Well, I have a 2" deep reflector, I'm not familiar with your bulb but make sure it will fit through this or you'l need the 2.5 or 3"
I love em! (based on my 2")
They are very efficient and really taking all the light, artifacts and all, over a longer reflective parabola and bending it all into a tight beam with alot less artifacts.
The worst you would have (and only if you opened up focus quite a bit) is a perfect donut.
This of course assuming the following, that the bulb is centered, at the right focal length height.
I'm also not familiar with that bulb but I assume that like most Osrams it has a horizontal filimant, is sort of tall, and has a dippy doo of glass on the top.
It will definitly be a big improvement in my opinion.
I can honestly say that with an 1185 bulb (which is a round top) it casts the most perfect beam I have even seen, perfectly round perfectly graduated, untill it sharply goes into a laser beam spot. A slightly messier bulb like the 1909 (similar to what you have probably in that the filiment is probably longer, and it probably has a dippy doo of glass from manufacturing on the top) still loses all it's artifacts when centered and focused into spot. There is no artifacts in the spill or the spot at focus, if you open it up there is a shape to the opening spot but it is well smoothed and more donut like, (or small butterfly if not centered or if your bulb has a large glass melt on top). It's a really good reflector, adds a little length and some heft but not much, and the beam is really sweet. I wish that there was an FM 2" with a larger opening and parabola to match a larger bulb like the mid range Osrams for those who want to stay close to stock mag form-factor. I'm thinking of boring one out just a hair to see how it does with a 64623 bulb, I'm afraid I will lose alot of light at the back end as the area near the bulb hole is one of the most important to surround the bulb as much as possible.
If you get one and don't like it, you can sell it, assuming you treat it gently and don't touch or scratch the interior surface.
