3-way dimmer to 2 fixtures

In my home I have a main flr to 2nd flr stairwell with 2 existing ceiling octagon boxes in each of the halls, one each at top and bottom; presently controlled by 2 3-way switches, one on each level. This is working fine. Am I correct in assuming that these 2 lamps are wired in common as a single load?
I am replacing the lower/main level fixture with a LED type, that I would like to put a dimmer on (DIVA-CL). The upper will remain std incandescent.
If I put a DIVA 3-way to replace the lower 3-way wall switch, leaving the existing 3-way upper switch, what lighting performance should or can I expect?
Specifically, will both lamps be dimmed during operation, or will it vary, depending upon which switch (upper or lower) is used to activate the 2 lamp circuit.
I only wish to dim the lower new unit, and leave the previous upper normal. Is this wish possible? Or would I need to put a DIVA in the upper wall switch as well to control the upper light level. Or is that even possible?
If I have to live with them both being dimmed, then I would put up with it.
Any comments/suggestions/solutions would be appreciated.

tks.,

Hello DougDimmer,

Thank you for your post!

Overall, it appears you are looking for one light to dim and one light not to dim.

Unfortunately, none of our dimmers can do this. When a dimmer dims, it physically dims the line voltage through the entire run, there would be no way to prevent this for the top hallway level incandescent. The only one this can be achieved is by re-wiring so one switch controls the LED and another entirely separate switch controls the incandescent. You would still be able to do a 3-way, but then you would have to expand your wallbox.

Hope this helps!

Julia K.