Re: Vandyke Brown Contrast Control - Question for Liam and Sandy

The background really comes together at several points. Some of my
early tests with VDB clearly proved that a couple of methods
described in the literature for contrast control with VDB are
virtually useless for this purpose. The two methods are, 1) mixing in
a small amount of dichromate with the sensitizing solution, and 2)
adding some dichromate to the water developer.

So I posted a question to the list as to how this might be achieved
and Liam Lawless replied with an idea he thought would work and
offered to send me some of his supply of ferric citrate. When I
received the ferric citrate from Liam I mixed it to form what I then
called an alternate VDB solution, which I tested in various ratios
with the classic VDB formula and developed a guideline of rations or
proportions by which the two solutions could be combined to cover a
fairly wide range of negative DRs. What you see in PF-8 is my chart
for the ratios.

The original ferric citrate that Liam sent me went into solution
slowly, but as Carmen Lizardo reported, ultimately it dissolved on
its own. However, I soon ran out of the cache that Liam sent me and
ordered 100g of ferric citrate, labeled granular purified, from
Tri-ESS SCIENCES, INC. It was extremely difficult to get the new
stuff to go into solution, and in order to do so I eventually had to
mix it with citric acid and sodium citrate, which as I understand it
forms some kind of new light sensitive citrate. Most people who
ordered ferric citrate from Tri-ESS SCIENCES, INC experienced the
same kind of difficulty in getting the ferric citrate to go into
solution.

I eventually quite working VDB because I found that traditional
kallitype with ferric oxalate offered more contrast controls with,
IMO, a richer and more elegant final image.

Sandy

>In Post-Factory #8 two formulas were given for variations on part A
>of the VDB classic formula. Liam Lawless created one formula and
>Sandy King the other. Different ratios of the classic and the new
>part A were added to the standard parts B and C resulting increased
>contrast over the standard VDB print. I intend to try each.
>
>Both of the new formulas used Ferric Citrate. I just ordered some
>from the source listed,Tri-Ess - by the way, Tri-Ess is going out of
>business and is now selling off its remaining stock.
>
>Carmen Lizardo, the author of the article describing Liam's formula,
>apparently had very little trouble getting the Ferric Citrate to go
>into solution. She said that eventually it all did. For Sandy,
>however, it sounded harder than steaming diamonds until tender.
>
>Liam, what was your experience? Was there anything the article left out?
>
>Sandy, did the sediment ever clear for you?
>
>Dan Williams
>Enumclaw WA
>dtwilliams3@comcast.net
Received on Tue Mar 15 20:43:54 2005