Question for People Who Use Bias Lighting.

[ManBearPig]

Where did you get yours? Any tips on which to buy?

I've seen this recommended a couple of times, but I wish I could find something cheaper:

cinema quest inc

I have a Samsung LN52B750 if it matters. Just looking to improve my night time blacks! I have very very minor flashlighting on the bottom two corners, and i was hoping this would help in that regard as well as making blacks appear a bit blacker. If not i really dont mind, but it would be nice. This is what they are for, no?

thanks everyone, happy holidays!

 

[CubanlB]

After reading the description I am left wondering if it matters what color my wall is painted.

Anyway, I don't think your room lighting is going to help with any type of unevenness in the back lighting of your TV. I think you could just buy different light bulbs to achieve the same effect as this would provide.

However, I could be totally wrong.

 

[ManBearPig]

After reading the description I am left wondering if it matters what color my wall is painted.

Anyway, I don't think your room lighting is going to help with any type of unevenness in the back lighting of your TV. I think you could just buy different light bulbs to achieve the same effect as this would provide.

However, I could be totally wrong.

I dunno, i figured i would ask. It seems like a lot of people do this. Also, i opened the window behind my tv once, and blacks were BLACK. trying to achieve the same effect for night time. Walls are off white.

Thanks for your input!

 

[Modelworks]

I work with studios where they have monitors set up for final compositing to adjust color and effects. Bias lighting has nothing to do with the tv. It is used because of how the cells of the eye can become overly sensitive to light in a dark room. In a dark room the eye sees a gamut of light that is skewed towards the very low end. Pilots and ships use red light for this same reason, red light btw is the only light that the eye will not become saturate with over time, and why that color is used. Totally dark rooms would be fine if you were watching a movie that is totally dark throughout the movie. The problem is most film content exist in the middle range, so in a dark room you eyes are trying to adjust to the darkness while the LCD light is hitting your eyes like a beacon .

A bias light is used to bring the light your eyes receive up to average level of the film you are watching usually 6500K color temp. It keeps your eyes from having to constantly adjust to varying light levels and makes watching films much more enjoyable.

The bulbs corona should not be visible by the viewer and it should not be brighter than the brightest scene in the film. I like the 30 watt , 6500k bulbs. Socket and bulb is about $10 . Position it behind the tv so it cannot be seen from the front except for the light it cast on the wall and around the frame. The big thing is make sure it says 6500k. The ones that say daylight or full spectrum sometimes are the right color but sometimes not so best stick to ones that state 6500k color.

 

[ManBearPig]

I work with studios where they have monitors set up for final compositing to adjust color and effects. Bias lighting has nothing to do with the tv. It is used because of how the cells of the eye can become overly sensitive to light in a dark room. In a dark room the eye sees a gamut of light that is skewed towards the very low end. Pilots and ships use red light for this same reason, red light btw is the only light that the eye will not become saturate with over time, and why that color is used. Totally dark rooms would be fine if you were watching a movie that is totally dark throughout the movie. The problem is most film content exist in the middle range, so in a dark room you eyes are trying to adjust to the darkness while the LCD light is hitting your eyes like a beacon .

A bias light is used to bring the light your eyes receive up to average level of the film you are watching usually 6500K color temp. It keeps your eyes from having to constantly adjust to varying light levels and makes watching films much more enjoyable.

The bulbs corona should not be visible by the viewer and it should not be brighter than the brightest scene in the film. I like the 30 watt , 6500k bulbs. Socket and bulb is about $10 . Position it behind the tv so it cannot be seen from the front except for the light it cast on the wall and around the frame. The big thing is make sure it says 6500k. The ones that say daylight or full spectrum sometimes are the right color but sometimes not so best stick to ones that state 6500k color.

Awesome! I know it has nothing to do with the tv itself, i think my posts just didnt make sense, which is typical haha. Thanks so much for the reliable information. Do you have any places in mind where I could buy one? Im glad its only $10! Win and win...you rock my friend.

