounting the bulb, fresnels, LCD panel and projection lens? Like how far should the first fresnel be from the bulb? How far should the LCD be from the fresnel? How far should the second fresnel be from the LCD? How far should the second fresnel be from the projection lens? Does having a reflector and condensor change these dimensions at all?
Couple more questions:
Do any of you have any good pictures that show how you mounted the LCD and Fresnels in to the box? I have many different ideas on how to do this, but I want to know the most common way.
Is it better to use a 4oo watt MH bulb or a 250 watt MH bulb? I am sure the 400 is better for daytime watcing, but doesn't it get a lot hotter? They are about the same price, so that doesn't really matter
Does the triplet lens used for the prjection lens have adjustmesnt? I guess what i mean is...How do you focus the image when projecting it? Does the projection lens turn similar to a camera lens or what?
Has anyone used the XGA Theater to hook up DVD players and TV tuners to your DIY projectors? Does it work well? What does it do exactly?
How do you change the contrast after you have already built the enclosure? Do you open the box and change the contrast a little at a time?
Well, that'll do it for now. Thanks for you help. I am starting to understand all of this, but still need some of that newbie help. I am probably going to buy the guide at lumenlabs.com. Then one day I may customize it or something.
Thanks again.
Later
Hi,
I am new here and I have a few questions for you guys. First, I wa wondering if there are any basic dimensions to use when building a custom box projector. For instance, are there specific basic distances used for mounting the bulb, fresnels, LCD panel and projection lens? Like how far should the first fresnel be from the bulb? How far should the LCD be from the fresnel? How far should the second fresnel be from the LCD? How far should the second fresnel be from the projection lens? Does having a reflector and condensor change these dimensions at all?
Couple more questions:
Do any of you have any good pictures that show how you mounted the LCD and Fresnels in to the box? I have many different ideas on how to do this, but I want to know the most common way.
Is it better to use a 4oo watt MH bulb or a 250 watt MH bulb? I am sure the 400 is better for daytime watcing, but doesn't it get a lot hotter? They are about the same price, so that doesn't really matter
Does the triplet lens used for the prjection lens have adjustmesnt? I guess what i mean is...How do you focus the image when projecting it? Does the projection lens turn similar to a camera lens or what?
Has anyone used the XGA Theater to hook up DVD players and TV tuners to your DIY projectors? Does it work well? What does it do exactly?
How do you change the contrast after you have already built the enclosure? Do you open the box and change the contrast a little at a time?
Well, that'll do it for now. Thanks for you help. I am starting to understand all of this, but still need some of that newbie help. I am probably going to buy the guide at lumenlabs.com. Then one day I may customize it or something.
Thanks again.
Later
I'm not familiar with that paricular panel, but as long as it has the video inputs that you need (VGA vs. RCA/Svideo) and it can render at least several thousands of colors, then it would be okay. Ideally you'd want to have a panel that can render upwards of 1 million colors, but I've built projectors that were fun to use that could only display 4,000 colors. If you have an eBay auction link, feel free to email it to me if you want an opinion about a particular panel - sometimes I see fine print that others don't see or perhaps I'll have used that particular panel before, in which case I can give better advise. There is also an LCD read me on my website at www.diylabs.org/projector/ if you click on the "LCD" link in the site's menubar.
movin 2002 and more
Hi you guys!! Again another, nothing knowing, newbie;
My name is Frank live in Holland and study chemistry.
I have read my wy around this forum and I must say it is GREAT!! Big applaus for you all. I realy learned a lot and learing still more by reading more topics. I realy love the subject; single vs multiple lightsources.
Also one thing i have to say is: It is hard for a newbie to read up to 114 pages of replies.
Ok i also wanna ad something to the board. I found more information on the MOVIN 2001/2002. It is still sold in germany (second hand). It is the last single panel projector (as early was told in this topic)
Contrast: 500:1
ANSI-lumen: 250
4x50W Xenon lamps
Hi you guys!! Again another, nothing knowing, newbie;
My name is Frank live in Holland and study chemistry.
I have read my wy around this forum and I must say it is GREAT!! Big applaus for you all. I realy learned a lot and learing still more by reading more topics. I realy love the subject; single vs multiple lightsources.
Also one thing i have to say is: It is hard for a newbie to read up to 114 pages of replies.
Ok i also wanna ad something to the board. I found more information on the MOVIN 2001/2002. It is still sold in germany (second hand). It is the last single panel projector (as early was told in this topic)
Contrast: 500:1
ANSI-lumen: 250
4x50W Xenon lamps
Oops..2nd try
Ok my computer was faster then I wanted it to be so some more information through pictures!
Oh the size is 11,5"x11,5"x23" Not very big
Ok my computer was faster then I wanted it to be so some more information through pictures!
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Oh the size is 11,5"x11,5"x23" Not very big
How to get the most light out of your bulb
I have now for a long time though about how to get the most light out of the bulb, the OHP-design most of you are using is only using a very little bit of the hole light the bulb produce. Even with a very big condenserlens you loose over 40% of the light. The new idea is to use a normal PAR30 bulb, cut the bulb and place the HID-bulb in the middle, move it a little backward so you get a wider spread angle. The problem is that you can´t get as wide angle as with the ohp-design, so it will only light up the middle of the screen. The soulotion is to move the hole buld and reflector backwards so the light fills the hole lcd. But if we move the light backwards, the fresnellens will focus the light in the wrong place, depending on the focuspoint of the objectlens. And the big new thing is to remove the splited fresnel in front of the lcd, this will restore the light focus point to the objectlens. The only problem with this light-design is that the distans from the bulb to the fresnellens will be the double. But there is a soulotion to that also, use a mirror in 45 degrees angle, and the distans is the same as before. I´m using this thing now and it´s very bright only with a 150W HID bulb. You can use this design even with small lcd:s. It´s time to leave the OHP-light engine !
I have now for a long time though about how to get the most light out of the bulb, the OHP-design most of you are using is only using a very little bit of the hole light the bulb produce. Even with a very big condenserlens you loose over 40% of the light. The new idea is to use a normal PAR30 bulb, cut the bulb and place the HID-bulb in the middle, move it a little backward so you get a wider spread angle. The problem is that you can´t get as wide angle as with the ohp-design, so it will only light up the middle of the screen. The soulotion is to move the hole buld and reflector backwards so the light fills the hole lcd. But if we move the light backwards, the fresnellens will focus the light in the wrong place, depending on the focuspoint of the objectlens. And the big new thing is to remove the splited fresnel in front of the lcd, this will restore the light focus point to the objectlens. The only problem with this light-design is that the distans from the bulb to the fresnellens will be the double. But there is a soulotion to that also, use a mirror in 45 degrees angle, and the distans is the same as before. I´m using this thing now and it´s very bright only with a 150W HID bulb. You can use this design even with small lcd:s. It´s time to leave the OHP-light engine !
Attachments
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.