prjctr_builder said:
answer: yes you can...
asuming these numbers are the focal lemghts and you put it together with no distance between it you 'l get a lense system with a focal length of 124,1 mm. that is really big magnifing lense.
the shorter the focal length the bigger the magnification...
after doing some more research, i think it is a littl ebit more complicated than i thought at first, but it is still solvable...i think i have to take care of the fresnel lense too...
i wanna try not to waste any light just because of too big magnification...
i'll come up with more next week, as i sit down to think for the weekend...
I have the same problem with my projector as you can see in the picture my projector is close to the screen, it;s about 4 feet away, but it still shows really good. It has alot of glare but the light was on I'm going to put a light tint on a piece of plexiglass and put it over the screen to reduce glare.
That formula thats on page 104 on this board was first posted by me awhile ago, I got it from the 3M website.
And Don't Laugh At Me For Watching Power Puff Girls😡
That formula thats on page 104 on this board was first posted by me awhile ago, I got it from the 3M website.
And Don't Laugh At Me For Watching Power Puff Girls😡
Attachments
REFLECTOR
most of you guys probably know how important it is to have a good reflector... when i was making mine, it took me a while, but i managed to make a VERY nice, as i personally think reflector. I have made a parabolic one and it covers the whole bulb. i have plans for it which i will photocopy and post on a website or just post a pic here. the plans consist of the left, right and the parabolic sude, it is hard to explain, but once you see it, you'll ge the idea. i used sheet of steel and the good thing is that i can solder it with a common soldering iron. i do not know if the solver will get too hot and melt if you are running a 400W bulb, but i am running a 250W and everything is just fine. I had my projector on for 2.5 hours straight today and it did not overheat at all.
My setup:
Light= 250w MH bulb with a ballast
LCD= 15" viewsonic VE150
Fresnel= DUKANE 4003 fresnel
Objective=DUKANE 4003 327mm focal length (i need 520-530mm)
Cooling= 4 80mm 12v fans (32 cfm) which all run off 9v power supply. I will upgrade to 18v power supply if i will have any issues with cooling
Screen= 6 by 4.5 feet made of snow white synthetic leather
thank you guys....
P.S.
you know what, i am gonna go and order 3 lenses off ebay with different focal lengths and play around with them, see if i can get any luck. after using gunawan's program it seems to me that we can use pretty much any lens to achieve what we want, at certain distances, that is...
most of you guys probably know how important it is to have a good reflector... when i was making mine, it took me a while, but i managed to make a VERY nice, as i personally think reflector. I have made a parabolic one and it covers the whole bulb. i have plans for it which i will photocopy and post on a website or just post a pic here. the plans consist of the left, right and the parabolic sude, it is hard to explain, but once you see it, you'll ge the idea. i used sheet of steel and the good thing is that i can solder it with a common soldering iron. i do not know if the solver will get too hot and melt if you are running a 400W bulb, but i am running a 250W and everything is just fine. I had my projector on for 2.5 hours straight today and it did not overheat at all.
My setup:
Light= 250w MH bulb with a ballast
LCD= 15" viewsonic VE150
Fresnel= DUKANE 4003 fresnel
Objective=DUKANE 4003 327mm focal length (i need 520-530mm)
Cooling= 4 80mm 12v fans (32 cfm) which all run off 9v power supply. I will upgrade to 18v power supply if i will have any issues with cooling
Screen= 6 by 4.5 feet made of snow white synthetic leather
thank you guys....
P.S.
you know what, i am gonna go and order 3 lenses off ebay with different focal lengths and play around with them, see if i can get any luck. after using gunawan's program it seems to me that we can use pretty much any lens to achieve what we want, at certain distances, that is...
i ordered my eyeglass today and they told i will have it in about 1 week.
You shpuld have seen the face of the salesman as i ordere ONE eyeglass... 😕
so results next week; hopefully i will have finished my new projector then too...
You shpuld have seen the face of the salesman as i ordere ONE eyeglass... 😕
so results next week; hopefully i will have finished my new projector then too...
bad news 
as i experienced it is only possible to get eyeglasses in dioptrin with 1/8 steps, that means it is not possible to get a -0,012 dioptrin lense like in my case ;-(((
the salesman ordered an -0,125 eyeglass for me, but that is for no use, i chancelled the order and now i am thinking about planing my room new to get the perfect image.
You know... it the prayer doesn't come to the mountain, then the mountain must be brought to the prayer... (it is a german proverb, i don't know if it exits in english but that wold be the exact (wrong) translation)
as i experienced it is only possible to get eyeglasses in dioptrin with 1/8 steps, that means it is not possible to get a -0,012 dioptrin lense like in my case ;-(((
the salesman ordered an -0,125 eyeglass for me, but that is for no use, i chancelled the order and now i am thinking about planing my room new to get the perfect image.
