slize said:
hqi, hri, hmi... do these bulbs have the same specs as mh? Especially concerning heat and "being point-source"?
I assume they use specific ballasts?
-> do you mean those are easier to find in Europe?
yes they are, look for aquarium stuff, there you will find hqi lamps. i use a "OSRAM Powerstar HQI-TS 400W/D" with 36000 lumens and a bulb life of 9000h (manufactor)
Hey thanks! Thats some great info!
I hope I'll find one of those around here but i think it should be no problem because there is a very big aquarium shop in the neighbourhood here...
I'll stop by this afternoon and let you know if i find anything
I hope I'll find one of those around here but i think it should be no problem because there is a very big aquarium shop in the neighbourhood here...
I'll stop by this afternoon and let you know if i find anything
Great declined, i live in Holland and also looking for bulbs an balasts, so keep us posted.
Maybe you can tell me also the name of the shop, so i can visit them also, if you have good results.
What are the specs of youre diy projector?
greets
Maybe you can tell me also the name of the shop, so i can visit them also, if you have good results.
What are the specs of youre diy projector?
greets
slize said:
You don't need a new fresnel with longer focal point if you just move the bulb closer to the fresnel and the fresnel will project the light further towards your projection lens + eyeglass combo. Some OHP's have a such adjustment for the bulp assembly, I think. Obviously a longer FL fresnels helps, but on the other hand the closer distance between bulp and fresnel may in fact make the image brighter, though if it's too close to the fresnel the angle between fresnel and light ray's may become too big and some of the light will be reflected away making the picture dim in corners. I think about 8" is the closest distance* between bulb and fresnel which you can use. If you take the bulb further then you better use a condencer lens.
*) for 15" LCD or about 12"x12" fresnel
Brainchild,
Just want to confirm once you added the dioptrin lens you were getting a sharp even image with brightness and everything edge to edge?
What diameter is your dioptrin? What diameter is objective projection lens?
Just want to confirm once you added the dioptrin lens you were getting a sharp even image with brightness and everything edge to edge?
What diameter is your dioptrin? What diameter is objective projection lens?
Brainchild,
"So I grab my objective and put it 8"-10" farther out from the hole in my box"
Your beamer looks pretty long already. How long would it be if you added the extra 10 inches between second fresnel and objective/dioptrin combo?
"So I grab my objective and put it 8"-10" farther out from the hole in my box"
Your beamer looks pretty long already. How long would it be if you added the extra 10 inches between second fresnel and objective/dioptrin combo?
I know a litle bit concepts about building this projector. but the big problem is that I cannot find the LCD panel like Sharp QA-1800 in my country (surakarta, Indonesia). So I think to find any alternative panel like tv-lcd portable (Casio tv mobil for example). But the most problem is replacement the panel from its cabinet.
Can anybody here help me to do this ? or tell me other alternative
with this !
Thank You
Can anybody here help me to do this ? or tell me other alternative
with this !
Thank You
I am being told that the maximum diameter eyeglass lens you can get anywhere is 65mm.
Brainchild Is this what you are also did the test with? Is your Projection lens not 80mm? No image cropping?
Brainchild Is this what you are also did the test with? Is your Projection lens not 80mm? No image cropping?
Ok... once again I didn't get the info from the aquarium shop because the owner wasn't there that day and his son didn't know anything about the bulbs-> monday I'll go back and ask the owner himself...
finally
i gave up!!! this picture thing doesn't work for me... 😡 i decided to built my projector as light as i can and to put it onto the ceiling at the distance i need... damn calculations, they were right, but they weren't practical. next friday i'll make a vid night and i need the damn projector so i'll decided to give up on the calculations... sry @ all...
i gave up!!! this picture thing doesn't work for me... 😡 i decided to built my projector as light as i can and to put it onto the ceiling at the distance i need... damn calculations, they were right, but they weren't practical. next friday i'll make a vid night and i need the damn projector so i'll decided to give up on the calculations... sry @ all...
Cheap MH lamps
Hello there!
I'm a long time lurcher (since thread 1).
Just got back here to check things out.
There's been great progress!
Anyway, for you dutch guys looking for cheap MH lamps, they can be found in the nearest canna-growshop...
Smokeys are cheap.
I know that the rest of their gear is not what would be called morally correct where I live, but who really cares?
😉
Good luck guys!
Hello there!
I'm a long time lurcher (since thread 1).
Just got back here to check things out.
There's been great progress!
Anyway, for you dutch guys looking for cheap MH lamps, they can be found in the nearest canna-growshop...
Smokeys are cheap.
I know that the rest of their gear is not what would be called morally correct where I live, but who really cares?
😉
Good luck guys!
Re: finally
Yes, the keystone correction with the condencing fresnel (the one between TFT and pj lens) works pretty well.
Btw. It's a must for anyone using dismantled monitor to split the OHP fresnel (or use two single). Also anyone with OHP and dismantled TFT monitor should do the same. Propably the pj panels use different LCD panels, but at least with my BenQ FP567s (same panel as in FP557s) the condenced light (from usual double fresnel) makes the picture unevenly light, distorted in colors and dim. This is because the contrast in TFT is best with collimated light source, the light which hits the panel in other than 90 degrees angle just spoils the picture.
slize said:
Yes, the keystone correction with the condencing fresnel (the one between TFT and pj lens) works pretty well.
