Re: Processing 4x5 sheet film

Peter Marshall (petermarshall@cix.compulink.co.uk)
Mon, 29 Jul 96 18:01 BST-1

In-Reply-To: <v01540b00ae218e3d6fbd@194.19.6.43>

Per

I think the problem you are getting with cyanotypes is probably not related
to your negatives or their processing, but to the paper you are using.

The negatives I have used successfully for cyanotypes have a longer tonal
range than those I normally use for silver printing - you would need to
increase the time in the CPE2 by perhaps 20% over the normal time for silver
gelatine. They would probably print ok on a grade 1 paper. I have not used
low contrast negatives.

For all the alternative processes I would recommend the use of developers
that give low base fog. Often those sold as 'Universal' developers are more
suitable than normal film developers - I would recommend Ilford PQ Universal
as an example. This can be diluted 1+20 or 1+30 to give controllable dev
times (probably in the range 3 - 7 minutes).

One paper I have found works reliably and well is Fabriano Artistico. It
needs no preparation before coating. You can use the Keepers of Light
formula or you can double the concentrations given there.

You need to expose fully - until the highlight detail is fully present and
the shadows have a metallic sheen. A typical exposure in sunlight is
probably 20-30 minutes for a cyanotype.

Hope something in this helps,

Peter Marshall

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