You know... it the prayer doesn't come to the mountain, then the mountain must be brought to the prayer... (it is a german proverb, i don't know if it exits in english but that wold be the exact (wrong) translation)
prjctr_builder
i think a found a lens for you..
http://www.surplusshed.com/pages/item/l3043.html
508 mm focal length
don't know if i got everything right, but it sounds good to my, and for 15 dollars you cant do anything wrong...
i think a found a lens for you..
http://www.surplusshed.com/pages/item/l3043.html
508 mm focal length
don't know if i got everything right, but it sounds good to my, and for 15 dollars you cant do anything wrong...
right now i am looking for a projection lense with 380mm focal length and a diameter of at least 60mm. may be someone can help me??? best would be a three lens system...
please call me moron!!!!!!
i made my calculations in the wrong units...
i used millimeters instead of meters...
but dioptrin is 1/m...
my vacations are too long... 😉
i made my calculations in the wrong units...
i used millimeters instead of meters...
but dioptrin is 1/m...
my vacations are too long... 😉
ok here are my new calculations:
i have an ohp lens with a fl of 290 mm = 0.29 m = (1/0.29) 3.45 dioptrien
my object size should be 1.54 m
my room has 3.15m space for that projector thing
the distance between lens and screen should be something around 2.35 m
so my ideal lens would have an fl of 385 mm = 0.385 m = 2.6 dp
that means my adiotnal lens must have 2.6 - 3.45 = - 0.85 dp
but as i know they only have 1/4 steps here in germany that means my lens must have - 0.75 dp... (in the US they have 1/8 steps)
the distance between lens and screen is then 2.31m, the distance of lens and TFT is 0.442m and with the light which has 0.30m i am in my borders; i have 3.05m all in all and can move the projector 10 cm back for the picture to fit...
so tomorrow I'll go buy such a an eyeglass... wish me luck 🙂
i have an ohp lens with a fl of 290 mm = 0.29 m = (1/0.29) 3.45 dioptrien
my object size should be 1.54 m
my room has 3.15m space for that projector thing
the distance between lens and screen should be something around 2.35 m
so my ideal lens would have an fl of 385 mm = 0.385 m = 2.6 dp
that means my adiotnal lens must have 2.6 - 3.45 = - 0.85 dp
but as i know they only have 1/4 steps here in germany that means my lens must have - 0.75 dp... (in the US they have 1/8 steps)
the distance between lens and screen is then 2.31m, the distance of lens and TFT is 0.442m and with the light which has 0.30m i am in my borders; i have 3.05m all in all and can move the projector 10 cm back for the picture to fit...
so tomorrow I'll go buy such a an eyeglass... wish me luck 🙂
Re: slize, wait!!!
327 mm = 0.327 m = 3.06 dp
521 mm = 0.521 m = 1.92 dp
1.92 dp - 3.06 dp = - 1.14 dp
that means you need to go to the optician and buy an eyeglass with -1.125 dp for farsightedly people (because they only have 1/8 steps in the US)
or you try to find a convex - conkav lense with - 876 mm of focal lenght...
hope that helps...
prjctr_builder said:
327 mm = 0.327 m = 3.06 dp
521 mm = 0.521 m = 1.92 dp
1.92 dp - 3.06 dp = - 1.14 dp
that means you need to go to the optician and buy an eyeglass with -1.125 dp for farsightedly people (because they only have 1/8 steps in the US)
or you try to find a convex - conkav lense with - 876 mm of focal lenght...
hope that helps...
If you guys need help just ask the guys at www.edmundoptics.com they can help you. I email them about this topic they gave me some info but my is for a smaller lcd and a different focal length just email them with your problem and they will help. I got my message in one day.
rmccoll said:
True, they will help you. But you will probably end up being convinced to buy on of their products which i hope you all know are not cheap.
my point:
If you need help, just ask for it in this forum, that way we will all learn something from each other. And it will cost you nothing...
good luck all, Aleksey
🙂
Re: prjctr_builder
Slize, you are my savior...
I am about to order the lens as soon as i finish typing this post.
this lens will be perfect for me....
thanks man
slize said:
Slize, you are my savior...
I am about to order the lens as soon as i finish typing this post.
this lens will be perfect for me....
thanks man
How are you going to use it? Look at the picture View #2:
It's too long.
How about this?
80 mm dia, 400 mm FL (it's only doublet though):
An externally hosted image should be here but it was not working when we last tested it.
It's too long.
How about this?
80 mm dia, 400 mm FL (it's only doublet though):
An externally hosted image should be here but it was not working when we last tested it.
Check out this lcd from tiger direct here is the web site, it's a clearence sale $159 after rebate $189 before http://www.tigerdirect.com/applications/searchtools/item-Details.asp?EdpNo=576468&sku=M333-1000
there's nothing really great about that LCD. It is almost the same size as my 15" LCd and my LCD has way better specs and also mine was FREE. But anyways, you can get an LCd monitor similar to mine for about 150$ off ebay....