The film has a nominal speed of ISO 100/21° when processed in the dedicated Foma R100 development process. Other processes can cause deviations from the nominal film speed. It is therefore recommended to verify the real film speed by doing preliminary tests in such cases.
Foma R100 B&W Reversal Developing Kit - 8x330ml
The Foma R100 B&W Reversal Developing Kit is a special set for the processing of black-and-white reversal films such as Fomapan R100 and Adox Scala. The set contains four components including a hydroquinone based film developer used for 1st and 2nd development, an ammonium thiosulphate based fixer and a bleaching and cleaning bath. The processing set serves for the preparation of 8 processing baths of 330ml each. With each bath one to two R100 films can be developed, as a result approximately 8 black-and-white reversal films can be developed with this kit.
Unlike the normal black-and-white negative developing process, the exposed silver in the image remains clear and the unexposed areas turn black. In order to do this, the exposed silver areas are developed and washed away and the remaining unexposed silver areas are then exposed (second exposure) and once again developed, then finally fixed. In this way, you get a slide with prefect gray tones.
The supplied bleaching bath is free of potassium bichromat. Full mixing and usage instructions are included, along with a developing time table for Fomapan R. Other films can be developed by slightly varying the first developing time (5 to 11 minutes).
Attention: the reversal developing process is complicated! There are a few things that you need to watch out for in order to have good results. Since potassium bichromat can no longer be used, the bleach must be handled with utmost care. The bleach used in this kit goes bad very quickly after opening. Therefore you need to mix the bleach just before you use it - preferably you should mix it during the developing process. Be sure to bleach your films for a sufficient length of time. It is also very important that the film gets sufficient light during the second exposure.