All that matters is that you have a focusable light source. 10% spread may sound little but i doubt it will be good enough.
About a 400W MH. The 400W mogul base bulbs are huge, but they only have a 'very small' light source within. As long as you use a bulb with a clear outer shell (and a humongous condensor+reflector) its still way better than any multiple light source that i have seen.
Good luck though, as you ordered your bulbs you will be the first here to have any hands on experience with this kind of lighting.
Let us know how it turns out.
About a 400W MH. The 400W mogul base bulbs are huge, but they only have a 'very small' light source within. As long as you use a bulb with a clear outer shell (and a humongous condensor+reflector) its still way better than any multiple light source that i have seen.
Good luck though, as you ordered your bulbs you will be the first here to have any hands on experience with this kind of lighting.
Let us know how it turns out.
If you're wondering why I'm being such a freak about this, follow these links:
http://www1.ushio.co.jp/catalog/100e/1035.html
http://www.highend.com/news/colortemp.html
http://www.venturelighting.com/TechCenter/Lamps/color_of_light.htm
I have done woodworking under 400MH bulbs, and I can tell you their color sucks compared to sunlight. Even the short arc projector bulbs are only CRI 85. And when you use a standard MH400, like you are talking about, color is bad, bad, bad.... I will never try to match wood stains under MH, I will go standard bulb or halogen any day. I know those are yellower options, but at least they are consistant. My results the next day in the sunlight are much more accurate vs. MH. So if I have this problem matching stain color under MH -- what makes anyone think it will be better for a projector?
If you really think I am going to have this much problem, should I point several of these lights at a convex-convex lense so that the "point source" is inside the lense, and then let that diverge out to a fresnel?
http://www1.ushio.co.jp/catalog/100e/1035.html
http://www.highend.com/news/colortemp.html
http://www.venturelighting.com/TechCenter/Lamps/color_of_light.htm
I have done woodworking under 400MH bulbs, and I can tell you their color sucks compared to sunlight. Even the short arc projector bulbs are only CRI 85. And when you use a standard MH400, like you are talking about, color is bad, bad, bad.... I will never try to match wood stains under MH, I will go standard bulb or halogen any day. I know those are yellower options, but at least they are consistant. My results the next day in the sunlight are much more accurate vs. MH. So if I have this problem matching stain color under MH -- what makes anyone think it will be better for a projector?
If you really think I am going to have this much problem, should I point several of these lights at a convex-convex lense so that the "point source" is inside the lense, and then let that diverge out to a fresnel?
Current MH bulbs have a cri of over 90. I haven't seen any bulb made by any respectable (==large/international, you know, the guys that spend millions $$$/year on r&d) claim a cri of over 96 for any kind of bulb.
What I would have done in your case is buy 2 bulbs and try them 1st to see if condensor lenses are needed. Or maybe look at light guides / prisms to collect light from multiple bulbs.
What I would have done in your case is buy 2 bulbs and try them 1st to see if condensor lenses are needed. Or maybe look at light guides / prisms to collect light from multiple bulbs.
90?
Not the bulbs I buy, what's the cri of the 250 double ended at diylabs.org?
http://www.sylvania.com/business/news/0402.htm
Not the bulbs I buy, what's the cri of the 250 double ended at diylabs.org?
http://www.sylvania.com/business/news/0402.htm
Current==current design, not left over stock 🙂
Look at this (what i'm using, just the single ended that is)
http://www.lighting.philips.com/nam/feature/mcolor/data_sheets/cdm009.php
Look at this (what i'm using, just the single ended that is)
http://www.lighting.philips.com/nam/feature/mcolor/data_sheets/cdm009.php
Wow, that's the most even spectrum from a MH I've ever seen, but even with a cri of 96, you see that big yellow spike? that's the bane of all MH's and why I can never mix stain under one (stains have a large number of yellows in them) When you look at the general Home Depot mogul base MH's that people on this forum are using, their color spectrum sucks.
Are you going to have to use some heat mirror in front of these bulbs?
"Use only in fully enclosed fixtures capable of withstanding particles of glass having temperatures up to 1000 ºC. Lens/diffuser material must be heat resistant. Consult fixture manufacturer regarding the suitability of the fixture for this lamp"
Post pics when you're done, I'll do the same.
Just FYI, my goal is to beat the brightness of my nec1050 and to match or beat it's color rendering....
Are you going to have to use some heat mirror in front of these bulbs?
"Use only in fully enclosed fixtures capable of withstanding particles of glass having temperatures up to 1000 ºC. Lens/diffuser material must be heat resistant. Consult fixture manufacturer regarding the suitability of the fixture for this lamp"
Post pics when you're done, I'll do the same.
Just FYI, my goal is to beat the brightness of my nec1050 and to match or beat it's color rendering....
