You don't appear to have described the film you use , but Ilford for example,don't recommend surfactants,or pre-soaks for their films, at least in the pre,or development, phase.
You don't appear to have described the film you use , but Ilford for example,don't recommend surfactants,or pre-soaks for their films, at least in the pre,or development, phase.
Ken, I use a surfactant (Triton X 100) in both solution A and B Diafine with slow but continuous agitation in a small tube. The viscosity of the developer doesn't change with the addition of 2 to 4 drops per 8 oz. so I suppose one could say the water is not wetter. The idea is to reduce the surface tension at the film surface which will then enhance the penetration of the developer solution at T = 0. This really only ensures that the rate of take up of developer is linear over the time of development.
This is a common industrial technique especially where very uniform wetting of process liquids are needed on hydrophobic surfaces such as with many plastics and especially with anodic oxidation processes such as with anodized pigmented aluminum where one needs uniformity of pigmentation.
Absolutely vital technique in some integrated chip fabrication steps where incredibly uniform wetting of wafer surface is required.
The notion is that it should aid the uniformity of development, but I will say to establish this in the context of Diafine would take more precise tests than I have done. I use the surfactant rather blindly as insurance of uniformity.
Nate Potter, Austin TX.
Sorry, this has been Kodak 400 TMAX.Originally Posted by Ian Gordon Bilson
Ken,
First, I would not call the shuffle method of agitation you use "continuos" agitation. If you are shuffling through 6-12 sheets of film at some point most of the sheets are in contact base/emulsion. This could easily cause some type of uneven absorption of the developing agent, especially with short time in Solution A. I am not going to say you can not get even development with two-bath developers and shuffle development, but this method complicates matters a lot IMO, whether with traditional development or with two-bath formulas.
On other matters.
1. A pre-soak with pure water should not cause uneven development if the remaining steps are carried out appropriately. The pre-soak results in some swelling of the gelatin emulsion and will therefore affect the rate of absorption of the developing agent by the silver halides, which are embedded in the gelatin. Depending on the film, the rate of absorption could be faster or slower. For this reason I generally favor a fairly long development time in Solution A (with warm solution), which will ensure that the emulsions absorbs as much of the reducer as possible. However, with a developer that is re-used the pre-soak should be avoided because it will result in a slow, but inevitable, dilution of Solution A.
2. Regardless of the instructions that come with Diafine I have seen no evidence that continuous agitation, if gentle and random, causes uneven development. To the contrary, my experience is that a fairly long development time at about 75º F, say 5-7 minutes, with continuous agitation, is the best form of agitation for Diafine and other two-bath developers.
3. The use of a surfactant makes a lot of sense in theory for the reasons mentioned by Nate. And I have seen no evidence that the use of a few drops of Photo-Flo will negatively impact the chemistry of the reducer in Solution A with Diafine.
4. After removing the film from Solution A drain it for 10-15 seconds, and then immediately introduce it into Solution B. If the surface tension has been broken by the surfactant this should asure that the film is wetted out uniformly by the alkaline Solution B.
Sandy
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There are always trade offs, for every alternative methodology, and for what you gain by two bath development, the trade off is the risk of uneven development, and a more complicated process. This is especially true for staining developers. None of the benefits of two bath development are compelling enough for me to switch from single bath development, but to each, his own.
Jay,
I agree that there are trade offs with two bath development.
For me the compelling benefit of two-bath development is the ability to limit highlight development in scenes of very high contrast. There are of course other ways to handle scenes of this type, but in my experience none are as fool proof as divided development.
And if one's work flow is built around scanning and printing digitally, or with some wet process via digital negatives, the slight risk of uneven development is to me a small price to pay, since small negative defects like this can normally be corrected easily in PS.
But in the end, what we photograph, the equipment we use, and what we do with the image, is a highly personal and subjective issue, and there are no rights and wrongs, only alterative paths. Of course, any time our paths fork from the norm there is some risk. In fact, if you were a pessimist that path would always been seen as the one that leads to destruction, as in El jardín de senderos que se bifurcan (The Garden of Forking Paths) of the great writer from the Argentines, Jorge Luis Borges.
Sandy
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Sandy, I agree. And for a true pessimist, all paths lead to destruction.
I'm just learning PS, and I would hate to have to even out uneven development in PS, but that's just me. I don't often spend much time on problem negatives, and move on to better ones, but I'm trying to improve my skills and make more negatives viable. For me, a single bath developer of suitable composition, with generous agitation, gives me the most consistently reliable results. I've had my fun with two bath development, and I don't begrudge anyone else the pleasure. My caveats are meant for those tempted to see two bath development as a panacea.
Here's a test with a few drops of Photo Flo added to Solution A. There is no uneven development as far as I can tell, and no ill effects from the wetting agent.
I just love these test shots. Here is a building with a dark brown door in deep shade, next to some snow in full sunshine, along with blue sky with white clouds. I placed the dark brown doors on Zone IV and let the rest just go. Much of the scene should have been white, but even the snow is printable and the car looks normal, instead of the Zone VII where it would have ended up with normal development.
As usual, I had to add contrast and lower the shadow values a bit to give some snap to the image. With regular film I'd have to use a polarizer and/or yellow filter to get even a hope of detail in the sky, but here, no filter was used. If this was a movie production, big reflectors or lights would have been used to balance the extremes.
Your sunny day has been transformed into a depressingly dull, overcast one. Victory?
This was a test shot. With the same exposure and ordinary development, it would have looked more like the image below: even less of a victory perhaps.
In non-test situations, the accommodation of high contrast can sometimes give pleasing results. Here's a shot made under a similar brightness range. Not the greatest photo of course, but I like it. The fact that it was developed in the same batch of developer, is also gratifying.
Spectacles, 2012
Sinar P, 210mm Macro Sironar
4x5 TMY, Diafine
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