John Saunders
January 20th, 2010, 10:32 AM
So I am thinking about making a large led ring light since they are so expensive to buy. The litepanels cinema one is like $8000 and the mini is $2300. Now I know I will not get the same performance as the cinema (it's a nice light) but I think I can match or do a little better than the mini. I plan to have about 120 broken up into x6 20 led rings. I wouldn't dim them because I am worried about flicker even with PWM so I plan on turning the rings on one at a time for some brightness control. I am planning on spending $300-500 for the leds, cuircut boards, custom metal enclosure and the like.
My first step was to try and pick between the 4 leds I found that I thought would work the best. All of them are about $0.98 each and were rated for about the same output. I set them up one at a time 6 inches away from a color chart and a few colored markers (wanted to see how they rendered the colors). They were all powered at 3.5 VDC that I brought down from a 6VDC 180ma power supply with an adjustable voltage regulator. I then took a picture of each one with a 85mm 1.8 canon lens at 10th of a sec. One picture with the daylight WB setting (I think its 5200k even though the chart I was holding says 5600k) and then another picture with the kelvins set to what the led spec sheet rated them at.
***If you want to download the images they are here Ledtest (http://www.cgllc.com/ledtest/)
All of the pictures:
http://cgllc.com/ledtest/ledtestcomblowres.jpg
What I think are the 2 best (the kingbrights):
http://cgllc.com/ledtest/Kingbrightcomp.jpg
at 100%:
http://cgllc.com/ledtest/Kingbrightcompclose.jpg
Comparing the White, Black, and 50% Grey from Photoshop:
http://cgllc.com/ledtest/Kingbrightcompclosebwg.jpg
So I think I like the 6000K the best but it will need more of an orange gel to use it with other tungsten lights.
Please let me know what you thoughts are and if I should have done the test differently. Thanks.
My first step was to try and pick between the 4 leds I found that I thought would work the best. All of them are about $0.98 each and were rated for about the same output. I set them up one at a time 6 inches away from a color chart and a few colored markers (wanted to see how they rendered the colors). They were all powered at 3.5 VDC that I brought down from a 6VDC 180ma power supply with an adjustable voltage regulator. I then took a picture of each one with a 85mm 1.8 canon lens at 10th of a sec. One picture with the daylight WB setting (I think its 5200k even though the chart I was holding says 5600k) and then another picture with the kelvins set to what the led spec sheet rated them at.
***If you want to download the images they are here Ledtest (http://www.cgllc.com/ledtest/)
All of the pictures:
http://cgllc.com/ledtest/ledtestcomblowres.jpg
What I think are the 2 best (the kingbrights):
http://cgllc.com/ledtest/Kingbrightcomp.jpg
at 100%:
http://cgllc.com/ledtest/Kingbrightcompclose.jpg
Comparing the White, Black, and 50% Grey from Photoshop:
http://cgllc.com/ledtest/Kingbrightcompclosebwg.jpg
So I think I like the 6000K the best but it will need more of an orange gel to use it with other tungsten lights.
Please let me know what you thoughts are and if I should have done the test differently. Thanks.