Hi everyone. This is a great place to gather info for diy projectors. I have been reading for the last couples of weeks now. I am planning to build my own projector. I already bought and stripped down a 15" Benq fp 557s, very easily and tried in onto a OHP, a PORTA-Scribe g-100. The results were not so good, and very yellowish. Of course, i was using a bed sheet, so that can't be too good.
Nevertheless, I am planning on building a projector that would work with thoses specs: 10 foot screen, 10 foot throw distance (lens to screen).
Should I go with the lumenlab lens kit, or there are other options?
How about the varifocal lens that has a focal lenght of about 225mm that is sold a diyprojectorcompany.com? And the triplet 135 , long throw lens, do I need that, and would it make a difference in terms of image quality?
I calculated that I needed something of around 330mm.
In terms of lighting, what is the main reason to go with a 400 watts Metal Halide as opposed to a 250 watts one?
Do the fresnels have to be the same size of the lcd screen? (15" in my case)
I think that is enough questions for now..
Thanks a lot
Nevertheless, I am planning on building a projector that would work with thoses specs: 10 foot screen, 10 foot throw distance (lens to screen).
Should I go with the lumenlab lens kit, or there are other options?
How about the varifocal lens that has a focal lenght of about 225mm that is sold a diyprojectorcompany.com? And the triplet 135 , long throw lens, do I need that, and would it make a difference in terms of image quality?
I calculated that I needed something of around 330mm.
In terms of lighting, what is the main reason to go with a 400 watts Metal Halide as opposed to a 250 watts one?
Do the fresnels have to be the same size of the lcd screen? (15" in my case)
I think that is enough questions for now..
Thanks a lot
If you want a 10ft screen from 10ft away then you want a throw ratio of 1:1 ....
which means all the standard lens kits will do that .... no need to get the larger long throw triplets .....
Also, when dealing with a 15" Id recomend nothing but a 400W MH .... 250W just isnt bright enough, and isnt that much of a cost difference to justify using it over a 400W.
I personally went with the lumenlab site, because they have many many more results and activity at their boards
The lumenlab kit will include a split fresnel design and both fresnels are large enough to completly cover a 15" LCD.
You can check my lumenlab results in this forum .....
which means all the standard lens kits will do that .... no need to get the larger long throw triplets .....
Also, when dealing with a 15" Id recomend nothing but a 400W MH .... 250W just isnt bright enough, and isnt that much of a cost difference to justify using it over a 400W.
I personally went with the lumenlab site, because they have many many more results and activity at their boards
The lumenlab kit will include a split fresnel design and both fresnels are large enough to completly cover a 15" LCD.
You can check my lumenlab results in this forum .....
Scubasteve2365 said:
I would disagree - I've seen many projects with a 15" LCD and 250w bulbs that are plenty bright - some here and many of them at the french site, allinbox. Your required wattage is more a function of your desired projected image size and efficiency of your light engine. In fact,
here is a 15" w/150watt CDMT bulb that looks nice and bright to me. Ace has posted that he's seen an output as good or better than a 250watt HQI (with a spherical reflector and condensor) from a 150watt CDM-T bulb with an ellipsoidal reflector. Personally I'd rather go with a more efficient lower wattage setup so I burn less electricity and generate substantially less heat to remove from the projector.
Ok, it's more of a matter of light efficiency, and I guess, one would have to user both a reflector and a condensor along with a 250 watts metal halide in order to get good results.
What is the same items were used with a 400 watts ? Would that work and how good would the output be?
I guess that the projector using a 400 watts bulb do not have a reflector.
Can anybody comment on my previous other questions??
What is the same items were used with a 400 watts ? Would that work and how good would the output be?
I guess that the projector using a 400 watts bulb do not have a reflector.
Can anybody comment on my previous other questions??
jfguay2 said:
The LL kit is fine for what you want or the standard 80mm triplet and fresnel from DIY Projector Company is fine too.
Given a 15" LCD. the 225mm lens would require a shorter throw distance for the image size you want, the long throw would require a longer throw distance. For your 10ft screen at 10ft distance stick with the 320 or 330mm triplet lenses.
