Ok, first a brief rundown of my design. I'm using a 400W Metal Halide bulb in a elliptical reflector. The first lens I have is an aspheric condensor lens followed by a fresnal (for now a page magnifier). Ontop of the fresnal is my projectrion panel and then comes the projection lens from a 3M 9700 overhead projector.
My first question is how important is it to have the condensor lens at the F2 position of the reflector? I know I'm close (within an inch or two) and it glows like the sun but not enough light seems to be getting throught my panel.
My second question is how much time did it take you sucessgul DIY'ers to allign all your optics? I have just spent about 3 hours with little progress. Although I must admit that I haven't mounted the projection lens yet but at this point the LCD hardly seems bright enough so I doubt that matters....
Impart your wisdom oh successful ones....😕
My first question is how important is it to have the condensor lens at the F2 position of the reflector? I know I'm close (within an inch or two) and it glows like the sun but not enough light seems to be getting throught my panel.
My second question is how much time did it take you sucessgul DIY'ers to allign all your optics? I have just spent about 3 hours with little progress. Although I must admit that I haven't mounted the projection lens yet but at this point the LCD hardly seems bright enough so I doubt that matters....
Impart your wisdom oh successful ones....😕
I'll be following this thread for a bit 😉 I'm not "allowed" to start building my PJ box till after Xmas my wife made me take down my temporary screen (bedsheet) till after Xmas and the box will be assembled in the living room...so it's gotta wait also. Just like a kid...I can't wait for Christmas ..just for different reasons 😉
For now I'm using a junk elmo OHP and a junk PC to watch movies in the kitchen, but I had to put the DVD back into my primary machine so the kids could watch The Grinch LOL so it looks like I wont be projecting much now till after boxing day 🙁
zardoz
For now I'm using a junk elmo OHP and a junk PC to watch movies in the kitchen, but I had to put the DVD back into my primary machine so the kids could watch The Grinch LOL so it looks like I wont be projecting much now till after boxing day 🙁
zardoz
suggestion
take the sheet back, hang it, wait till your wife starts complaining, wrap the sheet around the wife, put here in a huge box with xmas wrapping, send this box the slowest way you can to your parents in law, buy the kids lots of cookies and chocolate milk, make sure they eat at least 2 days nothing else, result they get sick, send them to the hospital, final result YOU can watch movies as much as you want till 2003! while working on your project without hassle.
Jean-Pierre
(this advice was free and donated by the local chapter of G.M.L.B.T.W.I.U.T.B)
take the sheet back, hang it, wait till your wife starts complaining, wrap the sheet around the wife, put here in a huge box with xmas wrapping, send this box the slowest way you can to your parents in law, buy the kids lots of cookies and chocolate milk, make sure they eat at least 2 days nothing else, result they get sick, send them to the hospital, final result YOU can watch movies as much as you want till 2003! while working on your project without hassle.
Jean-Pierre
(this advice was free and donated by the local chapter of G.M.L.B.T.W.I.U.T.B)
I apologize
Sorry guys, I should actually have done a more through search of the board. I figured out that the fresnal I have from Staples is a single where I need a double fresnal. I realized this after my second parts ohp arrived today and I removed the fresnal to discover that it's actually two stuck together. Slapped that one on the projector and even in daylight I can see a difference. Much more light is making it through to the LCD now. Once I figure out all the focal points tonight it should be full steam ahead. I should have something up and running by the end of the week.😀
Sorry guys, I should actually have done a more through search of the board. I figured out that the fresnal I have from Staples is a single where I need a double fresnal. I realized this after my second parts ohp arrived today and I removed the fresnal to discover that it's actually two stuck together. Slapped that one on the projector and even in daylight I can see a difference. Much more light is making it through to the LCD now. Once I figure out all the focal points tonight it should be full steam ahead. I should have something up and running by the end of the week.😀
uvodee
LOL she says you are off her Christmas card list.
PS I have a fridge carton in the shop...hehe...allready has air holes cut 😉
zardoz
LOL she says you are off her Christmas card list.
PS I have a fridge carton in the shop...hehe...allready has air holes cut 😉
zardoz
Projection Lens
Ok, I didn't realize how little light the projection lens needs to generate a decent image. Everything is progressing well at this point except for one problem. The projected image has a dark semi-circular band encompassing one corner. I know this is from the dimple in the top of my Metal Halide bulb, but how do I correct the problem?? I have done a brief search but haven't really found anything relavent (there is just to much to search through). See the image below for a better explaination.
