New developer for PFG-03m

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Martin

New developer for PFG-03m

Post by Martin »

Yes or different developing agents. I understand hydroquinone is not particularly active at low pH...
Sergio

New developer for PFG-03m

Post by Sergio »

Yes, would be very interesting, due the actual kinetics attained with balanced developer (finely tunned in my opnion) "buffer" the developer with desired crescent pH values and compare the developed image, since we are interested not in optical densities but fine detail develped image?
Sergey Vorobyov

New developer for PFG-03m

Post by Sergey Vorobyov »

Yesterday I made new developer OD-1 with add of soda (sodium carbonate), 10 g/l for increase of pH.
Nightmare! The photoplate had darkened after 30 seconds! And very slight image! So, hydroquinone had active action and transfer development from physical to chemical action. The black color of emulsion layer is effect from the fine filament balls of metal silver inside of emulsion after chemical development (this balls are absorb the light very big). But we need to fine grains of metal silver as consequent of PHYSICAL develop (and nice light-brown color of emulsion layer). The simultaneous development of test holograms in "standard" developer OD-1 gives good, bright holograms.
So, big pH doesn't useful for this developer. I want make finer selected of proportion of borax and thiosulphate at near future.
Martin

New developer for PFG-03m

Post by Martin »

"Yesterday I made new developer OD-1 with add of soda (sodium carbonate), 10 g/l for increase of pH.
Nightmare! The photoplate had darkened after 30 seconds! And very slight image! So, hydroquinone had active action and transfer development from physical to chemical action."Have you tried to increase the amount of thiosulfate to slow down the developer's action?In Glafkides' book there is a formula for the making of a special developer (for "internal image"):metol...................1.5g
anh. sodium sulfite......50g
hydroquinone..............6g
anhy. sodium carbonate...32g
potassium bromide.........2g
cr.sodium thiosulfate....10g
water.....................1L
And of course you still have the option of replacing hydroquinone by ascorbic acid. Note that ascorbic acid up to pH 9 or so has a slight physical development effect.
Sergey Vorobyov

New developer for PFG-03m

Post by Sergey Vorobyov »

Yes, I know about useful properties of ascorbic acid for holographic developer and this chemical very interesting for me (I made many experiments with ascorbic acid more before). But need long search for optimal use this chemical in developer. I decide single and important question now – create SIMPLE holographic developer from STANDARD photographic developer.
I don't understand the words " "internal image" in your message. And the "Glafkides' book" – it is book for holographic process?
Martin

New developer for PFG-03m

Post by Martin »

"Yes, I know about useful properties of ascorbic acid for holographic developer and this chemical very interesting for me (I made many experiments with ascorbic acid more before). But need long search for optimal use this chemical in developer. I decide single and important question now – create SIMPLE holographic developer from STANDARD photographic developer."I see. In that case you might have a look into Kodak's products. There is an ascorbic acid based developer called "XTOL" which was introduced to replace D-76."I don't understand the words " "internal image" in your message. And the "Glafkides' book" – it is book for holographic process?"Not sure what "internal image" exactly refers to. Glafkides' book is "Chimie et physique photographiques", Paris 1967. There is also an English translation available. I think it's this one:
Glafkides, Pierre. Photographic Chemistry, 2 volumes, London: Fountain Press,1960
Sergey Vorobyov

New developer for PFG-03m

Post by Sergey Vorobyov »

Your formula of developer is interesting, but it consist KBr. This chemical may be disturber for PHISICAL developing. And this developer need check too.
You read old book for photography! There are many interesting formulas in old books!
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