Wednesday, 4 January 2012

PMK Pyro a working solution

I am no stranger to making up developers from powders into stock solutions. The first thing you notice is the very small amount it makes up. Next, it comes in two parts and last, the powder needs to be mixed into distilled/de-ionised water ( used for car battery top ups ).
Solution A mixes up as follows:
Pour 80 mls of de-ionised water at room temperature into a measure. Open the packet marked A inside there are two sachets, take the smaller one and mix that in until it dissolves, do the same with the second one. It is important that they go in, in the right order. Make the solution up to a 1oo mls once done pour into a small storage container.
Solution B
Pour 160 mls of de-ionised water at room temperature into a measure. Add the contents of packet B slowly to the water stirring all the time until dissolved. Then top up to 200 mls. Again pour into small storage container.
Some notes:
By the time all the powders are mixed in, the amount of top up will be very small. The distilled/de-ionised water helps it to stay fresh and will keep well in partly filled bottles. Solution B has a bit of drop out and will need to be shaken clear before use. Makes up to 10 litres of working developer.
Freshly made PMK Pyro
Making up a working solution:

A normal mix is as follows,
   One part A + two parts B to One hundred part of water.
e.g: To make 600 mls of working developer. Measure out 500 mls of water add 6 mls of solution A then add 12 mls of solution B and top off to 600 mls and stir. It is important that they go in in this order.

   When you add part B to the water it will turn a straw colour, if this happens it's OK to use.
   Working temperature should be 20- 21 degrees C depending on which make of film you are using. You can check this with Digital truths massive dev chart.
Used PMK Pyro
developer.You reuse this at the
end of the process to add extra
stain to the negatives.
   Prepare everything else before you make up the working developer then use it straight away as it oxidises very quickly.
   When you pour the developer out at the end of the allotted time the solution will be very dark brown.
   It is a 'use once and throw away' developer.
   It is not necessary to re-dip the film in the developer after it has been fixed to increase staining.
   Make working solution up with filtered tap water.

Test strips before printing.

The test strip is the foundation to obtaining a good final print. Unless you have one of RH designs excellent Analsyser Pro enlarging meters. If not the most common way of producing a test strip is with a sheet of card moved at timed intervals across light-sensitive paper. There are several things you need to set before doing the test: the size of the print, the aperture of the enlarging lens and making sure you have sharp focus.

10 x 8 test strip.
Once all this is done how big should the test print be? This is down to personal choice but you should consider whether the use of whole sheet, half, third or strips give the best test results. If using a test strip of about two inches (50 mm) you need to make sure that each segment includes a full range of tones from the lightest to darkest so you can see at which timed interval gives the best high values and shadow areas. It is much easier to achieve this with the larger test strip.

What should the time separation be? A good starting point for prints around the ten by eight size is five seconds. These intervals will give you a rough idea of what the exposure should be. This can be refined with further test strips of two and/or one second if needed.

On what grade of paper should you make the test print? Grade one is standard practice. If the method you use places your negatives at a particular grade In my case it is grade three then you should do your test print at that grade unless you are using the split grade method.

Related posts:

Evaluating your test strips