Hello all!!
I have read a lot about DIY Projectors mostly from this website and decided a couple of weeks back that i should get my hands dirty and finally took the plunge.
Let me get right to the point ,
here is a list of components i have used
LCD -Acer 15.6" X163wb (1366x768,500:1,8ms)
Osram 400watt MH Lamp(pic shown below),parabolic reflector made from ss steel
400w Magnetic core ballast
220mm collimator fresnel ,330mm collector fresnel(bought from 3dlens.com)
projection triplet 72mm dia 317mmfl (bought from a local source)
tempered glass
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Fresnels,lamp and LCD (with frames)
Full Version: my 15.6" 720p pj
The design is the simplest one ie the straight through design with the box type enclosure.i have used a PVC pipe for the focusing mechanism as can be seen in the picture below
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Inside the Projector
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Inside the Projector
i have been able to get the projection but the only problem seems to be the brightness.The really bright scenes in a movie(ie the daytime scenes) are visible but the dark scenes are almost impossible to watch.i have included a picture of the lamp with the reflector below
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lamp and reflector
is the reflector good enough?
the anti glare has not been removed from the LCD could this be the problem??any help is appreciated.
i have tried moving the lamp as well as the lenses to various positions but has not helped much.
i will be including pictures of the projected image as well as the concentration of light around the triplet soon.
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lamp and reflector
is the reflector good enough?
the anti glare has not been removed from the LCD could this be the problem??any help is appreciated.
i have tried moving the lamp as well as the lenses to various positions but has not helped much.
i will be including pictures of the projected image as well as the concentration of light around the triplet soon.
here are some pics of the projections obtained and the light concentration around the triplet
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another pic along with laptop image
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light around the triplet
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use the reflector and condensor lens and you will see huge increase in brightness. I did.
Try removing the huge reflector you have in there and see if the image improves.
QUOTE (Quasi_Mojo @ Jul 18 2009, 09:19 AM) 
Try removing the huge reflector you have in there and see if the image improves.
actually the image improved a little after using the reflector but maybe the pro reflector will make a difference, anyway should i try stripping the ag before spending more on the reflector and the condenser?
anyway i thought i should try the ag strip before spending more money on the reflector and the condenser lens.
here is the procedure i am following
1)laid down a towel over which i placed the lcd.
2)used transparent plastic wrap to cover the ffc and electronics.
3)laid down 3 layers of paper towel and poured water over it.
started the process abour 40min back.
will probably try to remove the layer in abt 4hrs time so if anybody has any advice now will be the time!!
pic of what i have explained above
Click to view attachment
here is the procedure i am following
1)laid down a towel over which i placed the lcd.
2)used transparent plastic wrap to cover the ffc and electronics.
3)laid down 3 layers of paper towel and poured water over it.
started the process abour 40min back.
will probably try to remove the layer in abt 4hrs time so if anybody has any advice now will be the time!!
pic of what i have explained above
Click to view attachment
even with the ag on ,
with a 400w lamp in there you should have a much brighter image .
the ag removal makes a difference , but not a huge one. imo
a reflector and precon will make a much bigger difference
put a piece of cardboard in front of the triplet lense and see where the light is coming to a point
should be in the center of the lense and also it should not be bigger than the lense or too small a point
the reason i say this is, it looks like you have some light going over the top of the triplett
with a 400w lamp in there you should have a much brighter image .
the ag removal makes a difference , but not a huge one. imo
a reflector and precon will make a much bigger difference
put a piece of cardboard in front of the triplet lense and see where the light is coming to a point
should be in the center of the lense and also it should not be bigger than the lense or too small a point
the reason i say this is, it looks like you have some light going over the top of the triplett
heres what happened in the last 24 hrs
i tried removing the ag after abt 6hrs but pulled the polarizer instead, not entirely but just a corner abt 1cm by 1cm.left the paper towels on for another 18hrs and tried again but couldn't remove the ag so i finally decided to rip both the ag and the polarizer which was easier ,it came out in one piece.will include pics soon.im going to try and order the polarizer from 3dlens.com it ships for abt 27$ but ill prob try to look for a local source first.
i decided to do this after reading some posts on the availability of polarizers with good transmittance.
i tried removing the ag after abt 6hrs but pulled the polarizer instead, not entirely but just a corner abt 1cm by 1cm.left the paper towels on for another 18hrs and tried again but couldn't remove the ag so i finally decided to rip both the ag and the polarizer which was easier ,it came out in one piece.will include pics soon.im going to try and order the polarizer from 3dlens.com it ships for abt 27$ but ill prob try to look for a local source first.
i decided to do this after reading some posts on the availability of polarizers with good transmittance.
will the pro reflector work with my mh lamp?
yes
should i get the ikea napkin holder or the pro reflector?cus ive read that the pro reflector does not have a good service life and that with certain lamps the ikea napkin holder works better.
