Another question about color rendition

[Swedpat]

During some weeks I have played with my cool and warm LED-lights together and then I got a thought: when comparing cool and warm LED I find none of them to be neutral. The cool LED have a bluish tint and the warm LED a brown or beige tint. But what happens when put the beams together?
If i mix two emitters with same brightness and one has 4200 Kelvin and the other has 6000K the resulting tint must be 5100K. Actually very close to the true natural white! And yes; if I put the beams together the result really seems to be a more true white tint.

Anyone who thought about this earlier? Also I wondered about if it's possible to use a coloured reflector to adjust the tint?

Regards, Patric

 

[kramer5150]

I was playing around with this the other night...

Combining these two for ~350L OTF. The result was very pleasing... Q25A + Q5WC

 

[Bullzeyebill]

See post 130 http://www.candlepowerforums.com/vb/showthread.php?p=3085403#post3085403

Bill

 

[Swedpat]

Interesting that my thought already has been thought before!

Here are two pictures I took early this morning when compared the tints of a cool white and a neutral white to the early morning sun which shined through my kitchen window.

Fenix LD20 at turbo and Quark AA2 neutral white at high.
The lower picture shows the beams mixed together. The pictures talk by themselves.


[URL=http://img268.imageshack.us/i/tintjmfrelse002.jpg/]
[/URL]

 

[StarHalo]

Your standard cool tint LED has a wonky looking color range that starts with a sharp rise and fall right around primary blue, then a rounded hill that starts in green, peaks at yellow-green, and ends in the yellow-orange (this is why when you illuminate objects that are chartreuse/"radioactive green" and a specific shade of blue, they slightly fluoresce as if under a blacklight. Meanwhile red objects are always muted and appear to be shifted either towards orange or magenta.)

Warm LEDs are the same thing but with a small spike in the orange-red. The beam looks warmer because there's a bit more orange and red thrown in; otherwise it would be the same cool tint LED. You adjust how warm or cool the LED is by adjusting this small spike in the orange-red. This is why a lot of the custom light guys will frequently toss in a red or orange LED in with regular power LEDs, to balance out the color curve and tint.

You can use a colored reflector to adjust the tint of the hotspot, but the spill would remain the color of the LED. And you can of course tint the lens to tint the beam overall, but most flashaholics view this as heresy since you're losing lumens to the lens and reducing efficiency.

 

[DM51]

Swedpat... your pics need re-sizing to comply with Rule 3.

 

[yellow]

my main light uses a led with perfectly white tint,
so I cant imagine how mixing a cold and a warm led results



... mod Your lights with a led of a tint You like best

 

[Swedpat]

Swedpat... your pics need re-sizing to comply with Rule 3.

I am sorry if I transgressed against the rules. I thought that as long the image doesn't makes the page wider (and makes it necessary to scroll sideways) than the screen it's no problem. I will change it. I need some help though. 800x800 pixels I read in the rules. How does that compare to 68,4kB?

Regards, Patric

 

[DM51]

I thought that as long the image doesn't makes the page wider (and makes it necessary to scroll sideways) than the screen it's no problem.

If you right-click on your photos, then select "properties", you'll see they are 922 x 692 pixels. Pixels are a way of measuring the size of an image. 800 x 800 pixels is the CPF limit here, so you need to re-size yours.

 

[Swedpat]

Yes, Now I see, thanks for help. I have measured it. Hope it's not a problem the two pictures are placed together?

Regards, Patric

 

[Swedpat]

You can use a colored reflector to adjust the tint of the hotspot, but the spill would remain the color of the LED. And you can of course tint the lens to tint the beam overall, but most flashaholics view this as heresy since you're losing lumens to the lens and reducing efficiency.

Thanks for the answer. Yes, when you say it I understand that it's obvious that the spillbeam will still be (to a big part) the tint of the LED. But also I realize that it actually will be a mix of the tints, because even the spill includes partly reflected light, though not focused.

Regards, Patric