Raid,
Since you have both 50mm Heliars (f/2 and f/3.5), perhaps you can answer a question that I've had on my mind. Are the two lenses the same?
That is, if you set the f/2 version to f/3.5 and match apertures from then on, do you get the same result?
I had the collapsible f/3.5 version, but I sold it as it is rather fiddly. Now I have the LTM f/2 version, which I love. From f/2 to f/2.8 you have aperture adjustable "glow". The old LTM Nikkor 50mm f/1.4 and f/2 had a similar behavior. Anyhow, as the f/3.5 has now appeared in a rigid conical "Mountain Elmar" type mount, I am curious.