Btw. It's a must for anyone using dismantled monitor to split the OHP fresnel (or use two single). Also anyone with OHP and dismantled TFT monitor should do the same. Propably the pj panels use different LCD panels, but at least with my BenQ FP567s (same panel as in FP557s) the condenced light (from usual double fresnel) makes the picture unevenly light, distorted in colors and dim. This is because the contrast in TFT is best with collimated light source, the light which hits the panel in other than 90 degrees angle just spoils the picture.
The proven design
There is now at least one proven design that works for building a DIY projector with excellent results:
1. Use a dismantled TFT monitor (approved list of monitors: CMV1515, 1512, BenQ FP557s or FP567s) as the panel and controller. You'll get the native XGA resolution with a good contrast (500:1) and good colors (look for real 24-bit color, though the 18-bit 'dithered 16.2 million' will work almost as well).
2. Use a 'split OHP fresnel' or two single sided fresnels, one for collimation (between the lamp and the panel) and the other for condencing (between the panel and pj lens/mirror).
3. Keystone correction can be done by tilting the condencer fresnel.
4. The pj can be mounted on the floor or onto the ceiling so it's out of way.
5. You can buy the fresnel and the triplet lens from diylabs.org
6. Use a 250W HQI double ended metal halide lamp (like OSRAM) with color temperature of 4200 K or 5200 K. If you use the condencer lens you can use 150W CMD lamp (like Philips) which have better CRI (color rendering index) than the 250W HQI.
7. Use a reflector behind the lamp, it has to be spherical, nothing else works! For and example a soup laddle works well if it's (almost) perfectly round.
8. Optional: Use a concencer lens on top of the lamp with a large diameter (~80 mm) and short (~100 mm) focal length.
9. Optional: Use mirror to mirror the image before pj lens or after it. Closer to the pl lens it is the smaller can it be. If you don't use mirror you must be able to mirror the image by using the TFT 'wrong way' - not recommended as the TFT may have a transreflective polarisation filter on it's l'ight source side' but not on the 'viewing side'.
10. Mandatory: Use cooling for the lamp and the panel. Four regular 80 mm fans are enough (two blow in, two out) , maybe two that just suck the air out from the box.
Ok, that's it, get the parts and build the projector. Now let's see who's got the simplest design pj that's built after all these 'rules'.
Btw. We should now write sections on how to dismantle the monitor and how to split the fresnel, right? Also some good technical drawnings were useful (with mirror, without mirror, for ceiling mounting or for a floorstander). Also good photos on different technical solutions for TFT and fresnel mounting, cooling etc.
There is now at least one proven design that works for building a DIY projector with excellent results:
1. Use a dismantled TFT monitor (approved list of monitors: CMV1515, 1512, BenQ FP557s or FP567s) as the panel and controller. You'll get the native XGA resolution with a good contrast (500:1) and good colors (look for real 24-bit color, though the 18-bit 'dithered 16.2 million' will work almost as well).
2. Use a 'split OHP fresnel' or two single sided fresnels, one for collimation (between the lamp and the panel) and the other for condencing (between the panel and pj lens/mirror).
3. Keystone correction can be done by tilting the condencer fresnel.
4. The pj can be mounted on the floor or onto the ceiling so it's out of way.
5. You can buy the fresnel and the triplet lens from diylabs.org
6. Use a 250W HQI double ended metal halide lamp (like OSRAM) with color temperature of 4200 K or 5200 K. If you use the condencer lens you can use 150W CMD lamp (like Philips) which have better CRI (color rendering index) than the 250W HQI.
7. Use a reflector behind the lamp, it has to be spherical, nothing else works! For and example a soup laddle works well if it's (almost) perfectly round.
8. Optional: Use a concencer lens on top of the lamp with a large diameter (~80 mm) and short (~100 mm) focal length.
9. Optional: Use mirror to mirror the image before pj lens or after it. Closer to the pl lens it is the smaller can it be. If you don't use mirror you must be able to mirror the image by using the TFT 'wrong way' - not recommended as the TFT may have a transreflective polarisation filter on it's l'ight source side' but not on the 'viewing side'.
10. Mandatory: Use cooling for the lamp and the panel. Four regular 80 mm fans are enough (two blow in, two out) , maybe two that just suck the air out from the box.
Ok, that's it, get the parts and build the projector. Now let's see who's got the simplest design pj that's built after all these 'rules'.
Btw. We should now write sections on how to dismantle the monitor and how to split the fresnel, right? Also some good technical drawnings were useful (with mirror, without mirror, for ceiling mounting or for a floorstander). Also good photos on different technical solutions for TFT and fresnel mounting, cooling etc.
I want to build my beamer and later add a condenser when available from diylabs. Will things have to move and will the box have to be longer or shorter?
dracul said:
Only software solution that works (with HTPC) to mirror the image is Dscaler. It can't play DVD's and DivX (correct me if I'm wrong, maybe it can?). Also there might be a codec (like DivX codec or any other codec) that mirrors the image (www.montivison.com, MV Mirror Directshow filter costs 49 EUR +VAT btw.) , so with a software that lets you manually connect the WDM filters to 'build the graph' (Zoom Player?) you could also watch DVD's or DivX.
With condencer lens (or any other lens) the inversion of total focal length is the sum of the inversion of the two other focal lengths. So practically 'things have to move' closer to the fresnel.
This is the first time I am hearing that you need to mirror the image. So with no mirror physical or software I will have an upside down image correct?
Didnt Brainchild build his beamer without any mirrors? I dont remeber him mentioning anything about this problem....
Didnt Brainchild build his beamer without any mirrors? I dont remeber him mentioning anything about this problem....