Are Z lenses APO lenses?

PLShutterbug wrote:

as1mov wrote:

are the Z lenses APO lenses in Leica's sense?

A lot of Nikkors use exotic glass, particularly low-dispersion elements, so according to Slack’s definition, most Nikkor Z lenses are APOs.

Frankly, this sounds like just a marketing buzzword/acronym. Kind of like Nikon marking certain Z mount lenses as “S.”

Nikon’s “S” line Z-mount lenses are very well corrected, particularly when their software corrections are applied.

Indeed.

Nikon and Canon have never designated regular photographic lenses as APO ever.

Just putting the term APO doesn't make the lenses better corrected for chromatic aberration.

Leica puts the APO designation on several f2 and slower lenses these days; there are no comparable lenses in the Nikon lineup so one can't compare specific performance. Traditionally, Nikon used ED designation on super telephotos, if you compare the optical specification of these lenses with equivalent Leica "APO" lenses, you will notice that both use ED glasses of similar type.

For example:

Leica 280mm f2.8 APO - https://patents.google.com/patent/US5388006A/en

This design is from 1991.

From the same era

Nikkor 300mm f2.8 AF-I

https://patents.google.com/patent/US5253112A/en

To compare the color correction of specific lenses, you would need equivalent lenses in the two brands.

If you looked at the optical specs of Z lenses (https://cameragossip.github.io/nikon-lens-patents.html) - you will find many use ED and fluorite glasses. But Nikon doesn't put the APO designation on any of them.