5 Tips for using Fixers
02/10/18 22:44 Filed in: Fixing
Fixing? Surely there's nothing to it right? I mean, you just dump the film or paper into the fixer after stop bath, swish it around for a couple of minutes and wash right? Well my friend, you couldn't be more wrong. "Fixing" the photographic negative or print removes the undeveloped (and therefore unexposed) silver halides from the image. If we didn't "fix" paper then the image would deteriorate quickly through time. With film it's actually opaque until fixed. There's things to know about fixing so here's 5 tips.
When I first developed films and paper, I was eight years old. My father showed me what to do and explained that you fix the film for two minutes. Then, when I processed the paper he had me fix it for two minutes also! That seemed easy enough right? But little did I know there was a lot more to it. I was only scratching the surface of fixing. So today I pulled together a few of my favourite tips for my readers.
Tip 1: Dilute fix for film and paper differently.
Film and paper use very different amounts of silver halide in their emulsion; film having a lot more. The purpose of fixing is to remove the undeveloped silver halide and so you need a stronger fixer for film to remove more. For example, Ilford Hypam, a rapid ammonium thiosulphate fixer, uses dilution of 1+4 for film and 1+9 for paper. Don't try the same dilutions if you want good results!
Tip 2: Never reuse a film fix for paper.
Some people try to use the same fix they've used for film for the paper! Film, due to the concentrated silver halides in the emulsion dissolves more byproducts in the fix than paper and these byproducts can stain paper. Keep your fixers for film separate from your fixers for paper. Fix for film is a lot stronger too and bleaches the paper image. Best keep them properly diluted and apart.
Tip 3: Don't use hypo with modern films.
Back in the day we used sodium thiosulphate or "hypo" to fix film and paper. It came as large clear crystals we would dissolve in water. But, in those days film was different, simpler, and hypo could do a great job. Modern T-grain films such as Ilford Delta and Kodak T-Max need a more powerful fixing agent to dissolve out the modern silver halides. We can't use the older hypo anymore and instead have to use ammonium thiosulphate. It is the modern so called 'rapid' fixers that use this chemical. So, if you are a seasoned photographer that uses older films like Ilford FP4+, PanF+, HP5+ or Kodak Tri-X, and you want to make your own fix cheaply, use the sodium fix, otherwise stick to rapid fixers. Oh, old fashioned hypo does a fine job with paper which has changed little over time.
Tip 4: Use alkaline or neutral fixers for staining developers.
I use pyro and pyrocatechin staining developers such as PMK, Pyrocat-HD and 510-Pyro. They always put a smile on my face whenever I print negatives with beautiful high tones. These high subtle nuances are difficult to obtain with normal metol based developers. The quality of the high tones is due to the delicate stain left by the developer on the negative. This stain is crucial to the advantages of these pyro developers. Acidic (or what you might call normal) fixers reduce this stain. Therefore use a neutral or alkali fix like TF-2, TF-3, or TF-4. I give two formulas in my book to help.
Tip 5: Alkaline fix = Archival photographs.
I encourage all my darkroom friends to use an alkali fixer for their work whether they use staining developers or not and I favour its use for paper fixing. This is because alkali fixers wash out of the film and paper emulsion much more readily therefore supporting archival quality. Any fix that is not washed from the negative or paper will, with time, leave unsightly stains and ruin the photograph. I, for one, want my photographs to last a long time so archival permanence is important. No brown and unsightly stains on my negatives or photographs! Alkaline fix is the rule of the day. I hope it is for you too!