Separol two-bath

pbpb · 2007-12-05T12:17:09+00:00

Hallo! Ich möchte mit Moersch Separol HE und S in die Zweibadentwicklung einsteigen. Dazu hätte ich zwei Fragen: 1. Im neuen Datenblatt wird angemerkt, dass...

pbpb

Hello! I’d like to start using a two-bath development process with Moersch Separol HE and S. I have two questions about this: 1. The new data sheet notes that, with these products, the alkali and developer can also be prepared separately. Does anyone have any experience of how much this method extends the shelf life of the stock solutions? For example, W. Moersch’s SE3 Cold developer has a shelf life of several years after opening because the developer substance and alkali are kept separate. And what is the actual shelf life of the powders? In principle, I could also weigh out small amounts of powder each day for my daily needs (I have a darkroom, laboratory scales, etc. I develop film every few weeks, so shelf life would be more important to me than the 5 minutes’ work involved). 2. Development in the order He -> Soft is recommended. Is it possible to first determine the correct exposure time in the He bath and then keep this constant without any issues when experimenting with different development time ratios in He : S (for the same total duration, i.e. full development)? Or does the exposure time need to be recalculated each time the development times are varied? I’ve even read somewhere that with two-bath development, the exposure time should be determined by developing in the *second bath* (or does that only apply to a soft primary developer?). (3. Has anyone actually ever experimented with the possibility of repeatedly saturating the paper with developer and conducting the development in a separate alkaline bath? See the second post at http://www.apug.org/forums/forum216/34435-...development.html ) Regards Patrick

cfb_de

Hi Patrick, The separate preparation method should actually work. Have a word with Wolfgang about it. Regarding your second question about the partial approach: that almost certainly won’t work. Each component most likely consists of more than one ingredient (I don’t know Wolfgang’s recipes). Therefore, when taking partial quantities, you will always end up with different concentration ratios due to the varying bulk densities of the various chemicals. With the resulting unpredictable development outcomes. Best regards, Franz

pbpb

Hello Franz, First of all, many thanks for your prompt reply! I put your advice into practice straight away, but wanted to wait for the development results and my enquiry to Wolfgang Moersch before briefly sharing them here for others who might be interested. So: According to WM, preparing the solutions separately works in principle. However, the formulation of the developers has since been modified to such an extent that there is now hardly any difference in shelf life between preparing them together and separately. Anyone who still wishes to use the separate process must bear in mind that the contents of the green sachet (alkali, sulphite) can only be completely dissolved in 1000 ml of water. The mixing ratio when preparing the working solution must, of course, take this into account. And with the separate process, the starter must be added to the contents of the small sachet. I have already made my first enlargements and am very satisfied with the control over contrast offered by two-bath development. However, some of my Adox CHS50 films developed with Finol apparently have too high a contrast for use with Adox Nuance fixed-grade paper. Here, WM has provided the important tip that the rinsing time during negative development was probably too long, causing the stain to become too dense. Therefore, when developing with Finol, rinse for under 6 minutes! Or possibly shorten the negative development time. Best regards, Patrick