Yes - or larger if you intend to use the fresnel for keystone correction. And just as a note - I've seen 400W light setups with a relector. Just look through the galleries here, at the LL forum, and at Allinbox to see some nice and inspiring results.
TaskMaster said:
why limit yourself .... sure if you want a smaller image 250W will suffice ..... That link you showed me looks good, but at 80" wide its not as big as it could be. My PJ is at 120inches wide and looks every bit as bright, if not bright
My screen, to calculate square inches ... 86 * 119 = 10234 inches sqaure.
The above posted screen is 80 * 60 (standard 4:3 conversion) = 4800 inches square.
Thats a difference of more than twice the size. Quite substantial in my book.
The inverse square law of light tells us that the intensity of the image is inversly proportional to the square of the distance or in simpler terms: When your projector is 6 feet from the screen it is actually 4 times brighter than it is at 12 feet. I think I remember that right from a photography class.
my image would be roughly around 3 times brighter than it is now if I went to that size a projection., according to the above physics formula.
, I could see opting for a 250W if the cost was MUCH MUCH cheaper ... but it isnt .... its not much more to have a 400W MH bulb, and therefor your PJ will be more versatile ....
Simple put ...... an average LCD will let about %10 of the light pass.... Alot of 400W bulbs will produce 30-33K lumens, about 28k mean lumens .... where as a 250W bulb will produce about 15-16K Mean lumens ..... Thats nearly a difference of more than double the output. And for a projector that can mean alot. I have an amazingly bright image, and I use a 400W w/ reflector ( My results ... http://www.diyaudio.com/forums/showthread.php?s=&threadid=52796)
Will a 250W work yes ..... but you will get a brighter, more managable result with 400W... The light will not saturate through an LCD at that point, also any effecient cooling system will disapate the heat just fine .. (MY PJ runs at 7 degrees over room temp), and the cost of electricity driving it .... will be less than 1 dollar more on the week. (assuming about 10 hours of use per week) ( I can show the electrical forumlas to prove this)
... when you start talking of 600W or 1kW, then you reach a point of light saturation through the LCD.
Scubasteve2365 said:
Because some people do not have the room for that size image and don't plan on their projector moving much once installed. A 15" LCD isn't ideal for a mobile projector. In my shop or living room I simply do not have room for a 120" wide projection, so I see no need to build a unit to do that.
Sure, twice the raw output, but the efficiency of the 400w bulbs is lower meaning % of their output that is directed toward the LCD is lower. The bulbs are larger and not as easily setup for proper reflectors or condensors. These factors, and their supporting fomulae can be found in other threads.
Your hourly estimate is very low for my intended use. Lets say I triple it for arguments sake, that's $150 more a year for electricity alone and the extra heat pumping out in the summer is undesireable too.
I'm sorry but I am sticking to my guns that I don't agree with a blanket statement that you absolutely need a 400watt bulb with a 15" LCD. There are many other factors as well and in many cases less wattage is more than sufficient. Perhaps you are right for a 10' wide image, but I have still seen very impressive results with a image size in that range and a 250watt bulb.
Like I said you DONT ABSOLUTLY NEED IT .... but I had my PJ when first built at about a 90" Diagonal screen, the brightness was CRT LIKE (ALMOST) ....
The point im trying to make, is that you can get more brightness at not much more in cost. Reflectors arent a problem ... I have a perfectly spherical bowl, that came mirror polished at the tune of $8.
Id also like to add, that I believe very few people would get 30Hours out of their PJ a week, thats alot of time to watch TV after the sun goes down... so the electricity bill isnt much of a concern
With a brighter bulb, You could do more low light veiwing .... you can see in my results thread how bright it is with bulbs in the room on ..... imagine if I did go to a smaller screen... how bright the image will be in a lit room
Again ... im not saying it wont work with a 250W ... it obviously will .... But regardless of screen size a 400W will be brighter, and it is money well spent
that why I also pointed out ..... that if there is no point in building a 15" if your screen is going to be small ( you can do that with a 7" and a 250W) ... That way you have some of that mobility ...