 

[CubanlB]

Good information. That was more along the lines that I was guessing but I had nothing to back it up with.

 

[Modelworks]

Awesome! I know it has nothing to do with the tv itself, i think my posts just didnt make sense, which is typical haha. Thanks so much for the reliable information. Do you have any places in mind where I could buy one? Im glad its only $10! Win and win...you rock my friend.

You can use any light source you like that fits your situation for how best to place the light behind the tv. The biggest thing is to make sure the light color is 6500K. You can use florescent , incandescent, LED, or anything else , that part is up to you.
They sell some CFL lights that are 6500K with normal bulb threads for about $5 . Then all you would need is a cord with a socket, you can get those for about $5 . Hang it over the back of the tv and you got the correct setup.

I am currently looking at using a more costly but interesting approach. A block of LED lights. I have seen them on ebay for about $25 and they plug directly into the all. They also run cooler compared to CFL lights. The problem is going to be getting LED output that is at the 6500K level. Really hard to do without some meter to calibrate it to.

 

[s44]

I've set up a ghetto version with the 6500k bulb -- fairly low-power, though, more like 15W CFL than 30 -- and a super-cheap lamp pointed at the wall behind the TV. It's worked surprisingly well for years.

 

[iRONic]

Where did you get yours? Any tips on which to buy?

I've seen this recommended a couple of times, but I wish I could find something cheaper:

cinema quest inc

thanks everyone, happy holidays!

Here's the invoice from the one I bought 12/05. On the second bulb but I still luv it. 50" DLP.

------------------------------------------------------
Order Number 4XXXXX Items Ordered:
------------------------------------------------------

Item Number: IL-01
Item Name: Ideal-Lume Standard
Options: None.
Quantity: 1
Price: 44.95

 

[BoberFett]

Thanks for the informative post Modelworks.

 

[0roo0roo]

i simply use an ikea grono lamp and a low power cfl from ikea as well. reduces eye strain. blacks..not care so much

 

[Rubycon]

The problem is going to be getting LED output that is at the 6500K level. Really hard to do without some meter to calibrate it to.

RGB arrays can adjust from any color temp you like just by independent control of each channel bank.

 

[ManBearPig]

Here's the invoice from the one I bought 12/05. On the second bulb but I still luv it. 50" DLP.

------------------------------------------------------
Order Number 4XXXXX Items Ordered:
------------------------------------------------------

Item Number: IL-01
Item Name: Ideal-Lume Standard
Options: None.
Quantity: 1
Price: 44.95

Sweet, how did you get ~$15 off!? Are the bulbs expensive (hopefully you didnt have to pay $45 for just the bulb!

 

[ManBearPig]

Also...can i get these at any store, like walmart or something, or are they only sold in more specialized stores?

 

[iRONic]

Sweet, how did you get ~$15 off!? Are the bulbs expensive (hopefully you didnt have to pay $45 for just the bulb!

No discount, I bought it in 2005. IIRC the replacement bulbs are ~$20.

 

[kalrith]

I went to Lowe's and spent $10 on a flourescent light fixture and a 6500K bulb. I'm not sure about incandescent, but I've read in the past that LEDs do not put off as accurate of a color as flourescents. So, even if LEDs state that they're 6500K, they might not be. The CRI number is also important on flourescents. If a bulb says it's 6500K but has a 70 CRI, then that's so low that you're probably not getting 6500K. Shoot for a CRI of 90 or above. If you want to read more, check out this 1800-post avsforum thread.

 

[ManBearPig]

thanks for the info kal.

ill try to go check it out tomorrow. do i need to get multiple of these? ive seen some people have as many as 4, heh.

 

[Modelworks]

RGB arrays can adjust from any color temp you like just by independent control of each channel bank.

