Fender...The bulb isnt really the problem...I really need to find a balast to put these small bulbs in...does anyone know where I can find a cheap/complete solution. Or at least a high output and small balast???
But that link does rock...they got lots of stuff....thanks.
But that link does rock...they got lots of stuff....thanks.
SuperD,
I probably didn't explain it well...I think the DYS bulb does not need a ballast. You can just bypass the ballast/power supply that your OHP has and apply 120v wall power to the bulb. This is what the schematic that I posted earlier showed. So, basically, this could be an all-in-one solution to get higher output for your OHP for cheap.
Hopefully I am understanding you correctly...let me know if I am not.
undream,
Yeah, I am getting the feeling lately that this has become a 'How to juice up your OHP' thread, but in an indirect sort of way, it is applicable. The OHP design has the minimum number of elements that are needed for projection with large panels, so any attempt to improve on their application could be useful. It's probably more boring than designing things from scratch (which I am STILL trying to do, but things are going slow these days...school 🙁 ), but it's something.
Without a good reflector (look at the high precision of small projection lamps for an example) large enough to harness most of the light from the MV or MH bulbs, they will not be very useful for our purposes. It is possible, but it will take some work. I designed and built a fairly accurate, horizontal-plane elliptical reflector yesterday, and it wasn't as efficient as I thought it would be. If it was 360 degrees instead of a folded rectangle of metal, results would be much better. But I'm at a loss as to how to do this. Any ideas? Myren?
Anyways, good luck everyone! Hopefully, we will see some real innovation from the bright minds around here. 🙂
-f4
I probably didn't explain it well...I think the DYS bulb does not need a ballast. You can just bypass the ballast/power supply that your OHP has and apply 120v wall power to the bulb. This is what the schematic that I posted earlier showed. So, basically, this could be an all-in-one solution to get higher output for your OHP for cheap.
Hopefully I am understanding you correctly...let me know if I am not.
undream,
Yeah, I am getting the feeling lately that this has become a 'How to juice up your OHP' thread, but in an indirect sort of way, it is applicable. The OHP design has the minimum number of elements that are needed for projection with large panels, so any attempt to improve on their application could be useful. It's probably more boring than designing things from scratch (which I am STILL trying to do, but things are going slow these days...school 🙁 ), but it's something.
Without a good reflector (look at the high precision of small projection lamps for an example) large enough to harness most of the light from the MV or MH bulbs, they will not be very useful for our purposes. It is possible, but it will take some work. I designed and built a fairly accurate, horizontal-plane elliptical reflector yesterday, and it wasn't as efficient as I thought it would be. If it was 360 degrees instead of a folded rectangle of metal, results would be much better. But I'm at a loss as to how to do this. Any ideas? Myren?
Anyways, good luck everyone! Hopefully, we will see some real innovation from the bright minds around here. 🙂
-f4
reflector
If you wanna built reflectors, why not try a vacuum reflector. A round vessel, attach a reflecting foil (mylar...) pump out the air from from it until a parabolic or elliptical shape is reached. There exist DIY Vacuum Torus screens, why not vacuum reflectors. Also I've read about this on an astronomic hobby site, they also need large reflectors, but more spherical ones.
a limititation of this approach can be the choice of material due to the heat.
xblocker
If you wanna built reflectors, why not try a vacuum reflector. A round vessel, attach a reflecting foil (mylar...) pump out the air from from it until a parabolic or elliptical shape is reached. There exist DIY Vacuum Torus screens, why not vacuum reflectors. Also I've read about this on an astronomic hobby site, they also need large reflectors, but more spherical ones.
a limititation of this approach can be the choice of material due to the heat.
xblocker
Based on the wattage that LCD projectors use (the ones you buy), i believe that a projector that provides say 1200 lumens, is not using a 1200 lumen bulb. These things run at like 175 watts, so i think the acutal bulb produces higher lumens itself, but once the light goes through the lcd, the brightness fades, as is the problem with our setups. It would be nice to work up a calculation that would tell how many lumens of bulb light are equal to the lumens of the projected picture. This would allow us to chose a light source better.
ballasts
If you want a better ballast that come with the dusk to dawn lights http://www.advancetransformer.com/ They make every kind of ballast you would need.
If you want a better ballast that come with the dusk to dawn lights http://www.advancetransformer.com/ They make every kind of ballast you would need.
The brightness of projectors isn't measured in lumens of the bulb, it is defined as ANSI-lumens. Thats complete different ! A projected white image is divided into 9 square parts and the brightness of this parts is object of measure. The lumens of bulbs is a general value, which is irrelevant here and can only give rough estimations.
So many older single panel PJs often have MH-bulbs with 575Watts and tens of thousends overall lumens but only 200-300 ANSI lumens !
The rest is blown in the wind.
Hope this clears things up!
xblocker
So many older single panel PJs often have MH-bulbs with 575Watts and tens of thousends overall lumens but only 200-300 ANSI lumens !
The rest is blown in the wind.
Hope this clears things up!
xblocker
More on the 4" LCD...
