Abstract

Cross processing the 16mm format of the Ektachrome re-introduced in October 2019 with emulsion number 7294 in Tetenal’s Colortec C-41 Processing Kit by hand using a Lomo tank was successful and produced a green-cyan colour shift specifically in the midtones along with high contrast and high saturation.

Clare skating in the Bowl of Bridges Skate Park.

Introduction

There were many challenges and new avenues I decided to explore with my third film in 16mm, Quad Euphoria. The most significant was placing myself firmly behind the camera and documenting a snapshot of the lives of others. There were many technical aspects that motivated me to do this project. Venturing into recording and editing audio, foregoing any use of handheld, but rather to resort to using a tripod, a dolly made from chipboard, skateboard wheels, and plumbing pipe, and even variously taping the Bolex to a bicycle. But another technical challenge was the decision to venture into colour.

Creating a motion picture in colour always presents more technical challenges in comparison to black and white, regardless of whether the medium is film or digital. With black and white, you eliminate all the variables involving colour temperature, plus or minus green, and the fact that all colours you capture will be reproduced. From an artistic perspective, black and white is a simple way to give whatever you capture a unique look. You can make something look good in black and white with less money and in a rudimentary way. With colour, it's a different story.

To capture and reproduce colour with 16mm today, there are a couple of options. The most apparent choice is to use one of Kodak's Vision3 colour negative film stock. It's a popular option still used today on professional productions and is available in a variety of speeds for both daylight and tungsten light. However, Vision3 stocks present a lot of challenges if you intend to hand process them. Firstly, despite being a colour negative emulsion, Vision3 stocks are not intended for C-41 chemistry that would be used for film intended for still photography. They instead use a process called ECN-2. Although ECN-2 features the same processing stages as C-41 - develop, bleach, and fix, - all stages are performed at a variety of temperatures, and there is a more frequent use of stop baths and rinsing the film. It is possible to develop Vision3 stocks in C-41, but it only produces inferior results without lending anything significantly interesting to the final image.

Secondly, Vision3 stocks have a unique anti-halation layer. The purpose of this layer is to stop any unwanted light reacting with the emulsion from the base side. Whether it be to stop light reflecting off whatever is behind the film when being exposed and allow film to be coiled up on daylight spools to be loaded in subdued light. Every film has this layer and is typically removed when processed in the standard processing chemistry or with just some water. But the anti-halation layer on Vision3 stocks comes in the form a carbon backing on the base called rem-jet. This is not removed by the chemistry alone, instead the film must undergo a rigorous chemical pre-bath before the emulsion can be developed. If this step is skipped, not only will the anti-halation layer remain on the film, but the negatives will be covered in sticky black carbon ruining all the footage. I've heard many reasons why Kodak's colour negative motion picture film stock features this anti-halation layer, ranging from preventing static discharge occurring on the emulsion due to the film passing through the gate at high speed, to requiring more protection from light when use daylight spools. But rem-jet isn't present on other motion picture stocks, including black and white and colour reversal films from kodak, which puts me in doubt of these claims. Hand processing Vision3 stocks and removing rem-jet isn't impossible, if you have an ECN-2 kit, but it is nevertheless among one of the more challenging films to process and is best left to an established lab.

An alternative to Vision3 stocks provided by Kodak is Ektachrome. This is a colour reversal film available in both still photography and motion picture formats. Currently, it is only available as a daylight balanced 100 ASA stock available in 100ft and 400ft lengths for 16mm. This is not to be confused with Kodachrome, a different colour reversal film discounted in 2009. Kodachrome used the K-14 process exclusive to the film and was held by limited laboratories that are also no more. Ektachrome on the other hand is a colour reversal film that uses the E-6 process, the commercially available set of chemicals for developing colour positives for Kodak films and other brands such as Fujifilm. Not unlike C-41, it is available in kits for hand processing with each solution at the same temperature. The E-6 process itself makes Ektachrome a far easier film to process by hand than the Vision3 stocks. Furthermore, the motion picture stocks of Ektachrome have no rem-jet backing, making them even easier to process and experiment with.

Colour reversal films may be designed to be developed as a positive using E-6 chemistry, but they can also be developed as a negative using C-41 or ECN-2. This is referred to as cross processing and despite being the incorrect chemistry it can be performed deliberately for artistic reasons. Not only does processing colour reversal films in C-41 produce a negative image, but it also tends to produce an intense colour shift. The results of this effect are often emulated digitally, most notably the X-Pro II filter featured on Instagram. The type of colour shift depends on the specific film stock it is applied to, and the effect varies depending on how the film is exposed, the brand of chemistry used, and the temperature of the solutions. A good example of how intense the effect is, and the variety of results it can produce can be seen with Fuji Velvia. This film is currently available in two speeds, 50 and 100 ASA. Both films produce similar results when processed in E-6; high contrast and very saturated colours. But they yield very different results when cross-processed; Velvia 50 has a cool green-cyan tint, whereas Velvia 100F has is a warm red-magenta. How and why this effect occurs is something I still don't understand. Due to how unpredictable the results can be, only a handful of labs will intentionally cross process film, and fewer still - if any - will apply the technique to motion picture stocks. But its that unpredictable nature and the relative ease of the C-41 process that makes it a desirable technique to carry out by hand. But most crucially, cross processing provides a unique style to a colour image when other factors such as lighting and mise en scene are not in control as was the case with this project.

