Has anyone used either of these Cree optics?

[widmer]

Hello, I'm widmer from www.reefcentral.com forums. A lot of us are working with high output LEDs like the Cree XR-E and XP-G to light our aquariums. Most aren't concerned much with optics, and if anything, they may use 60 degree optics to narrow the light a little bit.

However, I've got a unique application where I want to make a fixture which essentially acts like 18 XR-E flashlights put together. I had previously bought these 6 degree optics from LED Supply:

http://ledsupply.com/optx.php
However, they gave me a very poor quality beam which is filled with artifacts and has a really intense thin ring around the perimeter.

So I'd like to try one of these:

http://ledsupply.com/247-10-lens.php or

http://ledsupply.com/10199.php

And I'm really looking for a nice clean beam without that ugly intense ring around the outside etc. Does anyone have any experience with either of these?

THANKS

 

[Doh!Nut]

The 1st option (with the white holder) is pretty widely used, I have a couple at home and have been pleased with the beam, not least because the holder snaps nicely on the Cree XR-E ring.

Nick

 

[widmer]

Thanks for your input! I have no idea what you flashlight guys are doing, so it was kind of a shot in the dark for me to post here.

Would you be able to comment on the quality of the beam, as far as whether there is an ugly ring at the outside of it, or if the spread isn't symmetrical etc?

 

[dom]

Hi Widmar:welcome:
Are you looking for an even flood beam or a spot/flood beam.
The optics you are looking at all give spot/flood.

A flood beam is accomplished using an aspheric lens,and adjustment
of the distance between the lens and LED will vary the flood width.

Cheers
Dom

 

[widmer]

Thanks for your help as well.

What I'm looking for ideally is an even spot. Meaning, I'd like to cast a beam 6 feet, which is 12 inches in diameter. I would prefer that the beam is homogeneously bright (ie not extremely bright at the center inch and not-so-bright anywhere else).

I've only got store credit at LEDSupply, so it's between the two options I've posted for me.

I'm leaning toward the Cree brand lenses rather than the Carlco brand, due to both the above recommendation, and according to Cree's data sheet, they claim that the spot is evenly bright throughout. Any opionion as far as these two are concerned?

 

[dom]

Hi Widmer
I have (since i checked) both the Cree and Carclo you linked to.
You would be right in choosing the Cree.

Has been and still is a popular optic around here.

I just tried some wall shots with both optics.

The Cree at 6ft is approx 16" -nice beam with minor artifacts -no big halo or ring - slight hotspot blending well into the rest of the beam.

The Carclo (10199) projects the die of the LED with lots of artifacts and aberrations.
(Note: The Carclo 10200 is one of the nicest optics i've used. No noticeable spot and slightly wider beam than the Cree at 6ft)

Cheers
Dom

 

[yellow]

the cree optic (w. white holder) is the best optic to use with the XR-E,
even better - but also much more expensive - is Sandwich shoppe's 19 mm reflector
http://theledguy.chainreactionweb.com/popup_image.php?pID=677&image=0
(the one on the left)


this here might be of interest:
I have posted it several times already, sorry if anyone gets bored with it.
Goal was/is to show how the beam extends, not a brightness comparison of the focusing devices
(even when there also is some brightness comparison)
the cree optic was the only optic I considered useful enough to keep for the XR-E, all the other got kicked away.
The Fraen reflector is crap, but cheap
SS 19 mm still the best in that size class.
Main beam of 19mm and Cree optic are almost the same, but - imho - the optic (NO optic) gives nothing of a useful spill.
Thats where reflectors shine. Personal, subjective view of course.

PS: no cree ring with Sandwich Shoppe reflectors, optic - afair - also not.
the black shadows are from the rubber band that temporarily holds the reflectors in place

 

[widmer]

Not sure if my reply posted, so here it is again.

Thanks for the GREAT advice guys, it's exactly what I came here for.

dom: That's just what I needed to hear. Thank you for diverting me from the carlco, since I can't have ugly uneven light.

yellow: Great work! Just to be sure, is the Cree the one that's across the top? And what are the distances it's projecting from in each picture? Finally, do you mind if I link to this pic from my aquarium forum? I'm sure a lot of aquarists would like to see it.