I'm using it between the std. (glass) condensor lens+reflector mirror. Both are mounted in a steel frame with the bulb in between. Even if the bulb explodes I dont think any harm will come from it. (And I'm planning to change the bulb at around 5000hrs as I only payed 8 euro/piece)
Well...put your fresnel before the lcd i think
Well i think Jbell has a good idea and i can't wait to hear about how it pans out....One thing though is that from what i hear in this forum, you should put the fresnel before the LCD so that it doesn't degrade the image quality...From what i understand, OHP's use the double fresnel before the lcd panel...The Fresnel facing the light source turns the light rays to parallel rays while the Fresnel facing the lcd turns the parallel rays into converging rays which pass through the panel and converge around the pj lens...that's right, right? But since Fresnels are etched "REAL LENS" simulators..they may degrade the image quality if you put it AFTER the lcd...right?
AS for the narrow beam spread out of the solux that RAPSAC is discounting...HOW ABOUT this idea:
I noticed on alot of the FRESNEL supply sites (the actual commercial ones) They often show pictures of "Postcard" Fresnel sheets--Sheets of small Fresnels arranged in arrays....e.g. a 5x4 sheet of 4" fresnel squares....
SO...Why not shine your array of SOlux's at one of these sheets...one little fresnel for each bulb....That way you REALLY make those rays VERY PARALLEL.....Then you could use the 12x12 Fresnel (before the LCD??) to converge these parallel rays to the pj lens....Sound good?
Property
Well i think Jbell has a good idea and i can't wait to hear about how it pans out....One thing though is that from what i hear in this forum, you should put the fresnel before the LCD so that it doesn't degrade the image quality...From what i understand, OHP's use the double fresnel before the lcd panel...The Fresnel facing the light source turns the light rays to parallel rays while the Fresnel facing the lcd turns the parallel rays into converging rays which pass through the panel and converge around the pj lens...that's right, right? But since Fresnels are etched "REAL LENS" simulators..they may degrade the image quality if you put it AFTER the lcd...right?
AS for the narrow beam spread out of the solux that RAPSAC is discounting...HOW ABOUT this idea:
I noticed on alot of the FRESNEL supply sites (the actual commercial ones) They often show pictures of "Postcard" Fresnel sheets--Sheets of small Fresnels arranged in arrays....e.g. a 5x4 sheet of 4" fresnel squares....
SO...Why not shine your array of SOlux's at one of these sheets...one little fresnel for each bulb....That way you REALLY make those rays VERY PARALLEL.....Then you could use the 12x12 Fresnel (before the LCD??) to converge these parallel rays to the pj lens....Sound good?
Property
good idea on the multi-fresnel, I'll keep it in mind if I can't get an even light source.
Waiting on things to show up......
I'll let you know on fresnel before or after on effects. (My assumption is that screen door effect is magnified if converging light is passed through the lcd, and that it is minimized if parallel light is passing through it. Just a theory, I'll post my results -- good or bad.
Waiting on things to show up......
I'll let you know on fresnel before or after on effects. (My assumption is that screen door effect is magnified if converging light is passed through the lcd, and that it is minimized if parallel light is passing through it. Just a theory, I'll post my results -- good or bad.
Re: Well...put your fresnel before the lcd i think
Correct me if I am mistaken, but all fresnels have a single focal point. If he has an array of fresnels and lights that should suffice. If you add a second fresnel before the LCD, it would reduce lights because the facits of the fresnel will be tuned to a different point.
I also have a question for the thread. Are my calculations wrong, or are they advertising these as producing 30K lumens in the middle of their power range?
Regards,
BT
Property said:
Correct me if I am mistaken, but all fresnels have a single focal point. If he has an array of fresnels and lights that should suffice. If you add a second fresnel before the LCD, it would reduce lights because the facits of the fresnel will be tuned to a different point.
I also have a question for the thread. Are my calculations wrong, or are they advertising these as producing 30K lumens in the middle of their power range?
Regards,
BT
Nope, 30,000 lux, that's close to 3,000 lumens @ 2' over a 4" diameter for a 10degree 3500K bulb.
http://www.soluxtli.com/3500k.htm
If you follow the math, I should be able to put up about 350 lumens at a 72" diagonal pic -- That's bright. Remember that typical office lighting is 50 lumens, and concentrated work light is 100 lumens.
http://www.technika.com/navpage/light.htm
this give lux to fc to lumen conversions.
http://www.soluxtli.com/3500k.htm
If you follow the math, I should be able to put up about 350 lumens at a 72" diagonal pic -- That's bright. Remember that typical office lighting is 50 lumens, and concentrated work light is 100 lumens.
http://www.technika.com/navpage/light.htm
this give lux to fc to lumen conversions.