The reason why I've made this blog is to document the results of cross processing 16mm Ektachrome. In 2018 Kodak reintroduced Ektachrome in 135, and other formats the following year including 16mm. The emulsion number for this stock is 7294. Before being discontinued in 2012 16mm Ektachrome had the emulsion number 7285. This means the Ektachrome currently being produced by kodak is an entirely new emulsion with different characteristics to the previous iteration. And after copious browsing I haven't found anyone who has processed 7294 in C-41 so I have no idea what to expect.

The closest thing I can find are these results from Matt Moloney who cross processed the new 135 format of the emulsion. Yielding a cool colour shift.

Method

For this experiment I'll be processing three 100ft rolls of fresh 16mm Ektachrome 7294. I'll be using a 2.5 Litre Tetenal Colortec C-41 Developing Kit. I've previously processed a 135 roll of Fuji Velvia 100 in Tetenal's 1 litre kit using a Patterson Tank and received stellar results. To process each 100ft roll of 16mm, I'll be using a UPB-1A universal developing tank from Leningradskoye Optiko-Mekhanicheskoye Obyedinenie, also known as a Lomo tank. This tank consists of spirals that can hold two 15m lengths of 16mm film. The tank can process a 100ft roll of 16mm at a time using 1.8 litre baths, so the 2.5 litre kit is more than enough. Tetenal provides recommended processing times for each bath depending on the amount of film being processed and the quantity of the solution. In terms of surface area, 100ft or 30.5m of 16mm is equivalent to 9 rolls of 135. So, judging by the recommend times I believe I can process the film with a 2 litre solution of each bath according to the times provided in each column.

Even though Tetenal's instructions state the blix can be used straight after the developer, I'll deviate from this by thoroughly rinsing between the developing and bleach fixing stage, effectively performing a water stop bath. Although this is not necessary when developing colour negative film in a Patterson tank, Ektachrome has much less latitude, so over development can have worse results. Also, the Lomo tank takes longer to drain, and even then, it can be very difficult to ensure all the developer has been removed from the tank.

Results

The results were interesting. Whilst the film was still wet, the emulsion side had a dull orange appearance, whereas the base reflected a blue-violet colour, but appeared orange when light was pass through it. Once the film was dry, this blue reflective effect disappeared. Upon close inspection, the images formed appear to be magenta where the image is dense and orange where the image is thin.

Before sending the footage away to be scanned in its entirety by Garvan Tohill from HappyIreland Productions, I scanned a snippet of the frames on my flatbed scanner. When scanned and inverted to a positive image the exposures have a green-cyan colour shift.

After receiving the 2K Scan my feelings were mixed as always when you see what you've shot for the first time. What is notable is that most of the colours are neutral, with most of the green-cyan colour shift corrected. These results have contributed to this belief I have. When cross processing, the effect is at its strongest when the negative is thin. If it's well exposed or dense, the colour shift will persist, but there's enough density within all the couplers, the effect can be corrected once the image is in its digital form. This is good if you want to salvage neutral colours when your colour reversal film has been cross processed accidentally. But if you're like me and you’re cross processing deliberately because you want those garish results, it can be underwhelming. The technology behind creating digital images is designed to capture as large a colour gamut as feasible, producing the most precise and useful results. And it seems that modern scanners are so good that the effects of cross processing can be easily corrected with auto exposure.

Also, I'd like to add a bit of insight from exposing Ektachrome. When I got the scan back, the footage from the last two rolls had blown out highlights. I felt confident that I metered my exposures correctly, so I initially suspected that the rolls were overdeveloped, scanned incorrectly, or suffered heat damage. But upon reflection, I remember taking reflective readings with my light meter on my first two days of shooting, and incident readings on the days where the footage appears to most overblown highlights. As Ektachrome is a reversal film, it has very little latitude for exposures, and it seems that having a light meter simply isn't good enough, you must know how to use it. I distinctly remember Matthew Libatique in this video talking about his preference for reflective readings as reflectivity contributes more to what you're capturing on reversal film as opposed to how much light falls on the subject matter. Fortunately, all the shots that made it to the final cut that had exposure issues were easily corrected using DaVinci Resolve’s colour wheels. By the way, after merely adjusting the gamma, more of the effects of cross processing returned, with images starting to reflect the results from Matt Moloney.

An outtake from the project demonstrating the results of cross processing in motion.

conclusion

This entire documentary was a long demanding project, but it was very satisfying. I believe the results from cross processing created a visual style that really suits this snapshot of four roller skaters in Belfast. By the way during the time I’ve been writing this blog, I was pleased to discover Kodak Film Lab Atlanta cross processed Ektachrome 7294 in ECN-2 and shared the results here.

If I were to do this again, or the advice I’d give to anyone interested in repeating this process would be: shoot in low contrast lighting situations such as an overcast day, use reflective readings for exposures, extend the development times by processing at 30°C, and use an acid stop bath to ensure development has stopped. My plan now is to experiment with colour further and venture into a different alternative process called bleach bypass. So, stay tuned for that and I hope you enjoy watching Quad Euphoria!

Cross Processing 16mm Kodak Ektachrome 7294 in tetenal colortec C-41

Abstract

Introduction

Method

Results

conclusion

Bleach Bypassing Vision3 50D 5203 with an ECN-2 kit by Quiet We're Dreaming