Yeah, the problem is I don't own a color meter so getting it to the correct value I have to 'eye' it. I thought of implementing something like ambi light from philips with some sensors on the front of the tv that could vary the color vs what is on screen, just not sure all the work would be worth it.

 

[Rubycon]

Yeah, the problem is I don't own a color meter so getting it to the correct value I have to 'eye' it. I thought of implementing something like ambi light from philips with some sensors on the front of the tv that could vary the color vs what is on screen, just not sure all the work would be worth it.

Yes TNE for this can be frustrating because what looks great today may look twisted tomorrow. After a while it drives you crazy!

 

[arrfep]

Came across this a few days ago, maybe it'll help:

http://www.instructables.com/id/Give-your-HDTV-the-Philips-Ambilight-effect-on-the/

 

[kalrith]

thanks for the info kal.

ill try to go check it out tomorrow. do i need to get multiple of these? ive seen some people have as many as 4, heh.

It depends on how close your set is to the wall. Mine is about a foot away, so one ~15" flourescent in the middle back of the screen does the trick. If yours is wall-mounted or super close to the wall, then you might need two. You'll want them going vertical with one on the left and one on the right as seen in the following picture:

The flourescent(s) will probably put off too much light by default, so you'll want to cover some of it with aluminum foil until it's the right amount of light. To determine the amount of light to use, put up an all-white picture on your screen and have the brightness on the wall match that as closely as possible. For me this was achieved by covering about the middle 7" of the light, leaving about 4" of the bulb exposed at each end. If this isn't making sense, I can post a pic of my light tomorrow.

 

[ManBearPig]

That makes perfect sense. Would the bulb give off any heat? My TV isnt mounted and its pretty far from the wall. i could probably move it up a bit if need be too.

Did you just velcro it to the TV? ive seen people do that in that thread you posted from AVS. the rope light seemed the easiest to use but i couldnt figure out if it was accurate or not amongst their squabbling.

 

[kalrith]

That makes perfect sense. Would the bulb give off any heat? My TV isnt mounted and its pretty far from the wall. i could probably move it up a bit if need be too.

Did you just velcro it to the TV? ive seen people do that in that thread you posted from AVS. the rope light seemed the easiest to use but i couldnt figure out if it was accurate or not amongst their squabbling.

Being a flourescent, the light gives off hardly any heat. I actually used two zip ties and looped them through the ventilation holes on the back of the TV. I pulled them tight, and the light is very solidly in place. It does, of course, block some of the ventilation holes, but being so far from the wall, I assume that it won't be a problem. I'd think the TV would get much hotter on a low-profile mount than with the current setup.

From what I've read (and I read most/all of that thread), the only thing you can trust is flourescents with a CRI of 90 or above. Anything else (LED, rope light, incandescent, flourescent with a CRI < 90) can't be trusted for color accuracy even if it states that it's 6500K.

I know I said I had a 6500K bulb, but I just remembered that my Lowes and Home Depot didn't have any 6500K bulbs in small sizes. I went with a 5000K bulb at 90+ CRI, which is better than a 6500K bulb at ~70 CRI (since there's little chance that a bulb with that low of a CRI is anywhere close to 6500K). 5000K might actually work better in my situation since I have an orangish wall rather than a reference gray wall, and the 5000K should do a good job offsetting that color difference. I'm thinking about wall-mounting my TV, and might break down and buy an Ideal Lume Panelight after all.

 

[ManBearPig]

Hopefully some hardware stores around here have light bulbs with those specifications. Gonna check tomorrow.

Otherwise i'll end up just buying a rope light. I know that isnt ideal, but i seriously would rather not pay $120+ for 2 standard ideal lume lights. Im also going to buy a fancy remote, and this TV game is just starting to get ridiculously expensive!

 

[s44]

Most commodity CFLs these days are 82 CRI.

In theory you need 90+ for best results, but the $5 Home Depot light bulb makes a really nice difference. Sure you can improve things further with more money, but I'm not sure the backlight is the best place to spend it.