Observation on a focusing bezel

[monanza]

Hello,

I was playing around with a (pretty old) 3D Mag (*edit*) trying to get the tightest beam focus possible with an LedCorp PS3 HD luxeon lamp. I noticed that the reflector setting for tightest focus changes with the distance of the flashlight from the target spot. The change is small and I observe the same behavior with a Xenon replacement bulb (in my other pretty old 3D Mag). I had always assumed that the Mag's reflector was parabolic and had a fixed focal point so what gives? Is this a manufacturing tolerance issue or is it a fundamental property of the reflector?

My brain feels a little like jelly this evening so I opted to cop out and ask the CPF community (rather than think it through).

Cheers.

PS Isn't it funny how more pleasure is derived from modifying the Mag lights in the simplest ways rather than using them stock? This surely speaks to their ailing technology. Speaking of mods does anyone know if any of the Carley reflectors can be made to fit the Mag? Or better yet is there any hope for a dimpled or textured reflector from a third party? I know of Mag's refusal (disdain?) of third party replacement parts.

 

[PlayboyJoeShmoe]

Yes indeed there is some albeit slight difference in focus at distances... but I don't generally note it.

Modding M*gs is the only way to go. Best mod I have found for 2cell and 3cell M*gs is the M*gnum St*r Xenons. I have 2 2cells and 1 3cell bulbs and they make tight bright beams. They still won't flood very good.

I'm one of the guys that M*g basically told to Eff off.

I read something in another thread about the Krylon treatment. I THINK it means lightly fogging the reflector with probably clear spray paint. Someone will almost surely clear this up. I would sacrifice a M*g for this!

 

[Illuminated]

Monanza,

I'd also like to learn more about the Carley reflectors, also.

Working with what you already have, though, you might try something that Lambda came up with (excellent idea Kevin!) to add texture to your existing reflector.

It's kind of like adding a few layers of light overspray using clear coat enamel (Kevin used Krylon - I used Ace HDW house brand).

Very short blasts from about an arm's length will do it. I had the best results by letting things dry a bit between applications, and I did this for 3 or 4 "dustings" to build up some texture. If it looks wet, it's probably a little too heavy an application.

After letting the last coat dry well, I added one last coat, just barely heavy enough to "wet" the surface and the frosted look became very clear and shiny, but you could see the texture.

As for tips on technique, think "dry" for building up the texture. I seemed to notice that spraying from closer distances required extremely short blasts to try to keep from getting a wet coat, and this eventually yielded texture more like the orange peel effect (fairly coarse texture).

Spraying from longer distances yielded a finer texture (like overspray - not like spattering) and yielded a finer texture overall.

You can experiment with things a bit, and get different results. I did an old "wag" reflector and got some rather coarse orange peel type texture, roughly similar to a PT40 textured reflector, with similar beam results.

I did the smooth "narrow beam" PT reflector and aimed for a finer texture, and got decent results. The modified PT reflector yielded a tighter and smoother spot than the PT textured reflector.

The reflectors are cheap enough, so it's probably worth th risk to try it, or at least for me it was.

None of these so far yielded what would be considered perfect beams, though they were notable improvements.

Thanks again to Lambda for sharing his secret with us!

John

[EDIT: I somehow posted this under the wrong topic, but it sort of applies here - John]

[2nd EDIT - I intend to try this on other "wag" reflectors using HIGH TEMPERTURE clear coat that I've seen in automotive stores, for more heat resistance when using higher wattage lamps - John]

 

[arioch]

Illuminated:

1.)Does this reflector treatment decrease apparent light output?

2.)Is the result similar to the WriteRight lens treatment, or is it comparing apples and oranges?

3.)About how long did it take you to complete the treatment (including drying time)?

Your posting looked interesting, and I'm thinking about trying it out...

 

[monanza]

Hey thanks. I had read Lambda's post, was intrigued by it, and promptly forgot all about it

. I think I'll give it a try.

The various Mag (*edit*) mods that the members have come up with make it almost worth it to buy new Mags just for the pleasure of seeing the improvement in light output and quality first hand.

PJS, I use the star Magnum (*edit*) xenon as well. Dramatic improvement. I was considering the Krypton rechargeable from Carley. Have you tried them? I don't know how well they will work with alkalines but the wattage is considerably higher on these babies.

Cheers and thanks again.

 

[Illuminated]

Arioch,

1) Couldn't really detect a reduction in light output on rudimentary wall test using calibrated eyeballs.

2) The only Wag reflector I've done so far had a coarser orange peel texture and produced a beam very much like the PT40 textured reflector, especially in the corona. When I switched heads on the same light to one with stock reflector and WriteRight, I'd have to say that the beam and corona was smoother overall than with my modified reflector. (Tested using same calibrated eyeballs)

I plan on doing another with finer texturing as my time allows.

3) Total process time was about two full days. Three, maybe four dustings with about an hour between, plus a final wet coat a couple of hours after the last dusting. I allowed at least a full 24 hours drying time - maybe more, because the clear tends to stay soft for a good while, even after it feels (and smells) dry. Otherwise, it'll likely stick to your lens if you leave it on for long, especially with the poly lens.

These reflectors are relatively inexpensive to replace, so it's not a big risk if you mess one up. You might even use something else to practice on for developing a good technique, like maybe the separate halves of a plastic easter egg, or whatever else you can find. Just hold them up to the light at an angle so you can see the texturing. I took a chance on mine because it was very old (but O.K.), and I have more on order.

Remember, I was using my calibrated eyeballs for evaluation, so your mileage (and perceived improvement) will likely vary.

IMO it was definitely an improvement, and although I wouldn't say it's the perfect solution, it is certainly inexpensive enough to do.

I'll be doing more of them and will hopefully find the best degree of texturing to provide the best results possible.

I'm anxious to see someone try this trick and use one of JB's high-output 4-LED PR-based creations. I suspect it would be something like a Turtlelite II only brighter (like Turtlelite IV!?)

Good Luck!

John