DIY Photometry testing; various McFlood reflectors

Don McLeish kindly has provided me with various McFlood reflectors for photometry testing. Shown in the photo below, left to right are an unmodified EN plated McFlood, a Beadblasted/sanded/polished McFlood [all EN removed exposing aluminum only], and finally on the right a beadblasted only [all EN removed].


Well, it looks like the Image Station folks are not cooperating anymore. Here it is courtesy of Beretta1526 who has hosted it:


I measured the relative performance of these three reflectors using the integrated photometry techniques described in the following post:
DIY photometry

Here are the results, normalized to the stock EN McFlood:
<ul type="square">
Stock: 1.00
Al polished 1.10
Bead Blast 0.84
NX05 1.20
[/list]
I really like the "beam" of the bead blasted sample. It occurred to me that if a McFlood were just painted black it would produce a similar "beam". To see how much the reflected light from the BB surface contributed to the brightness of the beam I compared the raw lux readings with the sensor looking at the source compared against the reading with the bare LED. The BB reading is exactly double the bare LED reading. Here is similar data for all reflectors/optics normalized to the bare LED reading [all are peak readings within the beam]:
<ul type="square">
Bare LED 1.00
Stock 8.9
Al polished 9.0
Bead Blast 2.0
NX05 37
[/list]
Note that in my first dataset that the Al polished performed only 10% better than the EN which is only about half of one luxeon bin grade. Previously I had obtained about 20% gain using reflective Al sheet fabricated to the approximate shape of the McFlood. The difference may be to either the degree of polish or the inherent reflectivity of the particular Al alloy. I don't know which, but I lean weakly towards the degree of polish. The Al sheet that I used previously had been purchased 12 years ago and was selected specifically for it's reflectivity. I suspect if it were possible to texture the surface of a McFlood and then vacuum deposit a reflective aluminum surface, it's performance in terms of total flux output could equal or exceed that of an NX05.

I pulled the image and put it on my website so there's no issues:

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Beretta1526 said:
I pulled the image and put it on my website so there's no issues:



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Thanks!

Doug, after reading your earlier topic, I sanded two of my three McFloods down to bare aluminum and polished them to a mirror like finish. I find that my lights are obviously brighter with the polished McFloods, so the 20% figure seemed good to me. The picture of the polished McFlood that you posted seems to show a lesser degree of polish than what I have. (The polished reflectors do, of course, show stronger "artifacts".)

Re: DIY Photometry testing; various McFlood reflec

When i finally modify a Minimag reflector to my satisfaction, could i send one to you for photometry testing and comparison to the McFlood? One thing that a focussed Minimag reflector has is a pretty bright hotspot, coupled with decent sidespill, so i'm thinking it should compare favorably to the NX-05.

Re: DIY Photometry testing; various McFlood reflec

I've been wanting to try this but hadn't gotten around to it. This is great test info, thanks for sharing.

I've also used the McFlood as an assembly jig to center luxeons when epoxying them onto the heatsink.

Re: DIY Photometry testing; various McFlood reflec

Doug,

I missed this post the first time around! /ubbthreads/images/graemlins/blush.gif /ubbthreads/images/graemlins/smile.gif Thanks!

Re: DIY Photometry testing; various McFlood reflec

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Mark_Larson said:
When i finally modify a Minimag reflector to my satisfaction, could i send one to you for photometry testing and comparison to the McFlood? One thing that a focussed Minimag reflector has is a pretty bright hotspot, coupled with decent sidespill, so i'm thinking it should compare favorably to the NX-05.

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Mark, AA Minimag to McFlood comparison data is contained in the following thread:
Click

Wow, great post. Answered my question.

New question: Can a dremel tool easily remove the plating while leaving a smooth undamaged surface? And what kind of attachment would you put on the dremel to do this if it is possible?

Thanks,
Moses

Re: DIY Photometry testing; various McFlood reflec

Thanks for the link. I see that the reflector performs better than the NX-05. Have you measured the NX-01?

Re: DIY Photometry testing; various McFlood reflec

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Mark_Larson said:
Thanks for the link. I see that the reflector performs better than the NX-05. Have you measured the NX-01?

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I don't think that I have measured an NX-01.