[vyoufinder]

Sorry, there nothing to see... except reality
Some aerial lenses used during WWII have the highest level of thorium in their glasses.
Single and cemented elements yellow the same way.
Btw, at the time of the yellowed Takumars, very few lens makers used Canada balsam (one notable exception was Boyer).

Btw No.2, some lanthanum glasses can yellow as well, because lanthanum coming from a certain source (Chile, IIRC) contained thorium impurities.

Cheers

Paolo

I was not referring to yellowing. I could add that with Photoshop if I wanted to I suppose...

However, if you do not see how different glass recipes affect the end result, that's fine. When compared to other glasses which have a high refraction index, it's unlikely to see a discernable difference. A high lead glass has a different "look" than does a highly thoriated one, has a different look than does a quartz lens, has a different look than a plastic lens. I am not alone in noticing this. It's not like I point out the differences definitively, I will admit, but to think there's absolutely no resulting characteristics from the difference in materials used seems to deny physical principles.