Hypo heavier than water?

I've been reading this and getting a good laugh from many of the posts...... Sorry guys.

For one thing, if you use a tank for development, then the first film to see developer is at the bottom as you fill the tank but as you pour it out, then the last film to see developer is at the top. Therefore, contact time balances out.

Yes, pure hypo solution dropped into a tank of water sinks. Then it is diluted, the speed depending on water flow rate, and it is dispersed through the tank and out as fresh water replaces the old. This is described by Mason in his textbook which I have referred to many times regarding washes.

As for things being heavy... Well, Bromide ion and Iodide ion are heavy. Therefore, in some stand development or low agitation situations, you see drag marks as the halides diffuse. And, which way do they diffuse? Down. Gravity wins. But, if you are developing 120 film or 2 rolls of 35mm, you rarely see the top drag marks reach the bottom of a 120 roll much less the second roll of 35mm in your tank. Reason? Same as the hypo above, it is rapidly diluted on the way down. Agitation totally defeats this downward drag.

Of course, the proper degree of stand development gives you edge effects. This is good "drag".

Anyhow, thanks for the posts. Many of them ave lightened my day(s).

Someday, I would like to test one of Dan's prints for wash and fix thoroughness. That might be interesting.

PE

Brighteners?

RalphLambrecht said:

Using this method, are you not washing out the paper brighteners?

Click to expand...

I thought those were reserved for RC papers. Perhaps my eye has
not been trained so as to notice. If I'm loosing brighteners then I'm
in good company. According to a student of his Bruce Barnbaum
also uses overnight soaks. From my readings few use overnight
soaks. From those few readings I don't recall loss of brightener
being an issue.

Total wet time, developer through the last soak, runs about 16
hours. I went 20 plus one time and had emulsion wiping off on
the drying sponge. I've never tested for soak time minimums
though have tested many times using the HT-2 test.
Minimum times I suspect are well within the
single digit range. Dan

dancqu said:

I thought those were reserved for RC papers. Perhaps my eye has
not been trained so as to notice. If I'm loosing brighteners then I'm
in good company. According to a student of his Bruce Barnbaum
also uses overnight soaks. From my readings few use overnight
soaks. From those few readings I don't recall loss of brightener
being an issue.

Total wet time, developer through the last soak, runs about 16
hours. I went 20 plus one time and had emulsion wiping off on
the drying sponge. I've never tested for soak time minimums
though have tested many times using the HT-2 test.
Minimum times I suspect are well within the
single digit range. Dan

Click to expand...

Dan

I see no need for an overnight soak unless you are suffering from severe shortages. Short, two-bath fixing followed by HCA and a 30-minute wash in a vertical print washer reduces residual hypo to recommended levels. Brief sulfide toning gives the image silver further stability without changing image tones significantly. This provides the shortest processing time, attended or unattended, and produces very 'archival' prints. I like to get them done and don't like to continue processing the next day, which in my typical day would be the next evening, at which point we're talking close to 24h wet time.

The water usage for the slot washer can be calculated. Depending on the circumstances some may choose the overnight soak to save some water, but let's not forget that the overnight soak has some inherent dangers too. Prints might stick together, to the walls or partially stick out of the water. Excessive wet times may wash out optical brighteners or other papers additives, and I'm not aware of any research that identifies the influence of extended wet times on paper fiber characteristics.

If it works for you withut any ill effects, fine, but I'm not sure it is the best way. It certainly isn't the quickest way to process a fiber-base print. I'm pretty sure it is the longest.