The author of this thread was asking suggestions .... 400W will be larger, will dissapate a little more heat (Not an Issue in the summer time either unless you dont have AC). My PJ stays 7-9 degree above room temp ... so in the summer it will run at the same temp as the winter. Will cost a few bucks (if noticeable, mine wasnt) of electricity each month ... but on the upside you can do a large image brigher, your smaller images will be brighter, you wont have to adjust the brightness/contrast settings to throw off your picture quality, and it may be possible to view in a lit room.
It just makes more sense .... commercial PJ's ... something we are trying to rival ... have a higher lumen output bulbs ... higher than that of the 400W bulbs, so why not try to be as close to that as possible ..... This isnt a race to see who can be most effecient, but rather to see how good, bright, evenly lit, quality picture you can produce Even if you slap a 400W in there with no fine tuning, you can come out with a brigher image than someone that did a 250W and fine tuned his to death ....
The point im trying to make, is that you can get more brightness at not much more in cost. Reflectors arent a problem ... I have a perfectly spherical bowl, that came mirror polished at the tune of $8.
Id also like to add, that I believe very few people would get 30Hours out of their PJ a week, thats alot of time to watch TV after the sun goes down... so the electricity bill isnt much of a concern
With a brighter bulb, You could do more low light veiwing .... you can see in my results thread how bright it is with bulbs in the room on ..... imagine if I did go to a smaller screen... how bright the image will be in a lit room
Again ... im not saying it wont work with a 250W ... it obviously will .... But regardless of screen size a 400W will be brighter, and it is money well spent
that why I also pointed out ..... that if there is no point in building a 15" if your screen is going to be small ( you can do that with a 7" and a 250W) ... That way you have some of that mobility ...
The author of this thread was asking suggestions .... 400W will be larger, will dissapate a little more heat (Not an Issue in the summer time either unless you dont have AC). My PJ stays 7-9 degree above room temp ... so in the summer it will run at the same temp as the winter. Will cost a few bucks (if noticeable, mine wasnt) of electricity each month ... but on the upside you can do a large image brigher, your smaller images will be brighter, you wont have to adjust the brightness/contrast settings to throw off your picture quality, and it may be possible to view in a lit room.
It just makes more sense .... commercial PJ's ... something we are trying to rival ... have a higher lumen output bulbs ... higher than that of the 400W bulbs, so why not try to be as close to that as possible ..... This isnt a race to see who can be most effecient, but rather to see how good, bright, evenly lit, quality picture you can produce Even if you slap a 400W in there with no fine tuning, you can come out with a brigher image than someone that did a 250W and fine tuned his to death ....
TaskMaster said:
exactly ... I dont have mobility either .... all the more reason to NOT build a 15, and do a 7" lilliput. What point does this have in using a 250W rig over a 400W? When I spoke of versitility I mean variance in case you move, or re-arrange your funiture .... not enogh variance to throw the PJ into your car and to take it to work with you everyday ...
TaskMaster said:
Who told you that .... Yeah a 400W may be less effiecent in Lumens per dollar .... but they use the same technology arc envelope that lower wattage bulbs use .... Just because the bulb is brighter does not mean that the light flies around more uncontrollably .... besides when used with a reflector the light becomes controlled equally well. But regardless of these factors ... assuming they ARE true ... more light will still hit the LCD, and you will STILL have a brighter image, yeilding a more theater like experience ..... Which is our GOAL ....
TaskMaster said:
The summer wont matter, unless you are going to have your PJ outside during the day time underneath the blistering sun ..... MY PJ stays 7-9 degrees above room temp, so in the summer when my room temp is 70 degrees .... my PJ will be 80 degrees or less. As for Heat that the bulb itsel generates it is not that noticeable. While it may be more dratmatic inside the enclosure (which wont matter if you have a proper cooling system), the temperature will cool very fast once it comes out of the fan and hits ambient room temperature. Id be willing to bet that you couldnt even tell the difference two feed away from the box between the heat of a 250W and a 400W. This is a very small difference ... especially when considering with a 1kW MH bulbs and such out there.
Im not suggesting that you dont stick with your guns ... Nor did I say it was absolutly neccessary and vital to a DIY PJ to function. I just merely pointed out that you image will be brighter, regardless of screen size. And for us DIY guys .. output brightness is a big concern.
jfguay2 said:
I have a 400W and I use a reflector .... this gives me even more brightness .... see my results thread to compare my results ....
