I've noticed that my new LED Mag Lights don't focus the way the old ones did. With the incan lights you could have a tight beam or a flood. With the LED you can have sort of tight and sort of flood.
I've come to realize that most of what I use mine for I don't really need a tight beam, so I put diffuser lenses in both of them (a 3D and a 2AA). I like them a lot better that way.
The mag with a light bulb differs from the one with an LED because they emit light differently.
See with a light bulb the entire globe is used to cast the beam, not just the tip of it. So the bulb sticks out of the reflector tunnel which utilzes light from the front to the rear of the bulb. Light from the rear of the bulb beams backwards and the reflector bounces it forward. The tunnel is longer to allow the bulb to go from total light emitter (flood) to a just out the front emitter (spot). I'll explain more...
An LED is largley on a flat surface and mostly puts out light forwards. The tunnel is very short. The relationship of light hitting the reflector is vastly different. It becomes a lot more 'tricky' to make a relationship between the front firing LED adjustable and end up with a good spot or good flood. It's why sliders are popular and even those are less than perfection of the fixed beam lights.
The incan reflector has a cam lobe to create the long tunnel. It is angled at the tip to change relationship to the light bulb assembly. When you twist the head the angle causes the light bulb to either get "sucked into" the tunnel thereby placing a collar around the bulb to either reduce or increase light that hits the reflector. When the bulb is sucked it less hits the reflector so spill is reduced. The further it goes in the less light from the bulbs globe is visible until it becomes an only out front emitter which is the spot. Keep rotating and the bulb begins to go back in. Keep going further it goes back out.
The LED does not have the cam. Twisting the head the reflector moves forward or backward at the same angle as the pitch of the threads. And since the tip against the switch assembly is flat once the LED has been sucked in the shallow tunnel it stays there moving continually farther into the tunnel as you untwist the head.
Now Mag has chosen differing twist ratios in certain lights. The 2aaa mini mag for example has a fairly flat thread pitch. What I mean by that is given one or the other the rotation of one full turn of the head moves the head farther forward on steep pitched lights like the XL50 vs barely moves it forward on the flat pitched ones like the 2aaa minimag.
An incan Solitaire for example, a whole rotation of the head finally gets you the spot you seek. It does not use an angled cam so following the threads to suck in the bulb is required so it takes a few twists. The XL 50 LED has a steep pitched thread so a quarter turn goes from spot to spill.
Realizing that sounds complicated...
A cam'd on the right. Non cam'd on the left.
An incan mini mag has a cam. An LED does not.
The LED mini mag has a fairly flat tread pitch so it takes more twisting to pull the LED into the tunnel vs the steep pitched XL 50.
Hope that makes sense.