Welcome to our community

Be a part of something great, join today!

Log in
  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

LED Lights

Mark Collins

Mark Collins

Well-known member
Joined
Oct 16, 2009
Messages
431
Reaction score
0
Points
0
Location
Toronto, On
Hello!

Right now I'm currently a media arts student at Sheridan College in Toronto, and I'm looking at working with LED lights to see how they stack up against the standard tungsten, HMI or fluorescent bulbs.

I'm just wondering if anyone has worked with LED lights, and if so, is there anything I should be watching for, or what are your opinions on them?

The camera I'm shooting them with is the EX1 as well.
 
so far i personally have not been too impressed with what is available so far. to sum it up the ratio of expense to output is just too high. i carry a few for specialty applications such as boosting the light from a computer screen or doing the car dash light gag at night, or an eye light, but for general lighting just not enough "poop." every application, however, is different and you might find them very useful for something specific. id like the prices to come down to a realistic level. for example, suggested rental rate for the 'lightpanel' 2-light kit is $300/day. there just is no realistic way i can charge that much for a kit that is practically a throw-in. one of the consequences to being compact is they just dont appear to be worth much rental wise.
 
Last edited:
The Cool Lights LED 600 is a well appreciated fixture with great output--about equivalent to a 650w fresnel. You can check them out here:

http://www.coollights.biz/clled600-panel-p-114.html

Many on this site have and use them. Here's a couple of threads where they were discussed:

http://www.reduser.net/forum/showthread.php?t=36727

http://www.reduser.net/forum/showthread.php?t=29267

As far as how they compare to fluorescent an LED unit will be harder than fluorescent in output but shadow rendering will be different and not well defined like with a single point light source like an HMI or tungsten based unit. So think of it as something between a true hard light like a fresnel and a soft source like fluorescent or other diffused light.
 
I used the Ledz Brute16 on a couple of recent shoots.

http://www.led-z.com/brute16.htm

On one shoot I used it for a flashlight effect on the subject, carrying it around with me as the subject moved around. In this case, its small size and low/no heat was necessary, and it put out enough light, which is something I was worried about with other mobile solutions.

On another shoot, it was the only daylight colored source in a sea of tungsten Source4s. The color mix was fantastic, and the light spread really well with haze.

For the cost to output ratio, LEDs suck. That aside, I really like LEDs and I hope they start getting much cheaper and much bigger - imagine having a 2.5k/4k equivalent that could run off of your typical Edison output!

Also, for RED work, it's great to have a 5600k source that isn't a gelled tungsten (which would make the light lose stops).

Personally, my only gripe with LEDs is cost. Aside from that, they're awesome!
 
Eileen, what I was referring to is the comment made in another thread about HMI bulbs changing lumins with age and how important it is to measure, then make adjustments, for the actual kelvin being produced by each light fixture. If you have a number of fixtures on set, that can be time consuming--I'm assuming. Apparently this is not an issue one has with tungston. What is the labor time factor in making these adjustments, or are the comments not that big of a concern.

Again, thanks for all your help
 
i wish cool lights, and their customers, all the best but i personally can never buy or promote their products.
 
onsighthawaii said:
i wish cool lights, and their customers, all the best but i personally can never buy or promote their products.
Click to expand...

Thats fine, we will do it for you.

Have bought and will promote.
 
I'd say so ya.

It's a lot easier to make remarks like that without using your real name. Plus it's a rule in this forum.
 
I just went to the coollights website to check out the lamps. For the CL LED600 they list a CRI of 80 for the 5600K and 85 for the 3200K lamps. Isn't this a bit low for colour-critical lighting situations such as film/digital cinema?
 
Now there's a question without an easy answer.

I wrote a couple of articles this year on not only the benefits of LEDs but also the shortcomings and the stage of where we are at with them:

http://www.coollights.biz/wordpress/archives/199

and

http://www.coollights.biz/wordpress/archives/72

To boil it down though, yes its a common issue with LED fixtures in general. LEDs, especially single, mono-color daylight ones have CRI issues at this point so its something every manufacturer of an LED fixture for film/media use has to deal with in some way. There are several ways to handle it, the most common being:

1). Use the daylight LEDs and add more magenta to the LED to filter out the extra green produced in their spectrum. Fluorescent tubes have been doing this for quite a while to make their spectrum suitable for photographic use and increase their CRI (Kino reports 95 on their tubes, Cool Lights is 90 on ours--see my articles for why we didn't go to 95). So you add magenta either internally on the LED or externally by way of minus green filter--either has the same effect. By the way, it often isn't an issue if you aren't mixing with other kinds of existing light and using such a fixture in a controlled situation. The reason for this being the white balance in your camera can correct not only whats going on the blue/red axis of color temperature and make what is white supposed to be white but also along the magenta/green axis as well which ends up being indirectly a good reference of CRI. If magenta / green is balanced well, you often find a light like that has a high CRI. When using real film you have no white balance and you therefore have no choice and must apply minus green to an flo or LED light of "offending" CRI.

2). Use two colors of LEDs in the panel -- one high and well above normal daylight and one low, just below normal tungsten range. Have a dimmer arrangement to dim independently each color temp so you can adjust to the color temperature of your choice. The two colors mixing together will produce a higher CRI light that doesn't require other filtering. There are several manufacturers using this approach right now and its probably the best way, IMO, to increase CRI and still keep the fixture economical.

3). Use RGB LEDs to output whatever color temperature of white you want and even single wavelength colors like red, blue, etc. This also makes a good approximation of daylight thanks to the 3 single wavelength colors making up the spectrum. Not unlike the bi-color approach of method 2 above which is more than adequate to output a usable spectrum. RGB's an expensive way to go though and RGB LEDs are relatively weak compared to other kinds in output. You'll also need a microprocessor and user interface to handle the color mixing as 3 manual dimmers would be too complex to deal with. That makes it easier to dial in the correct color output you want.

Thus, approach 2 and 3 are more expensive. Approach 1 was the route we took for our first products to keep the cost affordable. Approach 2 will be what we take in next generation fixtures. We'll still make the mono-color daylight panel like the LED 256 and 600 though because they are so well appreciated as long as you know the limitations and you use it accordingly.

That's also why we include a convenient filter panel set with the LED 600 and 256. It makes up for the shortcomings in the LED's spectral output and increases the CRI to a very usable range.

Let me know if you have other questions. Hope this helps.
 
onsighthawaii said:
why? does it make any difference what so ever? is my opinion somehow less valid?
Click to expand...

Of course it does. Without real names it's difficult to know if posters have ulterior motives.

Doesn't eliminate the risk as you could just lie about your name, but you could be the owner of the competition for all we know! :wink5:

This is a real name forum.

P.S. I know a lot of people using Cool Lights who swear by them (not at them.)
 
I swear at all of my gear.... including my coollights and especially my RED. ( although the RED will boot up slower if you repeatedly say " come on bitch " to it while it's booting up )

Studies have shown that if you swear at inanimate objects without touching them, they will last just as long as if you don't swear at them.... but with the added benefit of the swearer will letting off some pent up steam. Resulting in a more creative environment.

And don't get me started on house plants.... they love swearing and actually become healthier plants. Google it if you don't believe me.
 
You must log in or register to reply here.
Back
Top