It seems we will have to agree to disagree.
The point I'm making is it's not always needed so if not, avoid the aditional costs.
Even at your low estimate it's more than $50 a year. That's $50 more than I like to throw away.
And I'm just saying the money well spent part is a subjective opinion.
Well, I am using a 15" since I have one that supports 420p, 720p, 1080i, component, composite, s-video and VGA. I haven't seen a 7" that will do that and I think it will be quite nice with a 6-7 foot screen. I believe the 7" supports 420p at best. I don't know why screen size means I should sacrifice resolution. I don't think there is a WUXGA project going on because people want a 20 foot screen... well, most people. 🙂
It's all fun for me.
A geometry teacher. The larger wattage bulbs have larger outter bulb dimensions regardless of the arc tube size. Again, well discussed in other threads and a point I don't care to debate.
Well it puts more heat in the room which either makes the room hotter or costs you more for the AC. How much more? I don't know - pennies for sure. Oh well, with three kids, I save all my pennies.
Well, you said:
which I wanted to point out was an opinion with which some folks don't agree and there have been some nice 15" 250w projectors.
Scubasteve2365 said:
The point I'm making is it's not always needed so if not, avoid the aditional costs.
Even at your low estimate it's more than $50 a year. That's $50 more than I like to throw away.
And I'm just saying the money well spent part is a subjective opinion.
Well, I am using a 15" since I have one that supports 420p, 720p, 1080i, component, composite, s-video and VGA. I haven't seen a 7" that will do that and I think it will be quite nice with a 6-7 foot screen. I believe the 7" supports 420p at best. I don't know why screen size means I should sacrifice resolution. I don't think there is a WUXGA project going on because people want a 20 foot screen... well, most people. 🙂
It's all fun for me.
A geometry teacher. The larger wattage bulbs have larger outter bulb dimensions regardless of the arc tube size. Again, well discussed in other threads and a point I don't care to debate.
Well it puts more heat in the room which either makes the room hotter or costs you more for the AC. How much more? I don't know - pennies for sure. Oh well, with three kids, I save all my pennies.
Well, you said:
which I wanted to point out was an opinion with which some folks don't agree and there have been some nice 15" 250w projectors.
Wow, I must be really slow then for trying to peice together a projector with an 11k lumen 500 watt halogen then eh?
Wait, it only costs $6.95 CAD for a cheap experiment, if I like the results with that lowish output bulb I won't upgrade, if it looks terrible then I will go for a 250 watt arc type bulb.
I as well am going with the benq mentioned above, (odered and in the mail) and got it because it was cheaper than the 7inchers I could get and has a higher native resolution.
I don't plan on projecting for a football stadium nor do most people and as always everyone's goals are different so I don't see what the big deal is with someone trying to save some long term cash. (Which I know I won't be as the halogen sucks back the juice, but I can get it anywhere for very little outlay and no duty etc).
Go for it TaskMaster.
Wait, it only costs $6.95 CAD for a cheap experiment, if I like the results with that lowish output bulb I won't upgrade, if it looks terrible then I will go for a 250 watt arc type bulb.
I as well am going with the benq mentioned above, (odered and in the mail) and got it because it was cheaper than the 7inchers I could get and has a higher native resolution.
I don't plan on projecting for a football stadium nor do most people and as always everyone's goals are different so I don't see what the big deal is with someone trying to save some long term cash. (Which I know I won't be as the halogen sucks back the juice, but I can get it anywhere for very little outlay and no duty etc).
Go for it TaskMaster.
FIGHT FIGHT FIGHT! 😛
interesting debate guys... I'm actually about to buy a mh setup and this is something I've been weighing up. My decision so far has been 400 (with reflector and condensor... similar to philip0101s' setup), mostly because I can't have my mate with a commercial projector laughing at mine!
My current screen is only 60" too lol (in my bedroom), should make for a decent image I hope!
interesting debate guys... I'm actually about to buy a mh setup and this is something I've been weighing up. My decision so far has been 400 (with reflector and condensor... similar to philip0101s' setup), mostly because I can't have my mate with a commercial projector laughing at mine!
