D76 Chemistry question
What is the difference between using D76 "stock" or using A 1:1 mixture ?
Would they be considered equal ?
D76 can be used at full strength with, for example; Some TriX films, Infrared, most sheet films. So it should be stored at full strength and can be stored in smaller quantities at the 1:1 dilution.
Stock developer can be reused and even replenished. The 1:1 dilution is said to provide slightly enhanced sharpness with possibly more noticeable grain.
Originally Posted by Greg Heath
My main reason for using it diluted 1:1, is better shadow detail and tonality with most slow and medium speed films. Try exposing two rolls of 35mm FP4 Plus at box speed (DX coded) and develop one in stock D-76 for 8 minutes at 20*C and the other in D-76 diluted 1:1 for 11 minutes at 20*C and you will see the difference in the shadows.
Kodak recommend that the diluted developer is used with in 24 hours of mixing and it should be used once only and then discarded.
Last edited by Keith Tapscott.; 07-10-2009 at 10:12 AM. Click to view previous post history.
As a novice with respect to developing b&w I've done a little bit of reading here on Apug and other places on-line. My understanding, and I may be way off-base here, is the 1:1 dilution allows for longer development times without greatly increasing contrast or grain and, I believe, is a way of expanding tonal range. But I set up a wet darkroom for the first time just last week so I would defer to those with more experience in this area.
More descriptive question..
This all started when I downloaded:
Arista EDU Ultra 400 D-76 1+1 400 10 min 20C
Arista EDU Ultra 400 D-76 stock 400 7-8 min 20C
(7-8 min listed for 35mm) Will/why would this make a difference, if I am developing 120.
I have been using Kodak D76 Whole Bag mixed with 1 gallon of water
(4 liters or so) and a development time between 7 & 8 minutes for 120 and 4x5 sheet film.
So I was wondering what the difference was between the two mixtures.
I'm, assuming "stock" is the whole bag + filling the gallon (4 liters about)
Physically...What would a one-to-one mixture be? Pretend you are mixing it for me, tell me how you would do it.
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1+1 or 1:1 means one part stock d-76 mixed with one part water. For example 250 ml stock d-76 and 250 ml water
Isn't it the US gallon? About 3,8l IIRC.
Originally Posted by dances_w_clouds
1 U.S. Gallon =3.785 liters
1 Imperial Gallon = 4.546 liters
and more info down the rabbit hole:
Yes: you were all right I wasn't. I noticed my mistake after my morning coffee and cig. I was doing my measurements to Imperial gallons which is ALMOST 5 liters.