Radion light spread

[rayn]

With the future release of the radion G4, I am wondering about light spread. The info I am seeing shows almost a 36"*36" spread per puck. If this is true, then wouldn't a a pair of the XR15w work to light a 5 foot tank? Does the dual puck models actually help with the shadowing issue that much? Maybe know ones knows yet as they are still new and not released, but it makes them more appealing if that would be the case.

 

[CJBuckeyes]

They state the max spread of the x15w g4 as 24" x 24" and the recommended as 18 x 18". If you're sticking to their recommended guideline, then even 3 wouldn't quite cut it. Depends what you're going to keep in the tank, though.

I did notice that there is no longer a discount in purchases a xr30w pro vs 2 x xr15w pro. I have two gen 3 xr30 pros, but I'd much rather have four x15w pros. This would help a lot of people with shading, as the pucks in the xr30w are too close together.

 

[mcarroll]

They state the max spread of the x15w g4 as 24" x 24" and the recommended as 18 x 18". If you're sticking to their recommended guideline, then even 3 wouldn't quite cut it. Depends what you're going to keep in the tank, though.

I did notice that there is no longer a discount in purchases a xr30w pro vs 2 x xr15w pro. I have two gen 3 xr30 pros, but I'd much rather have four x15w pros. This would help a lot of people with shading, as the pucks in the xr30w are too close together.

Boom. Well said.

 

[rayn]

So 4 of the xr15 would give better spread and less shadowing then a pair of xr30.

Dang. 800 for a pair vs. 650 for a single.

 

[mcarroll]

So 4 of the xr15 would give better spread and less shadowing then a pair of xr30.

That is correct.

Consider China shoeboxes, Primes, little Hydra's, Kessils, Razor nano's, etc...all in the same vein of mini halide imitators. Nothing wrong with that, per se. It's just a feature they all share due to similar design formats, so they all have the halide shadowing to some degree.

There's nothing unnatural about it....just a matter of what you like. At least from reading online, it seems like a lot of folks don't like the big-LED light as many of them end up complaining about it and switching...or amending the light with other fixtures.

 

[mcarroll]

The info I am seeing shows almost a 36"*36" spread per puck. If this is true, then

Yes, coverage on the tank from side to side will be better AND that brutal peak in the center gets less brutal.

But, then people will be wasting even more power by trying to make one fixture cover too large an area.

Here's a proportionally sized example of a single G3-type fixture being raised to cover a 5' x 1.5' tank:



Here's the same example with idealized "better spread" lenses:

 

[rayn]

I have the China box, hydra 26, and Kessil already. Running MH on my tank now a s having issues with them.

Shadowing I get, just don't want long dark sides.

 

[mcarroll]

A strip is arguably a better solution for that.....other than a strip (e.g. Orbit Marine Pro), you need the Kessil AP700/Razor approach where there are many well-spaced pucks. Not just two concentrated in the center.

 

[rayn]

@mcarroll

With your light spread pics there, I'm not wanting to light a entire tank with one light, but if two pucks work, why run 4?

 

[mcarroll]

Good question....more is actually better for the same reason.

With each additional fixture, shadows diminish and coverage improves, and there's less "need" to spill light.




A strip light would be more like:

 

[rayn]

Going with that, then is there a chance of getting to high a par with them overlapping? Seems a strip light gives better coverage without the overlapping.

 

[mcarroll]

There is.

Not to say you can't do the multiple puck light route and get it to work - it's just slightly more complicated.

Use a lux meter ($free app, $15 handheld...PAR meter good, but not required) to align the fixtures so the light field is fairly homogenous and so there are no super hot spots. But there will still be many more gradients of light than a strip-format light.

 

[Larry L]

With each additional fixture, shadows diminish and coverage improves, and there's less "need" to spill light.

That picture only works if you can keep moving the fixtures lower and closer to the sandbed as you add more (i.e. to make the circular spots smaller). If you're using the standard mounts (which is pretty common), your fixture is always going to be the same distance from the sandbed and will always create the same size circle, so adding more fixtures just creates more overlap. I agree that the coverage will be more even, and you can tweak the intensity so that you are not blowing things out with high PAR in the overlap areas, but it will not lessen the spillover. If you want to lessen the spillover, you can replace the 120 degree lenses with 80 degree lenses, so that they create a smaller circle with the fixture at the same height (that's what I did with my two XR15s over a 3 foot long tank).

 

[mcarroll]

That picture only works if you can keep moving the fixtures lower and closer to the sandbed

Yes, good point! You can see that difference in the size of light projections in the rough diagrams I posted.

You do have to be able to raise and lower the fixtures from one design to the next....or change the lenses if that's an option for the light you have in mind.

A little triangle math and you can make some good predictions about what you'll need in terms of height and/or lens,

Assuming 120º lenses...

...the first diagram with one light projection covering a 60" tank would have the light mounted at about 17".
...the second diagram with two fixtures covering 60" would have the fixtures mounted at about 9".
...the diagram with five fixtures getting almost all the light into an 18" wide tank would have the fixtures mounted at about 5".
...assuming the very last diagram is an Orbit Marine Pro with 60º lenses, that wold be mounted at 16"​

Maybe also worth noting that these are just example mockups to generate ideas....nobody should start drilling holes based on these numbers.