View Full Version : Developer replenishment for double-sided xray film

16-Nov-2009, 10:10
Reposted here from APUG. Maybe more xray film users here.

I use replenished developer, and I'm supposed to add 23mL of replenisher for every 80sq inches of film developed.

Xray film has emulsion on both sides of the film, so at first I thought I should replenish 46mL for every 8x10 sheet. However, because of the dual emulsion, it develops to usable contrast very fast. So maybe since I'm developing to a contrast index similar to normal film, what I really have is 2 sides, each half-developed, and therefore I should replenish normally.

I'm not sure what process it is exactly that leads to the need for replenishment. I assume the only parameter that matters is how much silver is reduced. So since I'm developing to the same contrast, should I replenish normally or double?

It's my theory that when developed to a printable contrast, the amount of silver reduced by the developer should be the same with single-or double-sided film...the same amount of metallic silver, just spread between the two sides of the film. I figure fixer life is cut in half, though.