Re: Re: Well...put your fresnel before the lcd i think
What happens is that most people on here and all the OHP people use double fresnels...One to turn the point source light rays (located at it's focus) to parallel beams and the the next one to refocus those parallel beams toward the projection lens.... Now whether you place the second fresnel before or after your LCD panel (Before = the refocusing light rays pass through the LCD; AFTER = the parallel light rays pass through the LCD and THEN are focused by the second fresnel) Seems to be immaterial....must OHP's it seems do the BEFORE way..while there has been good success doing it the AFTER way and theory seems to say AFTER is actually better for a few reasons... one of which i think Jbell hinted at a few posts back
bigtinker said:
What happens is that most people on here and all the OHP people use double fresnels...One to turn the point source light rays (located at it's focus) to parallel beams and the the next one to refocus those parallel beams toward the projection lens.... Now whether you place the second fresnel before or after your LCD panel (Before = the refocusing light rays pass through the LCD; AFTER = the parallel light rays pass through the LCD and THEN are focused by the second fresnel) Seems to be immaterial....must OHP's it seems do the BEFORE way..while there has been good success doing it the AFTER way and theory seems to say AFTER is actually better for a few reasons... one of which i think Jbell hinted at a few posts back
CRI me a river
5{ ur solux CRI of 99.459873
is confusing me....because you also say it's color blah blah is 3500k...Now from what i'm reading, everybody is saying we need light around 6000k and that 3500k is really the very bottom of color blah blah that we need....
So what is the difference/similarities/trade-offs/advantages/etc...
of having a CRI so high but a color blah blah so low?
5{ ur solux CRI of 99.459873
is confusing me....because you also say it's color blah blah is 3500k...Now from what i'm reading, everybody is saying we need light around 6000k and that 3500k is really the very bottom of color blah blah that we need....
So what is the difference/similarities/trade-offs/advantages/etc...
of having a CRI so high but a color blah blah so low?
you can get 20,000K reef bulbs if you want -- depends on what you want. If you want the most natural looking light possible, you go with what the sun provides. That is a very smooth spectral scale with no spikes in specific color bands.
The reason there is a CRI scale, is to state how close to the sun's color a particular light source is.
There is also a lot of human optical research that has indicated that "white" light is a different color in dim light vs. bright light as the rods and cones in the retina are stimilated differently in bright vs. dim environments. That being said, 3500K is the "best" visual light in dim environments, and that is what is used in museum's. In bright light, 4700K is "white." (If you want to prove that to yourself, look at your car's headlights at night -- they look white, and during the day -- they look yellow)
The problem comes when you start having a light source with "spikes" in it's spectral curve, to approach "white" a higher kelvin corrected color is necessary to "approximate" white when other colors are missing. So when you are using MH or other arc based bulbs with very high spikes in specific color bands, the Kelvin rating of the bulbs is fairly meaningless, the cri is much more important. Just think of the color change of something under incandecents vs fluorescent's. Fluorescents have many of the same color flaws as MH bulbs, as there are typically 3 or 4 very narrow color bands that are 300% or more brighter than other colors.
If you want an audio analogy, think of the cars that have all bass. You can hear them booming from blocks away -- but is that the best representation of the original music? It's obviously impressive, but not accurate. The same goes for light sources.
So... My thoughts are: Whenever you look for a light source, check it's cri -- that's much more important than kelvin.
The reason there is a CRI scale, is to state how close to the sun's color a particular light source is.
There is also a lot of human optical research that has indicated that "white" light is a different color in dim light vs. bright light as the rods and cones in the retina are stimilated differently in bright vs. dim environments. That being said, 3500K is the "best" visual light in dim environments, and that is what is used in museum's. In bright light, 4700K is "white." (If you want to prove that to yourself, look at your car's headlights at night -- they look white, and during the day -- they look yellow)
The problem comes when you start having a light source with "spikes" in it's spectral curve, to approach "white" a higher kelvin corrected color is necessary to "approximate" white when other colors are missing. So when you are using MH or other arc based bulbs with very high spikes in specific color bands, the Kelvin rating of the bulbs is fairly meaningless, the cri is much more important. Just think of the color change of something under incandecents vs fluorescent's. Fluorescents have many of the same color flaws as MH bulbs, as there are typically 3 or 4 very narrow color bands that are 300% or more brighter than other colors.
If you want an audio analogy, think of the cars that have all bass. You can hear them booming from blocks away -- but is that the best representation of the original music? It's obviously impressive, but not accurate. The same goes for light sources.
So... My thoughts are: Whenever you look for a light source, check it's cri -- that's much more important than kelvin.
Probably a crap. but $2.06 a sheet + $4 shipping is not that bad to try it.
http://www.3dlens.com/media/fresnel_408(large).jpg
http://www.3dlens.com/media/fresnel_408(large).jpg
Check em
Check these out...looks like they are meant to replace your solux-type par16s.
Wonder what kind of "beam" they put out...looks like fluroescent tube in them
http://www.rapidelectronics.co.uk/elecprod_23-4756.htm
jbell: "I hate waiting."
Me too
Check these out...looks like they are meant to replace your solux-type par16s.
Wonder what kind of "beam" they put out...looks like fluroescent tube in them
http://www.rapidelectronics.co.uk/elecprod_23-4756.htm
jbell: "I hate waiting."
Me too
cooler than a fluoerscent
How about this to keep those halogen's cool:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2320049021&category=20507
How about this to keep those halogen's cool:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2320049021&category=20507
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