Developer question

[kev curry]

1ltr of stock ID11 has the capacity to develop 40 sheets of 4x5 according to Ilford.
If my math is correct that means 150ml of stock = 6 sheets and probably 5 sheets to be safe right? The question is will 150ml of stock at 1+1 still have the same capacity as the straight stock? I realize that I've probably entered into silly street here!
Regards kev

[Mark Sampson]

Well, if the total amount of developing agents (in the working batch of developer)remains the same, the processing capacity should be the same. But I've never tested the idea. However, the cost of any developer is almost nothing, compared to the value of your (latent) photographs and the time and effort spent to make them. So don't skimp!

[Michael Gudzinowicz]

No... If you dilute the developer, the capacity is reduced by the dilution factor for the same volume of developer. In other words, the capacity of one liter of ID11 is 40 sheets, while one liter of ID11 (1:1) is 20 sheets.

However, there are problems with that approach. With undiluted developers, one usually takes a volume which is more than adequate for development (75ml/sheet; 300ml/roll), develops the film, and returns the used developer to the stock bottle. Times are extended to compensate for the loss of activity.

Consider one "film" to be four sheets of 4x5 in the following table of extended times (click to enlarge):

7220
Taken from: ID-11.pdf (www.silverprint.co.uk/PDF/ID-11.pdf)

You can interpolate what happens between sheets 20 and 40 (films 5 to 10) by adding 10% to the previous value. Note that the table is for undiluted developers.

Although Ilford gives capacities for a 1:1 dilution of ID11 (below), I wouldn't reuse it in the same manner. The 1:1 dilution does not resist oxidation to the same degree as the undiluted developer, and should not be reused (one shot - toss the used portion out).

ID11, D76 (commercial buffered formula) and Agfa/Ansco 17 developers are similar, and can be replenished. They have a very long life when that is done properly and if they are stored in glass containers. If you want to extend the capacity of that class of developers I suggest that approach. To extend fixer capacity, use the two bath approach.

I've attached a table listing the capacities of Ilford developers (click to enlarge):

7219

[Scott Kathe]

Kev,


1ltr of stock ID11 has the capacity to develop 40 sheets of 4x5 according to Ilford.

Are you sure about that? I've looked at the ID11 fact sheet and can't find that information, in fact I can't find the information on sheet film? (http://www.silverprint.co.uk/PDF/ID-11.pdf).

The fact sheet for Kodak D76 (http://www.kodak.com/global/en/professional/support/techPubs/j78/j78.jhtml), which is supposed to be nearly the same as ID11, says that you can do 4-8x10 sheets/liter undiluted which works out to only 16-4x5 sheets/liter undiluted. This fact sheet also goes on to say that you can develop 2-8x10 sheets/liter of a 1:1 dilution or 8-4x5 sheets/liter of a 1:1 dilution.

Am I doing something wrong here?

Scott

[Marko]

1ltr of stock ID11 has the capacity to develop 40 sheets of 4x5 according to Ilford.
If my math is correct that means 150ml of stock = 6 sheets and probably 5 sheets to be safe right?

Not quite. One liter = 1000ml, therefore 6 sheets per liter is about right, with 100ml to spare, but 40 sheets is definitely not right. Are you sure that's Ilford's figure?

[kev curry]

Right so, 150ml of stock solution = 300ml of solution @ 1+1. They both have the same developing capacity!

The ID11 box states: 1 litre STOCK= 10x135-36 / 10x120 / 40x10.2x12.7 ie4x5.

My darkroom session this morning included 5 negs all @ N+1. So my thinking was how much developer would I require? My film tests were done with ID11 @ 1+1 and each test sheet was processed in 300mls of solution then discarded. I always use my developer as a one shot and never until today developed more than 3 negs in 300ml of 1+1 developer. After a little math I decided that 5 negs would be done 'safely' altogether in the 300ml without doing any adjustment on my usual N+1 time of 12.5min..... the negs 'look' fine but I've yet to print them up to see for sure........Would you folks have done the same?
Many thanks to all
regards kev

[Marko]

Right so, 150ml of stock solution = 300ml of solution @ 1+1. They both have the same developing capacity!

The ID11 box states: 1 litre STOCK= 10x135-36 / 10x120 / 40x10.2x12.7 ie4x5.

Something's still not right here - 1 roll of 35mm or 120 film has the same emulsion surface as 4 4x5 sheets, so it appears that 10 rolls does equal 10 sheets of 4x5.

But what doesn't sound right is the quantity. ID-11 is (almost) the same as D76. My D76 chart rates the capacity of 1 US GALLON at 16 rolls or 64 sheets of 4x5.

1 US Galon = 3.85 litres = 3850ml

3850 / 64 = 60ml of stock solution per 1 (one) 4x5 sheet.

64 / 3.85 = 16.6, so let's say 16 sheets of 4x5 per liter.

Granted, the two developers are not exactly the same and there is likely to be a difference in capacity, but it should not be all that much.

[Marko]

Just as an aside, I use 150ml of D76 1:1 per sheet and disard after use. That's 75ml of stock, a bit more than the 60ml that the math indicates, just about enough to be on the safe side.

If you develop one sheet in 300 ml of ID-11 1:1, I think you should be fine. I'd rather use more developer than less, it's much cheaper than ruined negative.

[Scott Kathe]

I asked this same question a little over two years ago, see
http://www.largeformatphotography.info/forum/showthread.php?t=14460&highlight=d76+capacity

People who uses the BTSZ tubes are using 1 ounce of developer per sheet which is about 1/2 the recommended amount. I'm guessing that the amount Ilford and Kodak say to use would be the amount needed to develop a negative of white rabbit in a snowstorm. In other words a completely white subject, exposed to print as a completely white subject, might require twice the amount of developer as a typical medium gray subject. So for typical subjects maybe one can get away with half the amount of developer and it's the high key subjects that need the extra developer. Please don't shoot me down, I'm just guessing here but I'd like to know if anyone else has some thoughts on this.

Scott

[Michael Graves]

I like HC110 at 1:64 as a developer for high-contrast subjects. According to Kodak, you need 3ml of concentrate per 8x10 sheet. In my Jobo, I typically mix up 640 ml of solution to develop 5 sheets of 8x10. Essentially, I'm using 10ml where I should be using 15. So far, I have had good results on this type of negative. However, as another poster pointed out, if you're reducing significantly more halide that my low-contrast scenes that I favor for HC110, you will probably get different results.

[kev curry]

Thanks to all.
The negs were all fine and printed well.
Those BTZS tubes look worth while.