RC vs Fiber ISO?

[Fragomeni]

I’m getting back into working with paper for negs and just curious if folks have found that on average RC and Fiber sit around the same ISO rating or if RC is a bit faster. I’ve heard this but haven’t confirmed with anyone. Thoughts?

 

[removed account4]

Hi Francesco -
I am out of the loop, all my paper is old but it depends on if it is MG or Graded too, AND the quality of the light
most photo papers are blue sensitive so FB or RC can be as sensitive as ISO 24 one day and 6 the next.
I used to use Agfa grade 1 and 0 to shoot studio type portraits with a tungsten and neodymium light sources.
they were SOOO SLOOOOOW, I'm talking 30-45 second exposures!
Good luck with your tests and have fun with that giant beast of a camera
John

 

[Michel Hardy-Vallée]

Based on spec sheets, both RC and FB can achieve comparable ISO (P and R) values in a lab context.

In practice, I found that these ratings are sufficiently reliable when switching papers for enlarging the same negative, so I would suspect that an in-camera context would work likewise.