Selador Vivid forum and lensing question

[Third time replying.  Is the site having issues or just me?]

Too many variables for a worthwhile suggestion.  What is the size, color, and material of existing cyc?  Available mounting position(s)?  Top or bottom or both?  As for the demo, two units IN YOUR SPACE should be enough, and reasonable.  You wouldn't buy a car without a test drive, right?  Ten units cost more than many cars.  If your vendor won't oblige, find another dealer.

I appreciate the thoughts Derek but that wasn't really what I was asking about. Two units is totally doable, and my vendor has already had me demo one, but my concern is figuring out which units to demo. I mean, there's 4 different sizes and dozens of lens options. I don't expect anyone on a forum (though I was hoping someone from ETC Selador would reply directly) to be able to give me an answer, but I was looking more for a recommendation of what process to go through to make decisions - like which units I should demo.

Mark,

Some testing has been carried out on the best ways to achieve a good cyc wash.

Take a look at this document for some pointers.

http://www.etcconnect.com/docs/docs_downloads/techdocs/AN115_Selador_Cyc_App_Note.pdf

Hope this helps you make your decision

Graham

I just this morning was pricing the Vivid-R and had much the same thoughts.

The only true test is going to be bringing in about half a cyc's set of fixtures and try them side by side with your existing T3's.  Plus a complete set of the available lenses as well as required hanging hardware to try single set fixtures vs. double hung. I would insist that your dealer provide this as part of the demo, as a single 10" fixture doesn't give you enough info. to make an intelligent choice, as you have discovered.

I would go for the 63" if only as it saves some weight in hanging hardware as well as fewer connections for DMX and power.  The caveat is if you are planning to use the fixtures in other configurations other then the cyc, then I could see more and smaller fixtures. 

Steve B.

While we are on the subject of lenses, I have a suggestion for ETC.

I have a combination of Fire and Ice fixtures. Because I do not have the clearance over the Cyc that is suggested in the testing above, I cannot aim from above to get a vertical strip of light. Causing the vertical physically makes it so that you only need the one lens of whatever horizontal degree you need. This keeps the light output high.

With my limitations I am left with only double lensing or buying a fleet of Fire and Ice combos to cover the cyc. And since I don't want to take the dimming hit from double lensing, I will end up buying as many combos as it will take (after nine pairs I am still short two pair, darn it).

If double lensing is reducing output so badly, what are the possibilities of making a single lens with both a specific horizontal and vertical dimension? Instead of a fan of raised triangles, you have small pyramids of the two different angles? It may not even be possible (just a wacky theory) and I know this would cause extra work on ETC's end because people would have to give you so many differing combos of 40 deg horiz. with 60 deg vertical, 30 deg with 30 deg, etc. But in my mind this lensing ability would add an immense amount of versatility to these instruments - keep the full brightness in just the area you wish it to be.

I would then be tempted to use Seladors as my primary lighting. But I have tested them in the tight distances in my venue and they just don't cover enough. Plus trying to aim a 21" or wider Selador ( getting a physically wider beam so you only have to lens what you need vertically) into a specific area gets cumbersome.

But I would use 21" (no wider) to light areas if I got the full output of the light I can get through a single lens at this time.

Small acrylic pyramids to scatter the light?

Rick

Rick, I think your hypothesis: "If double lensing is reducing output so badly..." is flawed. I don't think double lenses is the problem--it's more a matter of distribution.  See the thread Selador lenses: "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."  The amount of light lost through the lens is almost insignificant--I believe I've heard a figure of 2% loss for each surface, so your "pyramid" lens is not really saving that much over two "triangle" lenses at 90° to each other.

Rick, I think your hypothesis: "If double lensing is reducing output so badly..." is flawed. I don't think double lenses is the problem--it's more a matter of distribution.  See the thread Selador lenses: "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."  The amount of light lost through the lens is almost insignificant--I believe I've heard a figure of 2% loss for each surface, so your "pyramid" lens is not really saving that much over two "triangle" lenses at 90° to each other.

I can only comment on what I have witnessed myself. I have tested double lensing and only tried to widen the beam slightly with the secondary lens. Tying it to the example you stated, I didn't try to spread the paint much farther than I already had. It was more than a 2% drop, and easily seen. And once I saw how much of these bright new colors I had dimmed down, I did not want to give up what I get from a single lens (heh). So maybe "noticeably" is a better term, if "badly" offends. For me, it was bad to mute those beautiful colors at all.

Like I stated, my pet theory about combining the two angles in a single lens may be flawed and have no basis in physics. But even the cyc wash document on ETC's sight talks about this double lensing light loss which is why they suggest having the instruments almost directly above - so that physically you create the vertical and you only have to install a horizontal lens. If loss was only 2%, it would be a non-issue. I have no real complaints. I am pro ETC.

So it is not really a hypothesis. However my suggestion may still be a pipe dream.

You never know 'til you ask.  =)