Newbie here ... again.
When I get to creating paper negatives using Arista pearl paper, I plan in doing tests at different exposure times. My Pinhole assist app has some presets that I thought would be a good place to start: Arista EDU 100, Arista EDU 200, Arista EDU 400. (t also has a series of ASA settings, e.g. ASA 0.5, 2, 4 .... 100, etc.)
Q. Any suggestions on which of the above would be good exposures to start with?
Q. If I take photos of the 10-step calibration target, below, should I assume that a good paper negative would look something like the second image (which is a 'negative' where the darks and lights have 'swapped' places, so to speak)? I'm mainly concerned with the 10 steps from near black to near white.
Thanks, David
I'm not familiar with that paper, I'd start with something like Iso 6 (HDPP is 2-3).
It wouldn't reproduce exactly like that, but you are correct in your thinking. If you plotted that as a graph "density vs the step number (relative time)", that would plot as a straight line linear increase. What you would expect to end up with is a flattened "s" shaped curve. It's also a great way to check your iso estimate, as the curve will shift to the left or right accordingly. So if steps 1-5 are white, rising to step 10 mid grey then its underexposed (or step 1 mid grey rising to steps 5-10 black, then it's over exposed) for example.
You should also bear in mind, you might not reach black, as a Multigrade/Variable Contrast paper relies on the colour of light to change the grade/contrast, as it contains different emulsions and all emulsions need to be activated to reach maximum black, which realistically is not possible outside of a darkroom.