Toning POP

[nickc1]

I am going to so some photography with young children this summer (salt

prints, pinhole camers etc) and would like to include some work with printing

out paper. Unfortunately the only toner I have used with this in the past has

been gold - but the budget will not run to this - what experience has anyone

else had with polysulphide or selenium tonong POP??

 

Thanks

 

Nick

[ted_chambers]

Check this article:

 

http://unblinkingeye.com/Articles/POP/pop.html

 

Towards the bottom he talks about toning with selenium after the fix, rather than before, as would normally be the case with gold toning.

[timsumma]

Funny how the guys who write these articles seem to delight in giving us long chain chemical reaction formulation and yet get no where close to certain basics in photography.

�Selenium works fairly well in sufficiently weak solution (too strong causes image bleaching), though in my opinion the colours are inferior to gold. It needs to be used at about one-tenth of normal working strength (which, for Kodak Rapid, means a dilution around 1+39), and gives purplish colours.

Prints must be well washed after fixing, and are immersed in the selenium for anything up to 10 minutes (by which time its action will have gone to completion). They will appear to fade if put in dry, but they do this in water too, and it is simply the �undoing� of the dry-down effect. The initial orange-brown colour starts to look pink-brown after about 2 minutes, after which the colour becomes gradually more neutral. After the full 10 minutes, prints still retain a hint of redness, but this disappears (and the tones darken) on drying.�

So lets correct several points. Kodak Rapid Selenium Toner comes as an industrial concentrate. Kodak has refrained from adding additional alkalis to the chemical make up of the toner concentrate. If you experience �purple� coloring in shadows or in this case over most of the image surface it is due to the shape of the deposit of selenium metal on the surface of the silver forming the image. To alter this effect you change the pH of the toner. Simply done you add a spoon full of 20 Mule Team Borax to your toner. It is not important that it be measured because you are trying to shift the pH as far possible and the compound will do this to the extent it can and then stop.

To protect the reactivity of the selenium toner you are advised to add the specific product Orbit Bath. The volume is to drop in 6OZOrbit Bath to a gallon of working strength toner. When you dilute the selenium, use a lesser portion of water than required for the final dilution, add the Orbit Bath, then top the mix off to get the proper dilution. With the Orbit Bath you should be able to increase the concentration of the toner bath.

As caution, Selenium is vary unstable around ANY acids, the result is a strong and immediate reduction of Selenium in the form of an orange red precipitant. This is nasty and will stain any thing it contacts. Acetic Acid is a great indicator if you get the toner mixed up with other baths, but test it as a sample in a glass graduate and be sure to use paper wipe when removing the deposit off the glass surface after it precipitates.

Last note, Because you are working with children you probably would not do the following but when experimenting you may want to do it for yours. Use any sulfur based toner first, then use heavy metal toners. You can always get a tone from sulfur with silver but because of the silver deposit size it will not be pleasing by itself, (the fixer is actually toning if you will, the image as you do the fixing, fixer is sulfur based). Alternatives to Selenium toner are certain copper based formulas. Copper is a heavy metal toner so would come second. Finally, you can effect a change to the image by using Orbit Bath in the initial fixer, it will modify the effects of the fixer reaction on the silver deposits, though subtle in its effect, in the end this will create an impact to the final toner reaction