McLux PR-T Head?

[bmstrong]

The old McLux PR-T Heads? Does anyone have the dimensions of one of these? They ran 27mm reflectors, correct? Using the same board and led, in both the Aleph 2 and the PR-T, what kind of percentile increase in brightness would I be looking at?

Thanks!

 

[Kiessling]

The PR-T uses a PR reflector which is similar but inferior to the McR-27 of the Aleph1 ... and can be replaced by this one. The front window is also inferior, but otherwise the optical characteristics are the same.

You can treat the PR-T head as an inferior Aleph1 and have thus a base for a comparison with the Aleph2.

bernhard

 

[cy]

I disagree PR-T is an inferior Aleph1. for a 5watt application. I would consider PR-T to be superior to Aleph. due to additional potting for superior heat transfer.

Plus you are not going to get much better than the fab aluminum pelican reflector.

I prefer pelican's reflector's beam to aleph1. Aleph3's beam is clearly superior to 27mm pelican reflector.

but this is personal preferance, others may see it differently.

 

[Kiessling]

I was talking about the efficacy of the photon management where the Aleph1 is clearly superior.
Don measured about 10% more performance with the McR-27 than with the PR, and the lens is better, too.
The beam characteristics of the PR and the Aleph1 reflector (McR-27) are identical, it is basically the same reflector.

On the heatsinking ... I dunno for the PR-T /ubbthreads/images/graemlins/icon3.gif ... but the PR-head has certainly more beef /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif

bernhard

 

[bmstrong]

Interesting. I really like the clean look of the PR-T, better than any other head.

>>and the lens is better, too

You should just be able to swap the new lens for the old one, correct? Same as the new reflector?

How much brighter is the McR-27 vs the McR-20, using the same engine, led and battery? Say 25% brighter? Or less? (Bigger reflector + smae interior on both lights = more brightness, correct?)

How big is the PR-T body?

Brian

 

[Chop]

The Aleph I and PR-T lenses are not interchangeable. The Aleph I has a 2mm thick lens with anti reflective coating on both sides. The PR-T has a plain thin mineral glass lense.

All other things being equal, the McR27 will get you a lux reading that is about twice as much as that of an Aleph II. I'm not necessarily saiding that you'll get more light out of the Aleph I, but you will get lots more throw, at the expense of the glorious sidespill that the Aleph II will give you.

The PR-T is also an E series compatible head and will fit on any Aleph or Surefire E series compatible body.

 

[bmstrong]

Tony:

>>the McR27 will get you a lux reading that is about twice as much as that of an Aleph II.

Moo Hoo Haa Ha. Power. Game on!

Many thanks:

>>The PR-T has a plain thin mineral glass lens

Could this be swapped for an UCL?

Are there any spec sheets online / CPF for the physical dimensions of the PR-T head? (Search turns up nada.)

Brian

 

[Chop]

I think that flashlightlens.com has a UCL for the PR lights. I believe that they have a slightly thicker version too.

I don't know about the dimensions of the PR-T, but it's a pretty straight forward design. 5 minutes with a dial caliper should get you pretty close.

 

[cy]

note that while aleph1 may have 2x higher lux than aleph2.

when I compared 27mm to 27m with aleph1 and PR-T using a DB917 TWOJ on both.

for throw PR-T was slightly better than aleph1. I just sold my L1 PR-T 917 /ubbthreads/images/graemlins/icon15.gif, so I can no longer do side by side comps.