That is pretty dim.
1) Sure the ballast/lamp is working properly? Clamp on Meter maybe?
2) Sure your measurements are right? Do they plug into the focal calc correctly?
3) Is everything centered between the center of the arc and the triplet?
1) Sure the ballast/lamp is working properly? Clamp on Meter maybe?
2) Sure your measurements are right? Do they plug into the focal calc correctly?
3) Is everything centered between the center of the arc and the triplet?
QUOTE (parawizard @ Jul 23 2009, 06:25 PM)
That is pretty dim.
1) Sure the ballast/lamp is working properly? Clamp on Meter maybe?
2) Sure your measurements are right? Do they plug into the focal calc correctly?
3) Is everything centered between the center of the arc and the triplet?
1) Sure the ballast/lamp is working properly? Clamp on Meter maybe?
2) Sure your measurements are right? Do they plug into the focal calc correctly?
3) Is everything centered between the center of the arc and the triplet?
1)yes, im guessing so cus the bulb seems to be working fine.is there anyway i can check if im using the full capacity of the bulb?(what is clamp on meter?)
2)I have not used it after my initial calculations and have not found the need to do so since i know the focal length of each of the lenses,the distance between the various components are as shown in one of the pictures above, please let me know if there are any errors(i am using 220/330mm fl lens and 317mm triplet.)
3)yes i can clearly see the image of the arc when the LCD removed.
QUOTE (krishnarangan @ Jul 17 2009, 10:19 AM)
light around the triplet
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You may try cutting back the pvc around the triplet. It looks like it is blocking some of the FOV of the triplet. Also even though you measured right it does not mean the fresnel is exactly 220mm. Probably it has a tolerance and you may see improvement just by moving the light away from the fresnel by 1/4 to 1/2 inch and get more of the light in the triplet.
Also I bought my fresnel, which is a 3D lens 330mm, and it does not align center. It's focus is off center by about 1.5" at the focal point. So some of the issue may also be from having the same bad lens as I do.
Try removing the triplet from the PVC housing and hold it by hand at the correct distance. Part of the problem might be that the PVC is blocking some of the light from hitting the triplet, as InlineTwin pointed out.
The rear fresnel has a focal length of 220mm, so the center of the lamp's arc chamber should be about 220mm from the rear fresnel. You'll probably find that you'll get more brightness by moving the lamp about 10mm closer to the rear fresnel.
You don't say how large your desired projected image is, or what your throw is, but you can see by the FocalCalc images below how the LCD Distance (from LCD to focal center of triplet) and Screen Distance (throw) changes for different sized projected images.
This one shows a 90" diagonal image at a throw of about 6.7 feet:
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And this image shows a 120" diagonal image at a throw of about 8.5 feet:
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The rear fresnel has a focal length of 220mm, so the center of the lamp's arc chamber should be about 220mm from the rear fresnel. You'll probably find that you'll get more brightness by moving the lamp about 10mm closer to the rear fresnel.
You don't say how large your desired projected image is, or what your throw is, but you can see by the FocalCalc images below how the LCD Distance (from LCD to focal center of triplet) and Screen Distance (throw) changes for different sized projected images.
This one shows a 90" diagonal image at a throw of about 6.7 feet:
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And this image shows a 120" diagonal image at a throw of about 8.5 feet:
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put a piece of cardboard in front of the triplet and take a pic
it will show where your light is going
and like quasi said take the pvc off
it will show where your light is going
and like quasi said take the pvc off
I was just going to add that. 
QUOTE (Quasi_Mojo @ Mar 3 2009, 04:26 PM)
You might want to tape a piece of paper over the inside of the triplet like this:
Yeah, I think I said remove the pvc...but regardless it seems there is more light outside the triplet than desired as viewed from the pic, so moving the light is a start....as I also said.
thanks for all your help. i took some of you suggestions, and here is what i have done so far,
1)i removed the large reflector and have ordered the pro reflector.
