Selador lenses

According to the cut sheet, lenses CAN be used in conjunction with one another.

There's a neat Excel workbook at

http://www.etcconnect.com/docs/docs_downloads/techdocs/Selador-Lens-Photometrics.xls .

I'm seeing the whole Selador line tomorrow here in Las Vegas, so if you have any specific questions you'd like me to ask, lemme know.

That is a sweet a** spreadsheet.  I had never seen it before, thanks!  I am a bit disappointed it doesn't include the 20 and 30 lenses seeing how the 30 is what I think I would use the most.  It also appears to be old, as it contains the data for the Vivid (with K2 LEDs) and not the Vivid-R (with Rebel LEDs), but still very useful.

One question I have is, are 7 LEDs too much?  Yes it gives you much better quality light, especially on skin.  But, what if you are not ever using it to light actors' faces?  After a comment from someone, I was pondering this.  If two different units each have 40 LED arrays, one is the x7 system and one is RGB or RGBA,  there are going to be more of each individual color LEDs in the RGB.  So if you want a simple red color, you put the red up to full on each unit, the RGB unit going to be brighter because there are more red LEDs.  I know I am vastly over simplifying, but you get the idea, right?  Maybe the x7 system is just over complicating things to the point that it is hurting more than helping if you are not planning to ever use the LEDs as key light.

As for your demo tomorrow, I would love to hear how much intensity you actually lose when shooting through one and two lenses.

Thanks,

-Tim

Tim, having tested them out on our Cyc, I don't think the Vivid has any weaknesses compared to a typical RGBA or RGBW color mixing LED system. If you're looking at the Vivids I'm not sure you'd normally be looking at white washes (key lights) anyway, that's more the Lustre or Palette's thing. But having seen RGBW and RGBA LED units on our Cyc, they don't provide as much real range in color mixing. Closer to the few dozen distinct colors a typical RGB incandescent sytem will get you. The Vivids don't have as much punch if you're only using one set of colors, say, all red - but you're usually not. A good solid red will have the Red LEDs, the Amber LEDs and the Purple LEDs all running to add into the mix and give you a good punch, and you get way more possible colors to mix through that are clearer and more distinct.

Now, if you're looking at something like architectural use or anything where you might only be looking to mix 5 or 6 primary and secondary colors or whatever, I could see your point. You'll get more punch per watt in the pure colors if you've got 1/3 of the LEDs all on full. But for my mind, whether or not you're hitting actors' faces, having a greater range of mixing capabilities more than makes up for any lack of punch in the pure red or blue range or whatnot.

Also, in my demoing one single 11" unit, it held up to a standard 1kw far cyc unit in punch in everything except the very red/amber range, and was only probably 10-15% dimmer in pure reds/ambers compared to a gelled incandescent. On the other hand it blew away the 1kw far cyc in the cool ranges.

The lenses: I couldn't detect any perceivable difference in just sheer light loss; the wider lenses of course are spreading it out over a greater area and I wasn' t measuring with tools precise enough to calculate any loss.

Xander said:

... If two different units each have 40 LED arrays, one is the x7 system and one is RGB or RGBA,  there are going to be more of each individual color LEDs in the RGB.  So if you want a simple red color, you put the red up to full on each unit, the RGB unit going to be brighter because there are more red LEDs.  I know I am vastly over simplifying, but you get the idea, right?  Maybe the x7 system is just over complicating things to the point that it is hurting more than helping if you are not planning to ever use the LEDs as key light. ...

Your point would hold true IF you were planning on only ever using red, blue, or green, but most (all) lighting designers expect (demand) a color mixing fixture to be able to produce every color made by Rosco, Lee, Gam, and Apollo.  In striplights, we found that red and green can make amber, but a fourth circuit of dedicated amber is better.  Same concept.  Look at the color wheel, somewhere on ETC's site, comparing the RGB colors possible versus X7 colors.

Blackfaer said:

...The lenses: I couldn't detect any perceivable difference in just sheer light loss; the wider lenses of course are spreading it out over a greater area and I wasn' t measuring with tools precise enough to calculate any loss.

I concur.  It's next to impossible to distinguish light lost through the lens versus light being spread over a larger area.  I use this analogy:  Say you have one "gallon" of light.  That's 231 cubic inches of liquid.  You can distribute that as 15"x15" one inch deep; or 15"x30" 1/2" deep; or 30"x30" 1/4" deep, but it's all the same amount.

There's a lot of voodoo and misinformation involved when discussing the brightness of any LED.  In the demo, a Vivid-Fire unit mixing R27 appeared slightly brighter than a 750W S4-PAR MFL with R27, and a Vivid-Ice unit mixing R80 appeared MUCH brighter than a 750W S4-PAR MFL with R80, but the colors were different, and it wasn't solely intensity.  Metamerism comes into play.  I don't think the fact that an individual LED has a dominant wavelength will ever not be a factor, whether one uses three or seven colors.

To answer one of your earlier questions:  When using a horizontal spread lens, the vertical distribution does not change.  It's much like putting R104 on a conventional fixture, except that you get a choice of 20,30,40,50,60,70, or 80 degrees of spread.  Using a 40H and 40V does make a square, albeit a slightly soft-edged one.  I've never had good results just slapping a piece of R104 in front of an LED, but I was impressed with these lenses.  Certainly much better than the extra pieces of hardware and glass strips used by another manufacturer.

Two negatives about the fixtures:

1) Would it have been so hard to add a power out, so that fixtures could be daisy-chained?

2) Difficult, if not impossible to find on the rental market, although with time and user demand that could change.  But there are products from at least two manufacturers I would expect to find in almost any major city.

Hope this helps.  I typed it twice, as the forum ate my first reply.

Xander - the point of X7 system is that you really don't need to use a single LED color to do anything.  If you want red - you can use red and red orange. This is especially true in the blue. Just one color of blue LED is fairly dull in rendering a look. The X7 system allows you to add Blue and Indigo together - add a bit of red or cyan. This allows you to craft a blue rather than just use the very narrow wavelength of one LED.

The X7 system is not about "broad strokes" but about the subtlety you can craft in the colors. We are producing a video of the demo that Derek saw last week which offers a good description of that concept. We are going to be having demos all over the country soon enough - look to our website for more information.

Xander - the point of X7 system is that you really don't need to use a single LED color to do anything.  If you want red - you can use red and red orange. This is especially true in the blue. Just one color of blue LED is fairly dull in rendering a look. The X7 system allows you to add Blue and Indigo together - add a bit of red or cyan. This allows you to craft a blue rather than just use the very narrow wavelength of one LED.

The X7 system is not about "broad strokes" but about the subtlety you can craft in the colors. We are producing a video of the demo that Derek saw last week which offers a good description of that concept. We are going to be having demos all over the country soon enough - look to our website for more information.