Divided developement

[phfitz]

Can anyone give me the equivilent measure of sodium carbonate to match 5g/lt of borax for the B solution?

X-ray film is cheap and easy for 8x10 and larger BUT it has emulsion on both sides making developement a bother.

Processing in a tubes leaves the back mottled, folding it into a taco in a window screen tube leaves impressions and tray processing carefully with a sheet of glass in the tray is one _ sheet _ at _ a _ time. This leaves dip & dunk with hangers and tanks, lots of chems = divided developement.

Thank you.

 

[Gerald C Koch]

Why do you want to replace the borax in solution B? To reduce the amount of carbonate to yeild the same pH as that produced by borax would effect the action of solution B.

 

[phfitz]

"Why do you want to replace the borax in solution B?"

because I want to see IF it changes the grain sharpness. If so I would use borax for portraits and carbonate for general use.

I want to try divided D-76 with carbonate and divided Ansco 130 with borax just to see the difference. A good start point would save time and film.

 

[holmburgers]

just FYI, mammography film is only one sided.

 

[Alan Johnson]

The pH of 5g/L Borax decahydrate is 9.23 at 20C.
You can make a buffer of this pH from sodium carbonate and sodium bicarbonate solutions:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1258214/pdf/biochemj00962-0041.pdf
To make 0.1M carbonate dissolve 10.6g/L anhydrous sodium carbonate.
To make 0.1M bicarbonate dissolve 8.4g/L sodium bicarbonate.
Mix in the proportions in the table given in the link to get your desired pH of 9.23.
Any other addition eg sulfite may change the pH.

 

[phfitz]

Alan,

Thank you, that will work.

 

[cliveh]

D76 with carbonate

"Why do you want to replace the borax in solution B?"

because I want to see IF it changes the grain sharpness. If so I would use borax for portraits and carbonate for general use.

I want to try divided D-76 with carbonate and divided Ansco 130 with borax just to see the difference. A good start point would save time and film.

Why would you want to change the formulation of D76, which is one of the greatest developers of all time and one that produces perfect negatives for some of the best photographers worldwide?

 

[Gerald C Koch]

Using a carbonate/bicarbonate bath B with the same pH is not going to produce results that are different from what borax will produce.

 

[phfitz]

"Why would you want to change the formulation of D76, which is one of the greatest developers of all time and one that produces perfect negatives for some of the best photographers worldwide? "

Just to do it. (something about belly buttons.)

"Using a carbonate/bicarbonate bath B with the same pH is not going to produce results that are different from what borax will produce. "

That is exactly what is to be seen. I'll find out this weekend.

D-76 uses 100g of sulfite and borax/kodalk and is fine grained but loses some grain sharpness to the sulfite.
D61-a uses 90g sulfite and carbonate, is known for it's 'snap and sizzle' and does not lose any grain sharpness to the sulfite.
What-if D-76 is not losing sharpness to sulfite but to borax/kodalk?
What-if the 'snap and sizzle' can be held to the midtones by divided developement raising the toe and holding the shoulder?

 

[analog what is that?]

I'm about to strat using a homebrew based on phenidone/ascorbate.

Perfect Lazy Old Mans Developer..........

 

[Gerald C Koch]

The optimum concentration of sodium sulfite for fine grain is approximately 70 g/l. Anything more than that actually reduces the effectiveness of the sulfite. This is why Xtol uses 75 g/l.