Marklar if you are interested in the 4", have a look at this one,
http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=205-050&Did=7
good price for what you get...
Also here is another one that might interest you...
http://www3.goldenshop.com.hk/AI-trad/Misc_htm/m_rtft.htm
Nice to see someone is interested in the minimalist(?...er...downsizing) approach.
🙂 😀
Marklar if you are interested in the 4", have a look at this one,
http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=205-050&Did=7
good price for what you get...
Also here is another one that might interest you...
http://www3.goldenshop.com.hk/AI-trad/Misc_htm/m_rtft.htm
Nice to see someone is interested in the minimalist(?...er...downsizing) approach.
🙂 😀
more optical questions
I am still trying to design a lens system to use my 5" lcd in a rear projection scheme. The key parameters are:
* approx distance from lens to screen about 1 to 2m
* Screen size (image size) 1.7m diagonal
I have looked at a few surplus available PCX and DCX lenses, and done some simple calcs and raytracing, and think I need a complex lens system made up of two or more simple thin lenses. I understand that to design a multiple lens system, the image produced from the first lens becomes the object for the second lens. Using simple lens equations you can work out image heights, distances etc. from focal lengths. I wonder can you actually use a virtual image from the first lens (with a negative distance to image) as the object for the second lens?
Does anyone have any experience with designing multiple lens systems to achieve the short throw required?
I am still trying to design a lens system to use my 5" lcd in a rear projection scheme. The key parameters are:
* approx distance from lens to screen about 1 to 2m
* Screen size (image size) 1.7m diagonal
I have looked at a few surplus available PCX and DCX lenses, and done some simple calcs and raytracing, and think I need a complex lens system made up of two or more simple thin lenses. I understand that to design a multiple lens system, the image produced from the first lens becomes the object for the second lens. Using simple lens equations you can work out image heights, distances etc. from focal lengths. I wonder can you actually use a virtual image from the first lens (with a negative distance to image) as the object for the second lens?
Does anyone have any experience with designing multiple lens systems to achieve the short throw required?
[H]ard fan
Yes I visit there daily 😛 i also found some stuff I thought was very nifty that I could put on the white sheet Im useing for a screen.
http://www.goosystems.com/
This sounds like some really cool ****.
Yes I visit there daily 😛 i also found some stuff I thought was very nifty that I could put on the white sheet Im useing for a screen.
http://www.goosystems.com/
This sounds like some really cool ****.
Proxima Controls
Does anyone have or know where to find instructions on operating the control buttons on the 810 or 820? Every time I change the color settings they do not stick, I think i am probably missing some operational knowledge.
Does anyone have or know where to find instructions on operating the control buttons on the 810 or 820? Every time I change the color settings they do not stick, I think i am probably missing some operational knowledge.
there was a whole heap of PDF files on the proxima website of the instruction mauals for those particular panels. i'll have a look for them
edit: i can't find em. i really don't understand it. they are somewhere. i can't be that drunk
edit: i can't find em. i really don't understand it. they are somewhere. i can't be that drunk
Assailant:
Yeah, I am an idiot. Check the website first (duh!). Got the info, thanks...
I have tried many times to navigate that website. It it hard to find something specific. User friendly does not apply.
Yeah, I am an idiot. Check the website first (duh!). Got the info, thanks...
I have tried many times to navigate that website. It it hard to find something specific. User friendly does not apply.
SuperDave:
Without the reflector, I got practically nothing... Thats why i was ready to totally dismiss the MV when I first got it. With the included reflector, i got a bit of a picture, but as you could see from my last pic, I have the bulb vertical, sot the included reflector was mounted on the back wall, and as such was pretty much useless. With the coffee can parabola, brightness increased significantly. Unlike the halogen i used, however, the light kind of fades in with the ambient light when the lens system is out of focus. With the halogen, even out of focus, there was a light spot on the wall. With the MV there are two focus spots, one in which the image is focused, and one in which the filament is focused, but at all other points the light just mixes with ambient light. I think it has to do with the different color temp. So, play with the lens distances. If i move the lens even 1/8", i can lose the pic totally. Last night i built another reflector, a 4 sided, tapered rectangle, kind of like the one built into the halogen worklight. Light leakage was considerably reduced, but even so, the picture was dimmer than with the parabola. The parabola is definatly the way to go. I connected an N64 at about 3 in the morning, and watced as the N64 symbol was about a 2 1/2 square. The picture is almost watchable now, the higher wattage lamp should finalize this deal. BTW, I found a pdf that says an MH can be plugged into an MV ballast, and vice versa, at the expense of some lumens and bulb life.
