The Film Grain Looks Weird. Is it Reticulation?

The other day, I was scanning a roll of film I developed and I noticed that it looked different than usual. When I magnified it, I saw what looked like a series of ridges and valleys, resembling the cracked mud of a dried up riverbank. Well folks, it looks like my film’s experienced reticulation. I'm Andre, Customer Experience Manager here at CineStill, and today I’m going to talk about what causes film reticulation and how you can avoid it.

Now a few photographers might enjoy the look of reticulated film, but a majority of us would see it as an undesirable defect. Reticulation is simple to avoid if you pay attention to your processing. But before we go into that, let's talk about what reticulation is and what causes it.

WHAT IS RETICULATION? WHAT CAUSES IT?

Any conversation about reticulation benefits from a basic understanding of the structure of film. At a base level, a roll of black and white film consists of grains of silver halide crystals suspended in a gelatin-based emulsion, coated onto a clear-ish base of acetate or polyester.

Many of you may have never experienced film reticulation, and that’s great! For those that have, reticulation has 3 main causes. The first and most common is a sudden fluctuation of temperature greater than 10°F-15°F. When we develop our film, that gelatin emulsion layer swells as it absorbs chemistry or water. If we shock the film by, say, pouring into our developing tank a chemical or water that is substantially colder than the previous step, the emulsion contracts rapidly, causing a clumping together of the silver halide crystals.

Another common cause of reticulation is ph shock. Due to the high alkalinity of many developers, a shift in ph of over 7 can cause some films to reticulate. Our Df96 B+W Monobath solution is alkaline and has a careful concentration and balance of certain chemical components. As it oxidizes, that balance can shift and this increases the likelihood of reticulation, which is why it’s important to keep air out of the chemical storage bottles.

The last potential cause of reticulation is the use of distilled water for a rinse. Because distilled water does not contain additional minerals or electrolytes, osmosis causes a rapid transfer of chemical compounds out of the emulsion, causing the emulsion to shrink, and sometimes leading to reticulation. The extra minerals or electrolytes in tap water cause a slower transfer of chemicals through the emulsion and can help prevent a rapid shrinking.

Cubic grain films are more prone to reticulation, whereas T-grain films are less prone to reticulation due the unique structure of their emulsions. The emulsion layers don’t swell as much, but that also means that their processing times are often longer than with cubic grain films, especially the fixing step.

HOW TO PREVENT RETICULATION:

Okay, so large temperature shocks when processing film are bad. But how large is large? To avoid reticulation, you’ll want to ensure that there’s no more than a 10F difference in the temperature of the steps in your process. That includes water if you use it as your stop bath between the developer and fixer, as well as your rinse water after fixing.

It helps to pre-measure your chemistry before you begin processing so that you can confirm the temperature of each step ahead of time.

What if you’re processing at a higher temperature, like push-processing with our Df96 Monobath solution? This can be really easily controlled with something like the CineStill TCS-1000, which can be placed directly into most photographic chemicals to temper them.

If you don’t have one yet, that’s fine too, of course. Just make sure to insert a thermometer into your pitchers/bottles of chemistry to ensure that subsequent steps aren’t more than 10F cooler than the prior ones.

What if you like to wash your film after processing under running water? Here at CineStill HQ, we love having an in-line temperature gauge for our lab sink, but you can sort of DIY this at home by placing a thermometer under the running water of your sink, ideally one with a mixer tap, and adjust until the water temperature is close to the processing temp.

Again, this doesn’t have to be exact, but try to get it within 10F. At this point you can stick your thermometer into your developing tank while the water circulates. And keep an eye on it to make sure the water temperature doesn’t drop dramatically.

If you want to conserve water or don’t have access to running water wherever you process your film, you can use the Ilford Washing Method, which we covered in our video on washing film. Just make sure that the water you’re using to fill your developing tank with is near your processing temp.

My Film Was Reticulated. What now?

Unfortunately, you can’t undo reticulation. If you have an image that has been reticulated, you can scan it or print it with more diffused light by using ground glass. A couple inches between the light source and the film. This will help smooth out the micro contrast that makes the grain structure more visible.

And that’s about it, really. Many of you may never have experienced film reticulation, and the above steps are more or less what you do naturally. And if so, great! But for those who’ve been wracking their brains trying to figure out why their film came out so weird, I hope this helped.

Hungry to learn more? Check out our Film Tips playlist on YouTube here. If you have any questions, feel free to email us at support@cinestillfilm.com