2)removed the pvc pipe and taped a piece of cardboard over the triplet.
3)moved the collimator Fresnel towards the lamp(the distance between the lamp and the fresnel is now 210mm)
4)rechecked my calculations using the focal calc and everything seems to be fine.
here is a picture of the light blob on the cardboard
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picture from the opposite side(from outside the box)
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light around the triplet
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in the 3rd picture it doesn't look like there is much light around the triplet but the actual light around the triplet is more.
1)i removed the large reflector and have ordered the pro reflector.
2)removed the pvc pipe and taped a piece of cardboard over the triplet.
3)moved the collimator Fresnel towards the lamp(the distance between the lamp and the fresnel is now 210mm)
4)rechecked my calculations using the focal calc and everything seems to be fine.
here is a picture of the light blob on the cardboard
Click to view attachment
picture from the opposite side(from outside the box)
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light around the triplet
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in the 3rd picture it doesn't look like there is much light around the triplet but the actual light around the triplet is more.
looks very good
has your brightness improved ?
post a new screenie
has your brightness improved ?
post a new screenie
QUOTE (jeffek @ Jul 26 2009, 10:28 PM)
looks very good
has your brightness improved ?
post a new screenie
has your brightness improved ?
post a new screenie
no still remains the same.i also changed the gamma settings from 1.0 to 1.5 so the picture is brighter but there is a lot of loss of detail, and still is not bright enough.do you think the pro reflector will make a difference(as of now im not using any reflector as i have removed the large one.)
here is a screenie you requested(im using the polarizer i removed so there are a lot of marks on the projected image.i have ordered the pf006 polarizer from polarization.com and will post pics after i get that,but that could be a while)
Click to view attachment
absolutely ,
going from no reflector at all to the pro reflector will make a huge difference
at least until your new polorizer gets there , you know that all your optics are aligned properly
....waiting with anticipation
going from no reflector at all to the pro reflector will make a huge difference
at least until your new polorizer gets there , you know that all your optics are aligned properly
....waiting with anticipation
QUOTE (jeffek @ Jul 27 2009, 12:33 AM)
absolutely ,
going from no reflector at all to the pro reflector will make a huge difference
at least until your new polorizer gets there , you know that all your optics are aligned properly
....waiting with anticipation
going from no reflector at all to the pro reflector will make a huge difference
at least until your new polorizer gets there , you know that all your optics are aligned properly
....waiting with anticipation
thanks a lot man,i am getting both the reflector and the polarizer on 16th aug so its going to be a very painfully long wait.
I noticed up above you said you did an AG strip. Do both sides of the LCD now look like a black highly reflective surface?
Can you take a picture of the triplet side of the LCD with the light engine one and the back part of the projector covered? Or can you verify that the picture on the LCD is bright and clear?
Have you tried projecting without the tempered glass in place?
Can you take a picture of the triplet side of the LCD with the light engine one and the back part of the projector covered? Or can you verify that the picture on the LCD is bright and clear?
Have you tried projecting without the tempered glass in place?
QUOTE (Quasi_Mojo @ Jul 28 2009, 06:21 AM)
I noticed up above you said you did an AG strip. Do both sides of the LCD now look like a black highly reflective surface?
Can you take a picture of the triplet side of the LCD with the light engine one and the back part of the projector covered? Or can you verify that the picture on the LCD is bright and clear?
Have you tried projecting without the tempered glass in place?
Can you take a picture of the triplet side of the LCD with the light engine one and the back part of the projector covered? Or can you verify that the picture on the LCD is bright and clear?
Have you tried projecting without the tempered glass in place?
thats right i idid an ag strip but the ag layer didnt come off even after abt 30hrs so i decided to pull the polarizer.i am currently using the polarizer that i stripped(finally after submerging the polarizer in a bucket of water for abot 48hrs i was able to remove the ag in a large number of pieces).i have ordered the pf006 polarizer from polarization.com it should be here in a couple of weeks.the picture on the lcd is very bright and clear.i have also ordered the pro reflector(i am currently not using any reflector as i removed the large parabolic one as suggested).will include pictures of the triplet side of the LCD soon.
im thinking about using a precondensor lens but im not sure about the dimensions that is required for my setup.
im using a 220mm/330mm fresnels, and a 60mm(clear aperture) 317fl triplet.i tried using the precondensor calculator and here is what i get
Pre-condenser
(n-1)*fl =Radius= 78.447 mm
Marginal BFL= 116.9888949 mm
Marginal Ray Angle = 25.61106551 deg
do these numbers look right?
if not please let me know the correct dimensions.
im using a 220mm/330mm fresnels, and a 60mm(clear aperture) 317fl triplet.i tried using the precondensor calculator and here is what i get
Pre-condenser
(n-1)*fl =Radius= 78.447 mm
Marginal BFL= 116.9888949 mm
Marginal Ray Angle = 25.61106551 deg
do these numbers look right?
if not please let me know the correct dimensions.