My current screen is only 60" too lol (in my bedroom), should make for a decent image I hope!
Bigg'un said:
I'm trying mine with a 150W CDMT that does about 13,000 lumens and I may well need to upgrade, but it's the challenge!
When I was talking about setting up a reflector and the 400watt bulb being larger I was thinking of a mogul base 400 vs an HQI 250
. Obviously an HQI 250 versus an HQI 400 are virtually the same size (1/8" dia difference I think) and ScubaSteve is right that both can be setup equally well with a reflector and condensor. 😉
Well ..... I guess we will have to agree to disagree for now .....
I made a PJ with 250W first, and I wanted more brightness ... this is maybe because I worked for a custom home theater shop and I was used to the brightness of commercial projectors ..... So Maybe ... my eye is just trained to expect a certain level of brightness, and nothing less would be acceptable.
Even at my 400W now, I wish I had more brightness ..... and I would never be truely truely satisfied untill I reached the brightness output higher end commercial projectors.
the relevency of my RECOMENDATION, was that I have personally compared my PJ to the lower level infocus and others PJs, Similar to how Hertzman did in his projector from phillipines thread, however I found my PJ to be similarily bright to the infocus, but with better color tone, also like Hertzman found.
With that said I compared it to a $7000 sharp Widescreen DLP projector, and I was astounded at how pathetic my PJ looked compared to this ..... therefor I guess its all up to what the individual expects their PJ to look like.
If you followed Hertzman plog, you will notice that he consistently tried to increase the output brightness of his PJ, Especially after he compared to the commercial one. And thats at his 70x70 screen size.
Task, I hope your not sore with me, or discredit my knowledge because I argued this point probably further than I should (Not this first time in my life Ive done that, and thats why Im considering Law school after my B.S. in engineering), After you build your PJ, try to look at it and a CRT at the same time, and you will start to appreciate the desire for more brightness at that point. Even if you only have a small screen.
Biggun, In addition to the low lumen output of that halogen, it will have a really bad color temp. Halogens arent exactly a white light by any means .... you will want a bulb that has a color temp of 4000k to 5200K .... with the 5200K being the better end of the spectrum.
With that said, Ill plug lumen lab again ..... they have a really nice Ushio bulb that is 5200K. Its a quality color bulb, the best Ive sourced, unfortunatly at the sacrifice of lumen output ..... Its about 8000 lumens less than the Ushio Pulse strike Lamp. I personally dont have it ... but alot of people have reported that the color temp difference is amazing ....
I made a PJ with 250W first, and I wanted more brightness ... this is maybe because I worked for a custom home theater shop and I was used to the brightness of commercial projectors ..... So Maybe ... my eye is just trained to expect a certain level of brightness, and nothing less would be acceptable.
Even at my 400W now, I wish I had more brightness ..... and I would never be truely truely satisfied untill I reached the brightness output higher end commercial projectors.
the relevency of my RECOMENDATION, was that I have personally compared my PJ to the lower level infocus and others PJs, Similar to how Hertzman did in his projector from phillipines thread, however I found my PJ to be similarily bright to the infocus, but with better color tone, also like Hertzman found.
With that said I compared it to a $7000 sharp Widescreen DLP projector, and I was astounded at how pathetic my PJ looked compared to this ..... therefor I guess its all up to what the individual expects their PJ to look like.
If you followed Hertzman plog, you will notice that he consistently tried to increase the output brightness of his PJ, Especially after he compared to the commercial one. And thats at his 70x70 screen size.
Task, I hope your not sore with me, or discredit my knowledge because I argued this point probably further than I should (Not this first time in my life Ive done that, and thats why Im considering Law school after my B.S. in engineering), After you build your PJ, try to look at it and a CRT at the same time, and you will start to appreciate the desire for more brightness at that point. Even if you only have a small screen.
Biggun, In addition to the low lumen output of that halogen, it will have a really bad color temp. Halogens arent exactly a white light by any means .... you will want a bulb that has a color temp of 4000k to 5200K .... with the 5200K being the better end of the spectrum.
