Ing. Koblic MPB (outdated film developer)
during and after W.W.II. photographers in the Czech Republic suffered from lack of fresh films - in fact one wasn't able to buy anything else than outdated film or paper. famous photography-oriented Czech inventor and chemist Ing. Premysl Koblic (aside from his famous Pextral developing method) formulated a special developer intended to use with outdated films.
so it's time to tell the whole world about it .)
Metol - 4 g
Sodium sulfite (anhydrous) - 16 g
Disodium phosphate (.12H2O) - 4 g
Borax (sodium tetraborate) - 8 g
water to make - 1000 ml (pH should be 8.5)
developing time suggested for the first film is around 8-15 min at 18 °C.
should be stored up to 6 months (and maybe more).
used developer can't be stored.
amount of Disodium phosphate can be altered up to 70 g/l - it acts as a restrainer of a fog&haze and other negative effects of long-time stored film.
film's speed will be slightly better than D-76 and negatives will be very sharp, fine grained, gelatine layer is very clear. prints should look crisp and sharp without annoying edge-effects caused by many actuance developers.
Delta 400 negatives have as good tonality as souped in DD-X but are super-sharp (can be seen even on 5x enargements as a huge difference).
btw - it can be diluted 1+1 with approximately doubling the development times, giving more compensation. using at higher temperatures than 20 °C cannot be recommended because of metol's soft-working nature.
btw2 - concentrated (3x ?) solution to be diluted before use can be made easily.
some sample shots from delta400 @ mpb 1+0 are attached. scanned enlargements from ilford mg iv rc and adox easy print in dektol made with condenser enlarger.
Delta 400 looks awesome, and very sharp, in MC-TEA, which is also a low-sulfite, low-pH developer. For me, the price of low grain and high sharpness was a slight reduction in speed. Totally worth it, though.
maybe i haven't said that loudly enough but biggest advantage of MPB is given tonality.
Interesting formula. Until you explained the presence of the Disodium Phosphate, I was at a loss as to its purpose. And another oddity that appears to me is the use of Metol with sodium sulfite in anhydrous form rather than dessicated as seems to be, by and large, customary. The anhydrous seems to be primarily used with hnydroquinone. (Ron must be rubbing off on me a little.)
Thank you for sharing it with us.
Nice images, I wonder what the best formula for most beautiful tonality would be
Is metol substitutable with another developer?
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Anhydrous is the same thing as dessicated. It it just another word for the same thing.
Originally Posted by Christopher Walrath
should be but you have to work out the proper amounts for yourself (I just don't know, right?)...
Originally Posted by Athiril
Lukas 87: What's capacity of the developer - how many 135 flilms in one liter, please?
one liter of working solution is capable of developing four 135-36 films
it is important to note that used solution can not be stored - you have to develop all four films quickly one after another.
also - increase developing time by 10 % for each developed film.
however I have no experiences with reusing MPB - I make 3x stronger mix and then use it "one shot".
hell, this developer is for "expired film", it's not outdated... don't know where I had my brain when I wrote that