QUOTE (Quasi_Mojo @ Jul 27 2009, 06:51 PM)
... Do both sides of the LCD now look like a black highly reflective surface?
...
Have you tried projecting without the tempered glass in place?
...
Have you tried projecting without the tempered glass in place?
What I was getting at with the first question was that on a lot of LCD panels, there is a reflective layer on the backlight side of the LCD that helps reflect the light back to the viewer. If your LCD has that reflective layer, then it might be blocking some of the light from passing through the LCD.
Check out these threads to give you an idea of what you might be facing: Help me to decide to strip my 10.6" LCD
And maybe philw's PLOG.
And again, have you tried projecting without the tempered glass in place?
QUOTE (Quasi_Mojo @ Aug 13 2009, 06:32 PM)
What I was getting at with the first question was that on a lot of LCD panels, there is a reflective layer on the backlight side of the LCD that helps reflect the light back to the viewer. If your LCD has that reflective layer, then it might be blocking some of the light from passing through the LCD.
Check out these threads to give you an idea of what you might be facing: Help me to decide to strip my 10.6" LCD
And maybe philw's PLOG.
And again, have you tried projecting without the tempered glass in place?
Check out these threads to give you an idea of what you might be facing: Help me to decide to strip my 10.6" LCD
And maybe philw's PLOG.
And again, have you tried projecting without the tempered glass in place?
thanks for your help.i read the above threads but i am not facing the same problem.the rear of my lcd doesn't have a mirror like reflective layer, all it has is a shiny polarizer,any way i should be getting my pro reflector in a couple of days thought ill try that out and post more info.in the mean time can you tell me the specification of the condenser lens required for my pj.
thanks in advance.
ps i have tried removing the tempered glass and it doesn't help.
just received and mounted the polarizer and pro reflector couple of days back, but the brightness still isnt upto my satisfaction.i will include pics soon,prob in a couple of hours.if anybody has any ideas to increase brightness please let me know.
i finally got the projector running with a satisfactory brightness,although the brightness of the projector is the same, with a few modifications on the lcd and the laptop i was able to get a rich bright picture.
i turned up the gamma settings on the laptop to 1.8 and this lead to the image being bright but with a lot of loss in color detail,so i changed the color settings on the lcd to "user" mode with the following level for rgb
Red-50
Green-35
Blue-55
and the contrast is at 60
although i reduced the green and increased the blue levels, the greens and reds are rich but the blues seem to be a little on the green side(cant make the difference unless i look at the laptop and projection side by side.).I am using a 5600k lamp and a light green wall as projection surface maybe that makes the difference??
Any way i am satisfied with the results, but i wish i could have gotten the same results without changing the gamma settings on the laptop!!
any suggestions are welcome.
i have posted some screen shots below.The pictures are much better(colour/contrast) in real.
some pics from transformer 2
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i turned up the gamma settings on the laptop to 1.8 and this lead to the image being bright but with a lot of loss in color detail,so i changed the color settings on the lcd to "user" mode with the following level for rgb
Red-50
Green-35
Blue-55
and the contrast is at 60
although i reduced the green and increased the blue levels, the greens and reds are rich but the blues seem to be a little on the green side(cant make the difference unless i look at the laptop and projection side by side.).I am using a 5600k lamp and a light green wall as projection surface maybe that makes the difference??
Any way i am satisfied with the results, but i wish i could have gotten the same results without changing the gamma settings on the laptop!!
any suggestions are welcome.
i have posted some screen shots below.The pictures are much better(colour/contrast) in real.
some pics from transformer 2
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Click to view attachment
Click to view attachment
thats all for now.
i thought of using a condenser lens, but am not sure of the dia and focal length that i have to use with my setup.any help is appreciated.
thats all for now.
i thought of using a condenser lens, but am not sure of the dia and focal length that i have to use with my setup.any help is appreciated.
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