With that said, Ill plug lumen lab again ..... they have a really nice Ushio bulb that is 5200K. Its a quality color bulb, the best Ive sourced, unfortunatly at the sacrifice of lumen output ..... Its about 8000 lumens less than the Ushio Pulse strike Lamp. I personally dont have it ... but alot of people have reported that the color temp difference is amazing ....
The reason I got my particular halogen was because it said "Brilliant White Light" (sylvania 500T3Q/CL/BL/119mm) and compared to a normal halogen it is whiter, but not really white white, I agree. But again, this is an experiment and I thought that at ~3200k colour should be ok for my cheapo purposes. I can't find the bulb on the sylvania site anymore...so I can't give exact colour etc, but I know it is rated at 11k lumens for sure and had a colour index rating of 100 (makes sense as the rating uses incandacent bulbs as the baseline afaik).
It *should be bright enough for my purposes as only my wife is at home during the day and there really ins't anytime to be watching a home theatre set up while the sun is up with the baby and all 🙂 So when I get home it should be dim enough with the really heavy drapes we just made to view the projection. I plan on going the vinyl shade route so I can place it at the optimum distance from the projector for light intensity/size. I think anything will be a step up from my 21 year old 19" tv 🙂 lol So even if I can "only" get a nice picture at 60-80 inches diagonal, I am not going to whine for the money invested is minimal compared to what a nice lcd rear projection tv of even 42" would cost. I have been holding out for something that is capable of reproducing the widescreen experience for less than $1000 and this seems to be the best way for us to do it in our household.
cheers (I'll let you all know if I ever get my monitor from the post office...I really think someone in Quebec [last known location] has a benQ monitor on their desk atm). ARRRRGGG
It *should be bright enough for my purposes as only my wife is at home during the day and there really ins't anytime to be watching a home theatre set up while the sun is up with the baby and all 🙂 So when I get home it should be dim enough with the really heavy drapes we just made to view the projection. I plan on going the vinyl shade route so I can place it at the optimum distance from the projector for light intensity/size. I think anything will be a step up from my 21 year old 19" tv 🙂 lol So even if I can "only" get a nice picture at 60-80 inches diagonal, I am not going to whine for the money invested is minimal compared to what a nice lcd rear projection tv of even 42" would cost. I have been holding out for something that is capable of reproducing the widescreen experience for less than $1000 and this seems to be the best way for us to do it in our household.
cheers (I'll let you all know if I ever get my monitor from the post office...I really think someone in Quebec [last known location] has a benQ monitor on their desk atm). ARRRRGGG
Well thanks for the discussion, it sure was interesting.
I might just go with a 400 watts metal halide and give it a try.
Yesterday, I went to my local hardware store and bought a philips ed37 400 watts.
Would it work alright? I think it's a 4000K 65 Cri bulb so I am hoping it would do the trick.
Along with it I bought a Philips Core and coil ballast, and I tried it in my overhead projector, but the image was only bright in the middle. I am thinking that this might have something to do with the fact the because of the size of the bulb, it's no longer at the focal point of the fresnel. Any idea?
I might just go with a 400 watts metal halide and give it a try.
Yesterday, I went to my local hardware store and bought a philips ed37 400 watts.
Would it work alright? I think it's a 4000K 65 Cri bulb so I am hoping it would do the trick.
Along with it I bought a Philips Core and coil ballast, and I tried it in my overhead projector, but the image was only bright in the middle. I am thinking that this might have something to do with the fact the because of the size of the bulb, it's no longer at the focal point of the fresnel. Any idea?
that bulb is huge ....if I remember correctly ...... You might want to buy a 400W MH bulb online thats in a ED28 package ... venture makes a decent on called the Eye bulb .... just make sure it runs of an M59 ballast which is the one you already have ...
with that big a bulb you will not find a reflector for it ....
I think its only safe to assume that not be at the focal point off the fresnel is why its only bright in the middle ....
but if your getting a big circle on the wall, then the fresnel may be reversed ....
with that big a bulb you will not find a reflector for it ....
I think its only safe to assume that not be at the focal point off the fresnel is why its only bright in the middle ....
but if your getting a big circle on the wall, then the fresnel may be reversed ....
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