I have looked at this paper but have not sat down to read it in detail (to much math for late night reading). Two things strike me though. They don't actually show the results of a full PAR measurement across their 40" x 20" x20" test tank unless the charts they have are mislabeled as they show distances in mm in the charts. Also, this is an internally produced document that seems to be designed more to justify not using optics rather then as an independent test of their fixture so I take it with a grain of salt.

So that's why I am looking forward to seeing real world PAR readings over a real aquarium :biggrin:

Yeah, it's a heavy read but it's more detail than I have seen from any other LED fixture maker so far.

I'll take PAR readings on Sunday and post them here.

Cheers!

-TDF

I'm not sure how one thinks measurements done by some dude in a basement over his aquarium with a hobby PAR meter classifies as more "real world" and therefore more accurate than laboratory tests done by a manufacturer which developed the product but whatever.... I think the document gave a good idea of what to expect. The PAR test was at 19" of water depth so the need to see PAR beyond what was presented wouldn't really be needed. Follow the pattern and you get the idea.

I have to say I like this fixture, it has almost everything I've been waiting to see in a LED fixture. Sleek look, easily upgradeable\replaceable parts, good warranty, and the controllability looks awesome!

Great fixture man, looking forward to seeing how it works out for you.

joining the group to hear feedback about the fixture

Well the dude in the basement is most likely using the same Apogee quantum meter that Vertex is using, can test in various positions just like Vertex and is not trying to sell the product to anyone so I would take his results as being just as valid as Vertex's if not more. All Vertex did was set out a grid in a tank full of water and make measurements. Hardly something requiring specialized facilities or equipment or rigid scientific control.

Also, I would be happy if you can point me to the results of Vertex's test in the paper? I see two plots of areas measuring roughly 4 inches by 4 inches (100mm x 100mm). In those plots the PAR drops 30% from the center to the front and back when moving a mere 2 inches. So what would the PAR be 6 inches front and back or a full 9 inches at the front and back of an 18" wide tank? How about in a 24" wide tank? I still question vertex's design choice and that's why I am wanting to see some real world numbers over an end user's setup.

IMO Vertex's paper is a bit disingenuous. They are trying to make a case against optics and saying that the light is concentrated in a small area so that's not good. They fail to take into account (or just don't bother pointing out) that all these narrow cones overlap to give an even spread of reasonable PAR over the whole tank. I strongly suspect that the Vertex fixture will produce decent PAR in a narrow strip down the center of the tank and then will have rapid fall off as you move front or back. That's why I would like to see some independent end user tests. I'm sure most others would to.

That paper was NOT supposed to be leaked.

Albert, that paper was posted by Nicolas, Vertex Germany on a German forum back in April.

I removed it.

Some additional photos:

http://i390.photobucket.com/albums/o...D/P1010278.jpg

http://i390.photobucket.com/albums/o...D/P1010279.jpg

http://i390.photobucket.com/albums/o...D/P1010280.jpg

http://i390.photobucket.com/albums/o...D/P1010286.jpg

http://i390.photobucket.com/albums/o...D/P1010284.jpg

That paper was NOT supposed to be leaked :)

It is an unfinished product.

See comment by 'Jason' here:

http://glassbox-design.com/2010/vert...review-optics/

A full review will be released at a later date with data.

Here is a brief video of the built-in demo program:

http://www.youtube.com/watch?v=vHo7LTgkbZ4