Re-using ID-68

[Stan160]

I have a litre of ID-68, mixed from raw chemicals. Developing time recommendation I found was to use times for Microphen. First couple of rolls of HP5+, developed for 6.5 minutes in stock developer turned out fine.

The Ilford datasheet for Microphen recommends a 10% increase in development time for each subsequent roll of film in one litre of stock, so for the third roll of HP5+ I need 6.5 minutes+10%+10%, which comes to 7 minutes 52 seconds. This roll was exposed by a friend in a variety of lighting conditions. All images are printable, but a lot are biased towards dark negatives - could be over development, could be overexposure. So the next roll was from said friend's Kiev 60, and had been in there for over two years! She thought it was HP5+, and we forgot to check the backing paper, so added another 10% to the developing time to give 8 minutes 39 seconds. The negatives looked fine, well exposed and properly developed, maybe a little dense, but on closer inspection it turned out that the film was FP4+, which has a development time of 8 minutes in Microphen, so should have been noticeably undeveloped because it was the fourth roll through the same litre of stock ID-68. So it seems like the correct development time is not increasing as I reuse the developer stock, or at least not increasing by 10% per developed roll.

Have I misunderstood the Ilford datasheet, about increasing development times when reusing stock Microphen? Otherwise, should ID-68 be treated differently in this respect? Should I just keep using the same times no matter how many times I reuse the developer (of course there will be an upper limit)?

Thanks,
Ian

 

[Ian Grant]

it's a few years since I used this method, I now always use a replenisher with devs like this. But those Ilford suggestions are about right. I always used larger volumes even while still at school which makes it slightly more consistent and easier to monitor. half your problem is you don't have control over the exposure of your friends films so it makes it hard to tell what the problems are.

Ian

 

[Rob Archer]

I used to use Microphen a lot and after a few disasters I only used it 1+1 and discarded it. I found the 10% rule varied depending on the film. I found Tri-X in particular would almost always be underdeveloped if I allowed 10% per film. I haven't used it for a while and am thinking of making up my own ID-68, so any observations here would be welcome to me, too.

Rob

 

[john_s]

Has anyone compared Microphen, ID-68 and Ilford Replenishing Developer? I like to support Ilford, but the discontinuance of Microphen in the larger size makes it more expensive, and inconvenient to make up quantities. I never re-use film developer. So I'm thinking of making up either ID-68 or IRD. IRD would probably have a lower pH than ID-68 (less borax, more boric acid), which might make it more like Microphen (wild guess).

 

[Ian Grant]

John, I have tried all three. The IRD was a commercial developer for processing machines, it's a PQ derivative of ID-11 & the first version of which was published in the British Journal of Photography in 1954. By 1960/61 Ilford were publishing ID-68 as their suggested Fine Grain PQ Developer and like Microphen it was further optimized to give more film speed than ID-11, a separate PQ developer "Autophen" was available for commercial photofinishing lines based on IRD.

In practice the differences between a PQ version of ID-11 & Microphen/ID-68 are slight, but you do get a slightly better increase in film speed with ID-68/Microphen.

Ian

 

[BradS]

I ran a replenished liter of ID-68 for about a year and a half. When replenshed, the stuff gives very consistent results and seems to last practically for ever. Good stuff. I think I'll mix up another batch!

 

[Ian Grant]

I ran a replenished liter of ID-68 for about a year and a half. When replenshed, the stuff gives very consistent results and seems to last practically for ever. Good stuff. I think I'll mix up another batch!

That's really how these developers (including ID-11/D76) were designed to be used. In commercial applications they were never used diluted as one shot developers, ands always replenished.

Ian

 

[Stan160]

OK, I think my ID-68 is working consistently with the Ilford Microphen instructions.

I tried another roll of film, shot my me, in the first litre, with the appropriate development adjustments, and it's turned out pretty good, maybe a little contrasty but this developer has had at least three different types of film through it so not totally surprising.

With a fresh litre of ID-68, and 4 rolls of HP5+, all shot by me on either Nikon FM or FM2N (so consistently metered), and following the +10% time for each subsequent film guideline, all looks fine. Can't tell which order the films were developed from the negative contrast or overall density.

I don't normally shoot more than about 6 rolls of film a month, and I've standardised on HP5+ (sometimes ADOX CHS 50 in the Pentacon 6, but I won't be developing that in ID-68), so I think keeping each litre of stock for a maximum of 1 month or 6 rolls, whichever comes first is going to work as a routine.

Thanks,
Ian