Without the reflector, I got practically nothing... Thats why i was ready to totally dismiss the MV when I first got it. With the included reflector, i got a bit of a picture, but as you could see from my last pic, I have the bulb vertical, sot the included reflector was mounted on the back wall, and as such was pretty much useless. With the coffee can parabola, brightness increased significantly. Unlike the halogen i used, however, the light kind of fades in with the ambient light when the lens system is out of focus. With the halogen, even out of focus, there was a light spot on the wall. With the MV there are two focus spots, one in which the image is focused, and one in which the filament is focused, but at all other points the light just mixes with ambient light. I think it has to do with the different color temp. So, play with the lens distances. If i move the lens even 1/8", i can lose the pic totally. Last night i built another reflector, a 4 sided, tapered rectangle, kind of like the one built into the halogen worklight. Light leakage was considerably reduced, but even so, the picture was dimmer than with the parabola. The parabola is definatly the way to go. I connected an N64 at about 3 in the morning, and watced as the N64 symbol was about a 2 1/2 square. The picture is almost watchable now, the higher wattage lamp should finalize this deal. BTW, I found a pdf that says an MH can be plugged into an MV ballast, and vice versa, at the expense of some lumens and bulb life.
just found a link that might be of interest:
http://www.uspl.com/uspl_pdf/CRTPAPER.PDF
It's about 5mb.
This white paper from US Precision (now owned by Corning) seems to have lots of general info and I think it also has some optical specs for the delta lenses.
http://www.uspl.com/uspl_pdf/CRTPAPER.PDF
It's about 5mb.
This white paper from US Precision (now owned by Corning) seems to have lots of general info and I think it also has some optical specs for the delta lenses.
Hello again,
I've got no ground breaking news to report. Apart from nobody wants to fix my CRT projector so I'm going to have a go myself. If I don't post anything for the next two months then send somebody round to my flat to poke me with a stick and make sure I've not electrocuted myself in the process...
Wee thought on your bulbs - if you want to avoid a hotspot in the centre of the image say, could you not mirror the end of the bulb? I've stuck a picture of an example - obviously this is a very low power light bulb but the point is, if you mirror the end of it, you're not going to get a bright hotspot in the centre of the picture are you?
Some notes on CRT progress...
I was thinking the other day, how easy it would be to go the LCD route instead. Actually I was thinking "Christ, this is complicated!" I think the CRT route could with time give a better quality picture than the LCD, but it's so much more complicated is it worth it?
Well, since all you guys are doing LCD then somebody's got to investigate CRT, and it's going to be me. I like the idea of having a big three-gun projector like they do in the pubs for big screen footie, instead of an OHP like they do at school. I can see why you all want to hide them away at the back of the room.
Anyway, I have made progress. I have figured out the inside of the TV, and can now compress or stretch the image as much as I like, right down to a tiny dot in the middle of the screen. I can also move the image around the screen and to a certain extent control the geometry of the image. This will prove invaluable for converging the three images at a later stage.
It has to be added that at the moment, controlling the horizontal picture size is a bit of a fire risk. But I just need a ceramic resistor and a heatsink and that'll be sorted out.
One comment on people trying to get a decent image with high ambient light levels...
WHY?! Surely you won't be using it in broad daylight? The whole point of having a large screen is surely to emulate the cinema, is it not? Why would you really need to watch films with the lights on? Or are you planning on doing presentations in your own home?
Can anyone in the UK recommend a cheap OHP to me? I can't find any on ebay. It is for a friend, and it doesn't have to be very high light output at all, as it's just going to be for projecting acetates.
Cheers,
I've got no ground breaking news to report. Apart from nobody wants to fix my CRT projector so I'm going to have a go myself. If I don't post anything for the next two months then send somebody round to my flat to poke me with a stick and make sure I've not electrocuted myself in the process...
Wee thought on your bulbs - if you want to avoid a hotspot in the centre of the image say, could you not mirror the end of the bulb? I've stuck a picture of an example - obviously this is a very low power light bulb but the point is, if you mirror the end of it, you're not going to get a bright hotspot in the centre of the picture are you?
Some notes on CRT progress...
I was thinking the other day, how easy it would be to go the LCD route instead. Actually I was thinking "Christ, this is complicated!" I think the CRT route could with time give a better quality picture than the LCD, but it's so much more complicated is it worth it?
Well, since all you guys are doing LCD then somebody's got to investigate CRT, and it's going to be me. I like the idea of having a big three-gun projector like they do in the pubs for big screen footie, instead of an OHP like they do at school. I can see why you all want to hide them away at the back of the room.
Anyway, I have made progress. I have figured out the inside of the TV, and can now compress or stretch the image as much as I like, right down to a tiny dot in the middle of the screen. I can also move the image around the screen and to a certain extent control the geometry of the image. This will prove invaluable for converging the three images at a later stage.
It has to be added that at the moment, controlling the horizontal picture size is a bit of a fire risk. But I just need a ceramic resistor and a heatsink and that'll be sorted out.
One comment on people trying to get a decent image with high ambient light levels...
WHY?! Surely you won't be using it in broad daylight? The whole point of having a large screen is surely to emulate the cinema, is it not? Why would you really need to watch films with the lights on? Or are you planning on doing presentations in your own home?
Can anyone in the UK recommend a cheap OHP to me? I can't find any on ebay. It is for a friend, and it doesn't have to be very high light output at all, as it's just going to be for projecting acetates.
Cheers,
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