James, here are a couple of shots I did hastily this afternoon. They show the FM34 beam shaper on a G3 with a P90 lamp. The power source is 2 Pila 17500's so it's not running at a full 9v, but that's just as well because I don't think my compact camera could deal with all that light. One shot shows the cover open, the other closed.
You can see that the open shot shows an odd shadow at the top. That's where the flip cover gets in the way of the beam. The cover closed shot shows how the oval hotspot of the P90 beam is smoothed out to give a nice wall of light.
Open cover
Closed cover
(I deliberately let the light fitting get in the shot just for scale.)
My personal feeling is that this type of filter/diffuser adds rather a lot of bulk to a light, particularly a 2 cell 6P or C2. On the other hand, if you are likely to flip the cover open and closed often during use then it's probably worth having. I've never seen an M61LL in action so I don't know how concentrated the spot is, but you can see the FM34 does bring the overall light output striking the target down by a lot. I think this would be quite good for close work and walking.
Somewhere, I have an FM35 red filter, but couldn't find it so no picture. It's a very heavy red tint and cuts the output of a P90 considerably. The spill becomes very dim and you'll end up looking at the spot only. I haven't found it particularly useful so far. Unless you actually need the red, the diffuser will probably be more useful. You could always tape some red acetate or theatre gels to your G2 to see if you will really benefit from a red filter.
Hope this helps.
