Full Version: My First Projector 1080p
Ok so I've been looking into this whole diy projector thing pretty closely now and have made up my own plans for the projector. I'm planning on using mostly parts from lumenlab as far as optics. I was thinking: pro-triplet, pro-condenser, pro-field, and the lumenlab LL65K T15 lamp kit. I'm going to get a 1080p 15.4" lcd from ebay and the G2A board from that CA guy. I'm planning on making my own reflector and I have a good idea for my cooling solution. I'm planning on adding a pre-condenser lens but I'm going to get my projector working normally first, and then add the extra lens later. I've made a 3D model of the projector in google SketchUp and I wanted to know if somebody could take a look at it and let me know if my measurements seem correct. Just as a side note, the extra rectangle inbetween the two fresnels is the virtual LCD image created by the field fresnel lens. I'll sum up my measurements in words for those of you that don't have sketchup. The lamp is exactly 220mm away from the condenser, the LCD is 15mm from the condenser and the field is 20mm away from the LCD. I wasn't exactly sure what the distance from the field and condenser to the LCD should be, I just reffered to the simple projector plans in the forums. From the 3D model, I figured that the end of the triplet, 560mm away from the LCD filled enough of the triplet lens without the image getting too close to the edge of the lens. Then, through the formula 1/f=1/di+1/do (f=focal length, di=image distance from triplet vertical plane, do=virtual LCD image distance from triplet vertical plane), I figured that about 3258mm away from the vertical plane of the triplet I should get an image of about 1898mm across and about 1225mm down. The size of the LCD is 344mm across and 222mm down. Could anybody tell me if these numbers sound correct or am I off somewhere? Also, any recomendations or hints before I go off and spend 1500$ would be greatly appreciated. Thanks in advance. Apperently I can't upload the sketchup file cause its not an allowed file extension so if anybody wants to see the 3D model let me know and I'll email it to you.
Welcome to PJ building 
First of all, this is how I post sketchup pictures here. There is probably a better way, but I do a 'print screen' of the model, past it into microsoft paint, then box and copy the portion of the screen I actually want to show (ie without the sketchup tool bars etc) and paste that into a new paint picture, save that as a JPEG, resize the image to less than 100K (I use Microsoft's resizer) and the whack it in as a file attachment to my post .
Your collimator / LCD / field distances seem ok for a split design from what I've read, but as I am doing an unsplit I can't specifially help you. But for a straight forward design, as long as the airgap between the collimator and LCD is at least 13mm, and the gap to the field is far enough so you don't get its rings in your image, you should be well in the ballpark. The key is to build in as much adjustablilty as you can, because ballparks are good, but tweaking everything once it's running is what this game is about.
If the lamp is exactly 220mm from the collimator, many people report seeing a 'hotspot' in the centre of their projected image, and it being dull away from the centre. Moving the lamp forward a bit can assist. I put my lamp at 210mm initially, and the picutre looks great and no hotspotting. Some have gone as close as 205. Your perfect position will also be found in the tweaking.
In terms of the distance to the triplet, use the Focal Calculator - you should find it as a sticky in the beginner's forum or the tools section. I know it's there somewhere. Also have a look at Ozstang65's thread 'Help us help you' I think it's called, if you haven't already. You might also want to look at Durachko's tweaking guide before you start to build. It really helped me get my head around the need for putting adjustability into my PJ, and just a much better understanding of what I was trying to achieve.
All the best with your build.
First of all, this is how I post sketchup pictures here. There is probably a better way, but I do a 'print screen' of the model, past it into microsoft paint, then box and copy the portion of the screen I actually want to show (ie without the sketchup tool bars etc) and paste that into a new paint picture, save that as a JPEG, resize the image to less than 100K (I use Microsoft's resizer) and the whack it in as a file attachment to my post .
Your collimator / LCD / field distances seem ok for a split design from what I've read, but as I am doing an unsplit I can't specifially help you. But for a straight forward design, as long as the airgap between the collimator and LCD is at least 13mm, and the gap to the field is far enough so you don't get its rings in your image, you should be well in the ballpark. The key is to build in as much adjustablilty as you can, because ballparks are good, but tweaking everything once it's running is what this game is about.
If the lamp is exactly 220mm from the collimator, many people report seeing a 'hotspot' in the centre of their projected image, and it being dull away from the centre. Moving the lamp forward a bit can assist. I put my lamp at 210mm initially, and the picutre looks great and no hotspotting. Some have gone as close as 205. Your perfect position will also be found in the tweaking.
In terms of the distance to the triplet, use the Focal Calculator - you should find it as a sticky in the beginner's forum or the tools section. I know it's there somewhere. Also have a look at Ozstang65's thread 'Help us help you' I think it's called, if you haven't already. You might also want to look at Durachko's tweaking guide before you start to build. It really helped me get my head around the need for putting adjustability into my PJ, and just a much better understanding of what I was trying to achieve.
All the best with your build.
QUOTE (Lola T70 MkIII @ Feb 1 2007, 04:27 AM) 
Welcome to PJ building
First of all, this is how I post sketchup pictures here. There is probably a better way, but I do a 'print screen' of the model, past it into microsoft paint, then box and copy the portion of the screen I actually want to show (ie without the sketchup tool bars etc) and paste that into a new paint picture, save that as a JPEG, resize the image to less than 100K (I use Microsoft's resizer) and the whack it in as a file attachment to my post .
First of all, this is how I post sketchup pictures here. There is probably a better way, but I do a 'print screen' of the model, past it into microsoft paint, then box and copy the portion of the screen I actually want to show (ie without the sketchup tool bars etc) and paste that into a new paint picture, save that as a JPEG, resize the image to less than 100K (I use Microsoft's resizer) and the whack it in as a file attachment to my post .
Hi,
Sketchup is a great tool. I don't know if my version is different than yours but this might save you a few steps. I go to ==> file ==> export ==> 2d graphic. Then in the save as dialogue box, I pick png because it supports transparency. I can then scale the image in another program and no background shows and there are no title or tool bars.
QUOTE (AZ_SwimCoach @ Mar 14 2007, 10:11 AM)
Hi,
Sketchup is a great tool. I don't know if my version is different than yours but this might save you a few steps. I go to ==> file ==> export ==> 2d graphic. Then in the save as dialogue box, I pick png because it supports transparency. I can then scale the image in another program and no background shows and there are no title or tool bars.
Sketchup is a great tool. I don't know if my version is different than yours but this might save you a few steps. I go to ==> file ==> export ==> 2d graphic. Then in the save as dialogue box, I pick png because it supports transparency. I can then scale the image in another program and no background shows and there are no title or tool bars.
Thanks, coach - that sounds like a great idea. I haven't actually been back to use sketchup since about my last post on this thread, but when I do I'll give it a go.
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