Focusing FM Bi-Pin/1185 combo in KT4 head

[ShineOnYouCrazyDiamond]

What does the ideal focus for a WA1185 in a KT4 head look like

I have searched and found tidbits here and there but not the answers I need on this question.

When you hit the focal point of the parobica arc of the reflector does this lamp always look like an elongated egg? I know that it is a long coil (compared to say a WA1111) and the MN15/16 bulbs with those long arced coils produce a rounded out oval egg shapped spot.

I spent over an hour last night working on the beam and at it's tightest point the spot is very bright but also very wide at the same time - it's like you have to rotate it to either see a horizontal or vertical spread but not much spread in the perpendicular direction.

So if the focal point of the reflector produces a thin line beam - will a nicer arc with less spill be produced by a little above or a little below that reflectors focal point. The beam starts to round out and doughnut hole the more you move it in either direction - and I just have to assume more light is lost to the spill when it's not in focus.

I did some measuring of the few Surefire assemblies I have with a caliper and the MN15 and MN16 measure around 22.3mm from base to top of coil where the N1 meaures at around 22.5mm and we know the N1 has a razor tight beam. So I feel that 22.5 may be the ideal focus point and Surefire pulls the coil back just a touch to give a bigger spot on the MN lamps.

I also measured out a bunch of different LF assemblies and they are all over the place - latelly the assemblies I have been getting from the are pretty bad. Coils are not horizontal but instead angled down to one side, hotspots are not centered and the light looks like a comet (and this is with the M6 and M6R mostly) - I'm getting a bit fed up for the price QA seems to be lacking.

 

[ShineOnYouCrazyDiamond]

Wow - not one reply? Still looking for some input.

 

[Dioni]

And what is excatly your question?

As you said, the 1185 coill is too long compared to other bulbs and this WILL make some artifact in the beam, above all in the KT4.

Maybe, the ideal focus to me is not to you. I have used the 1185 in my M6 with its Kt4, and I set it as higher hotspot definition as I can, however this resulted in a long oval beam too.

Cheers, :thumbsup:
Dioni

 

[ShineOnYouCrazyDiamond]

;)

And what is excatly your question?

This......

When you hit the focal point of the parobica arc of the reflector does this lamp always look like an elongated egg?

Since you are basically agreeing with what I said regarding shape and size I guess the question becomes a rhetorical one - was just hoping to get some more people either agreeing that is that best that can be done - or surprising me and giving me miraculous insight. ;)

Thx.

 

[Painful Chafe]

Hey Shineon, you should have kept that T20C2. Now that ha a nice beam with the OP. :wave:
I sold it too. Loved it but need to fund a MAG project and I have a Olight M21
on the way soon.
Good luck with your build

 

[jslappa]

I have put together quite a few M6/M6R/Megalennium projects and I have never been able to get the hot spot to be anywhere near perfect, like some of my LED lights.

With the 1185 bulbs, keep in mind that, in addition to raising and lowering the bulb, you can also bend the bulb left and right. In the end, I came to the conclusion that the filament's shape was most likely the culprit. If the filament was in the shape of a circle, i might be able to focus it to a nice tight spot.

Good luck.

 

[Dioni]

A question came to my mind:

and if the filament of the bulb was in vertical position? what would happen on beam?
:thinking:

 

[ShineOnYouCrazyDiamond]

Hey Shineon, you should have kept that T20C2. Now that ha a nice beam with the OP. :wave:
I sold it too. Loved it but need to fund a MAG project and I have a Olight M21
on the way soon.
Good luck with your build

:wave: That was a while ago (well it feels like a long time ago - I have a 4month old and as such I have no sense of the passing of time anymore. Space and time have combined into one big blob of ongoing diaper changing). Wouldn't it be funny if a year from now I go full circle and start buying the light I am now looking to sell?

See Chafe - the T20C2 just wasn't enough power in your hands....... you had to go further as well.

A question came to my mind:

and if the filament of the bulb was in vertical position? what would happen on beam?
:thinking:

I had read in a thread somewher that the filament in a vertical position is not ideal for a tight spot. What it will give you is a large bright round hotspot with very little side spill.

****************

I have to say that focusing the FM3X head because of the smooth reflector can by pretty fugly indoors. I actually didn't realize even with a 20-30 foot shot across the room how intense my hotspot was because there is just so much spill with this bulb/reflector combo. When I went outside and shot it into the sky I had this tiny super bright laser beam spot.

The throw on this thing is incredible! The spill does a good job imlluminating everything around the hotspot and the hotspot was amazing at about 150 yards.

Now all we need is better battery technology so I can get more than 10-15 minutes runtime off 3-IMR18650s - but this will definitely remain the WOW factor light.

I was a bit bummed that my AW softstart just died on me last night..... supposed to be good up to 75W and this combo fall in between 60-65W. I don't think I let it's smoke out because no smell - switch just died. In contact with Lighthound now for a replacement.

 

[jslappa]

I can't remember where I saw them (M6 shootout DM51 did) or a LuxLuthor thread, but I saw a bulb with the filament in a vertical position. I want to say it was an Osram bulb. Could have been in a M*G thread too I suppose.

 

[FlashKat]

Here is the DM51 http://www.candlepowerforums.com/vb/showthread.php?t=230857

I can't remember where I saw them (M6 shootout DM51 did) or a LuxLuthor thread, but I saw a bulb with the filament in a vertical position. I want to say it was an Osram bulb. Could have been in a M*G thread too I suppose.

 

[Dioni]

There is not axial bulb in DM51 shootout. I'll looking for some beamshot.

 

[bigchelis]

I had the FM Bi-pin kit with WA 1185 in a KT-4 bezel and from what I recall it had a nice balanced beam.

One thing that I just experienced that can make it out of focus and fugly was the lamp not dropping in all the way into the bi-pin adapter. I had the FM 1909 lamp and Bi-pin kit and after MrGman cut the legs off the lamp it was a pleasant and even beam. Prior there was a 2mm gap between the lamp and the bi-pin kit, but now it sits flush with the bi-pin kit.

Have you solved your fugly beam issue?

Before you cut the legs off, try moving it upwards a couple mm and see how it looks.

bigC

 

[ShineOnYouCrazyDiamond]

Have you solved your fugly beam issue?

Before you cut the legs off, try moving it upwards a couple mm and see how it looks.

bigC

I think I have - thanks. I did put the FM holder into a KT4 head and much nicer looking beam. It was the FM3X (as mentioned above) which was producing the ugly beam inside with the smooth reflector - but outside it is WOW!!