Hi everybody,
To my surprise the archives seem to have nothing on the subject of speeds of pap er (contact or enlarging), nor do I find anything in my manuals or paper manufac turers' spec sheets. My problem is a simple one: when I've determined the corr ect exposure for a given negative on a specific paper, how can I calculate with precision the correct exposure for another paper or papers. I realize that I co uld run my own tests (and to an extent I've already done so much in a hit-and-mi ss way), but this seems to be an area (as with the much-discussed matter of spee ds of films) where pooling of experience might be of general benefit to many on the forum. My questions:
(1) Nomenclature. Take, for example, Oriental Seagull fb dw glossy G-3: ISO sp eed P400, ISO range R80. To what do "P" and "R" refer? What is the range?
(2) Relative speeds. The same paper as above in the very hard contrast G-4 grad e is ISO speed P200, ISO range R60. How are the G-3 and G-4 numbers related to each other in terms of exposure?
(3) Are paper speeds consistent from paper to paper and from manufacturer to man ufacturer? Are all P200 papers equally sensitive?
(4) Are sharpness or other image qualities, all else being equal, related signif icantly to paper speed? Contrast is not an issue here for the purpose of this qu estion.
Thanks in advance for any replies. Good light, Nick.
Bookmarks