(modern) 240mm Sironar N vs. (older) Schneider 5.6/240mm aka 12/420mm

[Bob Salomon]

The general rule of thumb is that using separate cells of a convertible lens will lead to a bit less performance than using than using both cells together, but the big advantage is having more focal lengths. A perfect lens is nice, but a mild bit of Schneideritus shouldn't be a big deal, but you should certainly pay less for one that has it.

A bit less? A lot less! Plus a lot more required bellows! Plus aberrations!

[Peter De Smidt]

Bob's right, as usual, but how important those things are very much depend on the situation and the photographer.

[Jbuck]

at the end is always a bit better to spend a bit more money and to get something a bit better, than to find a cheap solution that cr*ps out and than i can only complain

[MAubrey]

And did the shot have fine detail on the edges? Did you use movements on both?

Yes, sir.

~3" of front rise, but the shot was horizontal and ~1:4 magnification, so I'll be the first to admit that I wasn't pushing limits of the image circle on either lens.

It was a good (=helpful for me) test for the kinds of subjects that I'm interested in shooting, but nothing more than that, especially since I'm not doing any enlargements. I'm not going to claim anything more than that.