Hi everybody,
this is my first post here... I decided to try to make a projector a while ago and thought I'd go the OHP + lcd projector way, but was disappointed with the specs on the aging lcd projectors.
So I bought a Viewsonic VG151 and a 3M 1895 after some consideration. The VG151 was definitely not designed for OHP use in mind... I was surprised that I could contort the cables to the point that I did without any problems.
After reading around, I thought that I could order two fresnels from optolec.com, cut them to size, and it would be the perfect solution for the 15" fresnel problem.
Unfortunately, the two fresnels had very different optical properties from the one that the OHP uses... so I'm stuck using a fresnel that chops off the edges for now.
Here are some pics I took of the setup... I still have quite a bit of image tweaking and fiddling to do, and the ductape is temporary as well. Sorry about the bad picture quality...
Here are the two fresnels side-by-side for comparison after I cut the optolec ones to size, the ones from optolec on the left and a random other OHP on the right:
Here are two crappily-taken image pictures:
Does anybody know where to find big fresnels that work for projection? I blew way too much on those optolecs...
this is my first post here... I decided to try to make a projector a while ago and thought I'd go the OHP + lcd projector way, but was disappointed with the specs on the aging lcd projectors.
So I bought a Viewsonic VG151 and a 3M 1895 after some consideration. The VG151 was definitely not designed for OHP use in mind... I was surprised that I could contort the cables to the point that I did without any problems.
After reading around, I thought that I could order two fresnels from optolec.com, cut them to size, and it would be the perfect solution for the 15" fresnel problem.
Unfortunately, the two fresnels had very different optical properties from the one that the OHP uses... so I'm stuck using a fresnel that chops off the edges for now.
Here are some pics I took of the setup... I still have quite a bit of image tweaking and fiddling to do, and the ductape is temporary as well. Sorry about the bad picture quality...
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.
An externally hosted image should be here but it was not working when we last tested it.
Here are the two fresnels side-by-side for comparison after I cut the optolec ones to size, the ones from optolec on the left and a random other OHP on the right:
An externally hosted image should be here but it was not working when we last tested it.
Here are two crappily-taken image 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.
Does anybody know where to find big fresnels that work for projection? I blew way too much on those optolecs...
Hmmm, don't give up, there are soutions. And you're projector seems to be coming along nicley.
How big is your lcd? If its 15" then your in luck. Any more and I'm afraid you are quite possibly screwed 🙁
You can buy a fresnel at http://people.eecs.ku.edu/~astaples/projector/index.htm that is big enough.
Read my post regarding that at http://www.diyaudio.com/forums/showthread.php?postid=129643#post129643
How big is your lcd? If its 15" then your in luck. Any more and I'm afraid you are quite possibly screwed 🙁
You can buy a fresnel at http://people.eecs.ku.edu/~astaples/projector/index.htm that is big enough.
Read my post regarding that at http://www.diyaudio.com/forums/showthread.php?postid=129643#post129643
Ok I got a couple of questions.
how big are those fresnells? Did you cut that one yourself?
Also some points of advice.
It looks like a lot of light is escaping from your projector
-Seal the box up completely and but still leave the airflow area open
-Alot of light is escaping between the fresnel and the lens I tell you that. Once you have the right distance set, make a enclosure to make sure that all the light is not going off and instead goes into the lens.
-Paint all the wood BLACK, the blackest you can find. A lot of the light is not bouncing around their and your loosing your light.
how big are those fresnells? Did you cut that one yourself?
Also some points of advice.
It looks like a lot of light is escaping from your projector
-Seal the box up completely and but still leave the airflow area open
-Alot of light is escaping between the fresnel and the lens I tell you that. Once you have the right distance set, make a enclosure to make sure that all the light is not going off and instead goes into the lens.
-Paint all the wood BLACK, the blackest you can find. A lot of the light is not bouncing around their and your loosing your light.
Morien: it is a 15"... wow, thank you for that link!
AJ Bertelsen: I cut those fresnels from the 16"-20" TV screen magnifier at optelec.com Here's the link: http://www.optelec.com/ProductDisplay.asp?ProductID=140 That's good advice about sealing the box up and painting it, I was going to seal it up when I got around to it but I didn't think it would affect the image quality that much. I didn't even think about painting it...
Does anybody know why the edges of the image seem to be bowed out?
Maybe it's related to my projector lens? Should I get something else, or is the 3m 1895 lens good enough?
AJ Bertelsen: I cut those fresnels from the 16"-20" TV screen magnifier at optelec.com Here's the link: http://www.optelec.com/ProductDisplay.asp?ProductID=140 That's good advice about sealing the box up and painting it, I was going to seal it up when I got around to it but I didn't think it would affect the image quality that much. I didn't even think about painting it...
Does anybody know why the edges of the image seem to be bowed out?
Maybe it's related to my projector lens? Should I get something else, or is the 3m 1895 lens good enough?
Hey, that looks like a pincushion error you need service mode. Ohh wait... Thats CRT technology.. (Jokeing!!)...
Anyways I think that the bowed out image is caused by the image (LCD) being too big for the projector lens. Thats why everything inside looks good.
Would a larger diameter lens of the same focal length fix this?
Experts?
Regards... Havok!
Anyways I think that the bowed out image is caused by the image (LCD) being too big for the projector lens. Thats why everything inside looks good.
Would a larger diameter lens of the same focal length fix this?
Experts?
Regards... Havok!
Fresnel
I have the same problem with those fresnels and the light.
Meanwhile very unhappy ....
and with the quality of an Nview and Proxima 822
which i have also tried both i was also not really lucky.
i will follow this Single Board Computer (SBC-675)
with Flatpanel connector way now. This will take a while because
i had to route a printed circuit board for Displays
with LVDS interface , but if this will function i can
then tell the device driver that i didn't want to scale up
at lower resolutions.
So i hope to get at 800x600 picture with black borders
around and my 15" is then only a 11.7" display which
i have to project. That's in the limits of any OHP.
Off topic 🙂)))
Can someone send me this awesome "actress/celebrity" wallpaper. (or the link)
This is a true "award" reference picture.
I have the same problem with those fresnels and the light.
Meanwhile very unhappy ....
and with the quality of an Nview and Proxima 822
which i have also tried both i was also not really lucky.
i will follow this Single Board Computer (SBC-675)
with Flatpanel connector way now. This will take a while because
i had to route a printed circuit board for Displays
with LVDS interface , but if this will function i can
then tell the device driver that i didn't want to scale up
at lower resolutions.
So i hope to get at 800x600 picture with black borders
around and my 15" is then only a 11.7" display which
i have to project. That's in the limits of any OHP.
Off topic 🙂)))
Can someone send me this awesome "actress/celebrity" wallpaper. (or the link)
This is a true "award" reference picture.
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