Ok, I didn't realize how little light the projection lens needs to generate a decent image. Everything is progressing well at this point except for one problem. The projected image has a dark semi-circular band encompassing one corner. I know this is from the dimple in the top of my Metal Halide bulb, but how do I correct the problem?? I have done a brief search but haven't really found anything relavent (there is just to much to search through). See the image below for a better explaination.
Attachments
Re: Projection Lens
i think a) you could try changing the position of the lamp itslef,
b) if you are using a fresnel in between, try roatating it a bit.
my 2cents
J-P
i think a) you could try changing the position of the lamp itslef,
b) if you are using a fresnel in between, try roatating it a bit.
my 2cents
J-P
Thanks Uvodee
After a lot of trial and error I believe that the you are right. The lamp may not be exactly at the F1 point and I may have to adjust it. The circle effect is definately from the dimple in the top of the lamp. Can anyone confirm if this is a likely solution?
After a lot of trial and error I believe that the you are right. The lamp may not be exactly at the F1 point and I may have to adjust it. The circle effect is definately from the dimple in the top of the lamp. Can anyone confirm if this is a likely solution?
bitbyter
What lamp are you using? I have both GE and Sylvania lamps here, I find the Sylvania's are much "cleaner" light and dont have the dimple that the Ge's do. They do however have a much clearer image of the arc tube visible, it so far hasnt presented a problem.
For the time being I'm using an old junk OHP that does a MUCH better job than I ever thought it might, I'm sweating the light and optics issues much less now. I can do better than this junky old elmo anyday, it uses a ENX bulb aimed at a mirror then up through the frezzie...LCD screen then the low end optics of the OHP head.
And it looks really crisp from corner to corner, this gives me big expectations for my PJ box when it get's done.
hehe...the Xmas tree comes down tomorrow.....room to play..
zardoz
What lamp are you using? I have both GE and Sylvania lamps here, I find the Sylvania's are much "cleaner" light and dont have the dimple that the Ge's do. They do however have a much clearer image of the arc tube visible, it so far hasnt presented a problem.
For the time being I'm using an old junk OHP that does a MUCH better job than I ever thought it might, I'm sweating the light and optics issues much less now. I can do better than this junky old elmo anyday, it uses a ENX bulb aimed at a mirror then up through the frezzie...LCD screen then the low end optics of the OHP head.
And it looks really crisp from corner to corner, this gives me big expectations for my PJ box when it get's done.
hehe...the Xmas tree comes down tomorrow.....room to play..
zardoz
Re: bitbyter
i don't vare for your room to play, but why does the christmas tree comes down is my question...
your christmas tree as well as ours should not come down on before jan 7 2003 how else can you evoke the figurines of the 3 Kings, they cannot did not show up till jan 6 ....
Jean-Pierre
(completely speachless now, will never understand Americans, even while living between them and with one!)
zardoz said:
i don't vare for your room to play, but why does the christmas tree comes down is my question...
your christmas tree as well as ours should not come down on before jan 7 2003 how else can you evoke the figurines of the 3 Kings, they cannot did not show up till jan 6 ....
Jean-Pierre
(completely speachless now, will never understand Americans, even while living between them and with one!)
Bulb Type
I am currently using a phillips bulb. Thanks for the advice though, I'll check around here and see if I can find any sylvania bulbs. Just a small point Uvodee....Zardoz and I are both CANADIANS!!! Also my family usually keeps our tree up until after New Years but until now I didn't know why (confirmed the three kings thing with my Dad)...
I am currently using a phillips bulb. Thanks for the advice though, I'll check around here and see if I can find any sylvania bulbs. Just a small point Uvodee....Zardoz and I are both CANADIANS!!! Also my family usually keeps our tree up until after New Years but until now I didn't know why (confirmed the three kings thing with my Dad)...
want to borrow a map?
Hi there, I'd just like to clear up a couple of things. Firstly I won't persecute you for your relligious beliefs, even though they are not my own. Some of my wife's family are "Gosphel Hall" they dont have a tree at all....(something about worshipping a tree get's them cranky) but they still cellebrate Christmas. My wifes father is Dutch and a "Roman Catholic in good standing" and his tree is down on New Years day every year (he firmly believes in the three kings). On my "personelle files" in the army I am listed as NRE (which somehow the millitary see's as No Religious Afilliations) I suppose they didnt feel comfortable withn NRA for obvious reasons..
