When is developer depleted?greenspun.com : LUSENET : Large format photography : One Thread
I have just started using LPD paper developer and am very pleased. A slightly warm tone and I think brighter whites than I was getting with Ilford MG. I know this developer is supposed to last much longer at working strength than most. I use it for a few hours each night and then return it to a container. How will I know when it is depleted? I know I can run a time test to full black but wonder if that is the best. Will there be any other noticable changes in the print that I should watch for?
-- Dave Schneider (firstname.lastname@example.org), August 03, 2001
We use this developer at the community college here. It's changed frequently, so I don't typically notice a problem, but there was one time when it was definately being exhausted and the prints took much longer to develop.
Adams talks about adjusting developing time for weakening developers in The Print.
-- Dave Willis (email@example.com), August 03, 2001.
it will probably change color like get darker or your prints will be extremly flat. very unusual to re use developer. i wouldnt recommend it.-J
-- Josh (firstname.lastname@example.org), August 04, 2001.
Hey Dave, I don't know if Ethol still offers them (I guess you could try Brandess-Kalt now), but they have a nice little spec sheet that details the replenishment schedule for LPD. I've been doing this for years, and use it in both trays, and my tabletop processor as a replenished developer. The instructions are based off the powder form, but for the liquid, they have a similar system. What I do is to mix up a gallon of stock (from the can). I take 64 oz and dilute this 1:1. This becomes my working developer. I then save the remaining 64 oz in a tank with a floating lid & spigot. (I actually mix up several gallons at a time). This tank becomes my replenisher. When I tray process, I keep the working LPD in a jug. I keep a rough count of how many 8x10's (or an equivalent) I run through it, and replenish at roughly 15 oz. for every 45 8x10s. The spec sheet says that a DW 8x10 uses approx. 1/2 oz of developer....I usually print RC, so I eyeball the repl. rates...it's not as critical as film repl. (which i also do in deeptanks)
You can repl. with a 1:1,1:2, or 1:4 soln. for softer prints, or straight stock for harder. Since LPD is phenidone based, it does all this nicely, unlike Dektol which dies very fast. The working developer will turn a color similar to used Dektol, but it's still fine. I dump my processor LPD weekly, but have used the tray developer for up to 3 mos. at a time. The prints are clean, with good d-max, that's the beauty of a repl. system, you can adjust & tweak it as you go along. At the end of a session, juts pour it back into the jug...there are 2 ways to repl., either take out the amount you need to add, or just top off with that amount. It depends on how much carryover you have.
I dump the working tray LPD when I've added approx 64oz of the repl. to it. Then I start over again. It's really the same procedure as film developer replenishment. Let me know if you need more info, I've been doing it this way for over 5 yrs...
-- DK Thompson (email@example.com), August 04, 2001.
As I recall, the bottle of LPD I have says not to worry if it darkens. I don't have it around, so I can't be sure, though.
I've used it after it had darkened and it worked just fine.
-- Dave Willis (firstname.lastname@example.org), August 04, 2001.
Yeah, that's true. The concentrate has a clearer color to it than the powdered form as well. Depending on the batch of chemistry, the stock soln. will have a variety of tones, from a weak brown/iced tea color, to different shades of brown/tan as well. If you don't want to go the replenishment route, LPD still lasts a long time in a tray. You could do your own system, where you might give it a boost every 10 prints or so with a little straight stock, or a dilution as well. You can use it at a 1:2 dilution in a half gallon tray and literally get 50 or so 8x10s out of it in a session before having to replenish...it may turn a color that looks like it's shot, but that's just the way it works...if i recall, LPD stands for: Lasting Paper Developer....
-- DK Thompson (email@example.com), August 05, 2001.