Text on process lens mirrored

[Fagrid]

I recently bought an Ilex Paragon 15" f/9. I noticed that the text on the front of the lens was mirrored and I'm curious, what is the purpose of this?

 

[AgX]

It is from a special "collectors" edition. It was made to enable the collector to pose with the lens in hand in front of a mirror. Do not overlook that was in times before the invention of the selfie stick.

 

[E. von Hoegh]

Bwahahahaha!!

 

[AgX]

My first thought was that the lens sat in an 90° angled recess and looked at the object via a mirror and that for doing the settings at the lens one would use that mirror too.
But I did not find that convincing.
However, at second thought, it might be intended to facilitate checking under such circumstances what focal length was mounted.

 

[cowanw]

I believe this is precisely correct and such lenses are made for 90 degree mirror usage. At least I have a 10 inch Velostigmat with 90 degree mirror andit reads backwards

 

[AgX]

Maybe someone can come up with a photo of a set-up where such signing really makes sense. I have not seen such yet. Yes, 90° optical path, but with the lens still directly visible.
,

 

[E. von Hoegh]

Maybe someone can come up with a photo of a set-up where such signing really makes sense. I have not seen such yet. Yes, 90° optical path, but with the lens still directly visible.
,

It's a very common setup on process cameras, I have an old 13" Eastman process lens fitted with a reversing prism.

 

[AgX]

But with those I know one still can see the the lens front directly, and looking (in those cases under) the mirror/prism would even more awkward than even taking the prism off. (I know the adjusting issue.) But with those cases where the prism housing covers the lens one could have set the singing on that cover. It seems rather a gadget feature on lens prism assemblies that were not intended to be exchanged. I assume it is only found on american lenses.

 

[MarkS]

The old 'Photostat' process cameras used a direct positive system.The lenses had the prism permanently attached so the (usually) writing would reproduce as readable. Thus the reversed writing on the lens nameplate ring. Those giant cameras were replaced by Xerox machines starting in 1960 or so, I suppose the lenses in question were salvaged from those cameras. I've seen a 21" Kodak Copying Ektanon with the reversed nameplate.