I have a very open view on the topic of religion, my kid's arent baptised. My wife and I decided that "finding your religion" is a very personal thing, and we dont really have the right to choose for our children. We offer them the choices and some day they will decide which to follow. If my daughter becomes Buhdist I will still love her and respect her, likewise if she were to choose the way of Wican. My son can claim Judaism or follow the teachings of Vishnu, it's his choice.
My point is if the heart is good and the intent is pure it doesnt matter what you believe in.
I dont watch hockey,but it was invented here....we are the worlds greatest peace keepers, but our army runs on debt... we defend our finacial assets poorly, but will defend our borders to the death...we believe in medicinal marijuana, but it's still against the law to smoke it...We are not perfect, but I AM CANADIAN!
zardoz
Hi there, I'd just like to clear up a couple of things. Firstly I won't persecute you for your relligious beliefs, even though they are not my own. Some of my wife's family are "Gosphel Hall" they dont have a tree at all....(something about worshipping a tree get's them cranky) but they still cellebrate Christmas. My wifes father is Dutch and a "Roman Catholic in good standing" and his tree is down on New Years day every year (he firmly believes in the three kings). On my "personelle files" in the army I am listed as NRE (which somehow the millitary see's as No Religious Afilliations) I suppose they didnt feel comfortable withn NRA for obvious reasons..
I have a very open view on the topic of religion, my kid's arent baptised. My wife and I decided that "finding your religion" is a very personal thing, and we dont really have the right to choose for our children. We offer them the choices and some day they will decide which to follow. If my daughter becomes Buhdist I will still love her and respect her, likewise if she were to choose the way of Wican. My son can claim Judaism or follow the teachings of Vishnu, it's his choice.
My point is if the heart is good and the intent is pure it doesnt matter what you believe in.
I dont watch hockey,but it was invented here....we are the worlds greatest peace keepers, but our army runs on debt... we defend our finacial assets poorly, but will defend our borders to the death...we believe in medicinal marijuana, but it's still against the law to smoke it...We are not perfect, but I AM CANADIAN!
zardoz
uvodee said:
Re: want to borrow a map?
If you would have started by saying you were Canadian, living in heu heu Canadia i supose, that would have cleared every confusion!
I am Belgian, we live ON compromises and not only do we have the diamond Capital of the World Antwerpen (for women) we also make the best BEER (for men) , but we don't take it both ways!!! 😉
Jean-Pierre
zardoz said:
If you would have started by saying you were Canadian, living in heu heu Canadia i supose, that would have cleared every confusion!
I am Belgian, we live ON compromises and not only do we have the diamond Capital of the World Antwerpen (for women) we also make the best BEER (for men) , but we don't take it both ways!!! 😉
Jean-Pierre
bitbyter:
Can you post specs (and pics if possible) of your MH lamp and reflector? I am using an elliptical reflector with a small MH lamp and have a thread dedicated to MH, reflector, finding F1 and F2, etc.
Here is the link:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=7864&perpage=15&pagenumber=4
Can you post specs (and pics if possible) of your MH lamp and reflector? I am using an elliptical reflector with a small MH lamp and have a thread dedicated to MH, reflector, finding F1 and F2, etc.
Here is the link:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=7864&perpage=15&pagenumber=4
Do a screen make Difference??
Yeeehaww!! My projector is up and running and I'm getting a great sharp image. However, it does still seem a little dark, not much better that the crap OHP I braught home from work. It is true that it doesn't fade as much as I move the projector back (thus making the image bigger) but I was wondering how much a proper screen actually brightens up the final results??? Right now I'm just proejecting onto my bedroom wall. I'll try and get some pictures up tonight....This has been the best Christmas ever!! 😀
Yeeehaww!! My projector is up and running and I'm getting a great sharp image. However, it does still seem a little dark, not much better that the crap OHP I braught home from work. It is true that it doesn't fade as much as I move the projector back (thus making the image bigger) but I was wondering how much a proper screen actually brightens up the final results??? Right now I'm just proejecting onto my bedroom wall. I'll try and get some pictures up tonight....This has been the best Christmas ever!! 😀
Prgress Report & Fine Tuning
I now have my screen up and it seems to have helped a bit. However, the image does seem to darken as you look towards the upper right hand corner and the whole screen narrows towards the bottom. Also, the top of the screen seems to be out of focus. I'm getting really tired of trial and error fine tuning... Does anyone have some suggestions that could help me out??.
