Reciprocity for RA4 papers

I want to respond to jazzpatman's reply -- the reason that knowing the
individual reciprocity curves is important becomes apparent when you go from
a 5*7 print to an 11*14 or 16*20-- you can't simply change "time" to reflect
the change in magnification -- and unless you have unlimited darkroom time
it's helpful to know what you're dealing with. It's one thing for a
minilab's production, it's another if you are making a fine-print for a
customer.

This certainly isn't original to me -- it was discussed in PhotoTechniques
sometime in the mid-1990's -- the author of the article

"Why are you worried about reciprocity? If you are making a test print, you
will
end up adjusting the color to whatever shift occurs when you make the final
print.

In labs, these papers are used at exposure times varying from less than 0.5
seconds on minilab and smaller size automatic printers, to several minutes
when
printing large murals with horizontal enlargers.
Bernie

I want to respond to jazzpatman's reply -- the reason that knowing the
individual reciprocity curves is important becomes apparent when you go from
a 5*7 print to an 11*14 or 16*20-- you can't simply change "time" to reflect
the change in magnification -- and unless you have unlimited darkroom time
it's helpful to know what you're dealing with. It's one thing for a
minilab's production, it's another if you are making a fine-print for a
customer.

This certainly isn't original to me -- it was discussed in PhotoTechniques
sometime in the mid-1990's -- the author of the article

"Why are you worried about reciprocity? If you are making a test print, you
will
end up adjusting the color to whatever shift occurs when you make the final
print.

In labs, these papers are used at exposure times varying from less than 0.5
seconds on minilab and smaller size automatic printers, to several minutes
when
printing large murals with horizontal enlargers.
Bernie