I now have my screen up and it seems to have helped a bit. However, the image does seem to darken as you look towards the upper right hand corner and the whole screen narrows towards the bottom. Also, the top of the screen seems to be out of focus. I'm getting really tired of trial and error fine tuning... Does anyone have some suggestions that could help me out??.
Re: Prgress Report & Fine Tuning
The picture narrowing at the bottom is called keystoning. It's caused by your image being projected at an angle against your screen (i.e., the projector is pointed upwards.) When you fix this, it will probably fix the top of the image being out of focus.
bitbyter said:I now have my screen up and it seems to have helped a bit. However, the image does seem to darken as you look towards the upper right hand corner and the whole screen narrows towards the bottom. Also, the top of the screen seems to be out of focus. I'm getting really tired of trial and error fine tuning... Does anyone have some suggestions that could help me out??.
The picture narrowing at the bottom is called keystoning. It's caused by your image being projected at an angle against your screen (i.e., the projector is pointed upwards.) When you fix this, it will probably fix the top of the image being out of focus.
Fresnel Lens
I was doing some browsing on the forum today and noticed that someone had mentioned that the fresnel lens must be bigger than the LCD. My fresnel is bigger but the aperature that the light come through to reach the fresnel is not much bigger than the LCD panel it'self. Personally I cannot come up with a reason why the lighted area of the fresnel should be bigger than the LCD and do not really want to modify my set-up until someone can explain this to me. So. the question is: Does the lighted area of the fresnel lens need to be bigger than the LCD and why??
I was doing some browsing on the forum today and noticed that someone had mentioned that the fresnel lens must be bigger than the LCD. My fresnel is bigger but the aperature that the light come through to reach the fresnel is not much bigger than the LCD panel it'self. Personally I cannot come up with a reason why the lighted area of the fresnel should be bigger than the LCD and do not really want to modify my set-up until someone can explain this to me. So. the question is: Does the lighted area of the fresnel lens need to be bigger than the LCD and why??
size of frasnel
IMHO the function of the frasnel is to collect and focus light to the projection lens (see the drawing). If this is true, than the LCD should be smaller than the Frasnel and the light coming out of the frasnel should cover the LCD panel to get even illumination.
In my MH lamp thread (http://www.diyaudio.com/forums/showthread.php?s=&threadid=7864&perpage=15&pagenumber=3), we have discussions about how the off center placement of MH lamp arc can affect the intensity of light at the focal point.
IMHO the function of the frasnel is to collect and focus light to the projection lens (see the drawing). If this is true, than the LCD should be smaller than the Frasnel and the light coming out of the frasnel should cover the LCD panel to get even illumination.
In my MH lamp thread (http://www.diyaudio.com/forums/showthread.php?s=&threadid=7864&perpage=15&pagenumber=3), we have discussions about how the off center placement of MH lamp arc can affect the intensity of light at the focal point.
Attachments
Making Progress
After a long fight with bronchitis I am back to tinkering. I have adjusted the position of my condenser lens and the image has brightened up nicely. Alas, my keystoning problem still exists, I have tried everything I could think of to fix this but nothing seems to have helped. Could it possibly be the panel it'self?? Could a malfunction in the Projection Panel throw off the keystoning?? It seems my only recource now is to try a software fix (you can supposedly do it with any Nvidia card). Does anyone else have any keystone correction advice before I try this? As I stated in and earlier post, the image narrows towards the bottom.
After a long fight with bronchitis I am back to tinkering. I have adjusted the position of my condenser lens and the image has brightened up nicely. Alas, my keystoning problem still exists, I have tried everything I could think of to fix this but nothing seems to have helped. Could it possibly be the panel it'self?? Could a malfunction in the Projection Panel throw off the keystoning?? It seems my only recource now is to try a software fix (you can supposedly do it with any Nvidia card). Does anyone else have any keystone correction advice before I try this? As I stated in and earlier post, the image narrows towards the bottom.
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