Cross tests of 17 films 120 / 6 developers

Origin of the project

Project presentation

Practicing photography since a young age, having started with B&W film with my father, for many years I jumped from one film to another, from one developer to another, following what came to hand. or what was available at the local store. All this, without really trying to study what differentiated the products and the results obtained. The negatives were then disparate, and not necessarily with the expected specificities.
A few years ago, I started doing more precise tests, focusing on a few film models, and one or two developers. Then came the day when I decided to launch into a big comparison. Certainly, this great cross-test is not exhaustive. It would be too time-consuming and too expensive to try everything that exists on the market. The film/revealer pairings would be huge. So I decided to limit myself to products that can be found commonly and quite easily throughout the world. I chose five brands of 120 format film, with sensitivity between ISO 25 and 400. I have deliberately eliminated the few higher sensitivity films, although I use them from time to time, notably the Delta 3200. A limit had to be set. As for developers, I limited myself to six references, some in powder, others in more or less concentrated solution.

Shooting process

A test of this scale and this type should make it possible to highlight the differences between each pair of film/revealer. It is therefore necessary that all steps are carried out as identically as possible.
The shots were therefore taken in one go. In order to guarantee the results and limit failures, three instances of each film were produced. Indeed, having chosen six developers, I estimated that each film could be cut into three parts of approximately 25 cm. So I needed two complete films to carry out the tests. Another film was therefore made in case of development problems. The shots were taken in a studio, with constant lighting. in continuous light generated by two Gemini 500R torches with two 80x80 cm softboxes. The objects in the scene were mainly selected according to their rendering: shiny, matte, chrome, brushed, transparent... A color chart was also attached to the wall in order to obtain a range of grays and thus be able to study the « conversion » of this or that color. The shooting equipment was chosen to guarantee stability at all times. test and a total absence of vibration or displacement. A solid studio stand, fixed to the floor and ceiling, was put in place. The shooting equipment used was my Linhof Technika 70 with its wonderful Xenotar 100/2.8 and 6x7 backs.
Note that the lens shutter was serviced a few months before the session, so the speeds were safe and consistent. To once again guarantee the results, a remote trigger was used. Of course, the focus and the aperture (f/16) were not modified throughout the session. The minimum shutter time, for its part, was chosen so that the least sensitive films had an exposure of one second to avoid a Schwarzschild effect.
Then, the law of reciprocity was used for higher sensitivities.

Development process

Just as for the shooting, the film development stage was carried out within short deadlines and in the most homogeneous conditions possible (heating regulation at 20°C). Each batch of the same film was separated into two: two films for development, a backup film just in case. This somewhat exaggerated approach was useful twice, with the development results being disappointing and doubtful. Each of the two selected films was cut in the dark with a paper cutter that I had attached to a board and installed a stop in order to have identical film lengths. Then each piece of film (6) was placed on a coil and in a separate Jobo tank. The developers, prepared scrupulously following the manufacturers' instructions, were produced in large quantities in order to guarantee their effectiveness and durability over time. All developments were single-use. Only the fixer (Ilford Rapid Fixer in 1+4) was replaced approximately every 9 pieces of film (3 films).

The process was carried out in an identical and precise manner: development at 20°C following the planned time, with a Jobo CPE-2 at rotation speed 1, rinsing for 4 minutes with a specific Jobo hose, fixing for 10 minutes, rinsing of 10 minutes.
The six pieces of film from the same film were developed successively and in cascade at once. The tanks being identified by a number corresponding to a developer, it was impossible to invert cells and make mistakes in the results.
Once a complete film model was developed, I would move on to the next model and so on. Nine days at full capacity were necessary to achieve the developments. Important note regarding development times and dilutions:
The times I selected were calculated using a weighted average formula, which is an average where the time recommended by the manufacturer falls into 70% of the calculation, the remaining 30% being the recovery of three values (3x10%) of times found on the internet, in books or feedback from photographers, without exceeding +/- 20% of the manufacturer value.

Analysis process

Once all the negatives have been processed, dried and identified with a felt-tip pen with the film model (this may seem stupid to some people, I might say, because the name of the film is mentioned on the side... well not all!) and the developer used, I cut into 21 cm strips and classified in crystal sheets. Not having a professional Imacon type scanner, but only a fairly average Epson V850, we had to find the appropriate and unique setting that would be suitable for each film. Each piece of film has therefore been scanned with particular settings, at 3200 dpi, in the same way, then saved and identified, classified by folders, then cropped identically in Photoshop. To maintain maximum quality, IR dustproofing has been disabled. The raw scan has been preserved, and a high definition exported as JPEG for downloading. A copy of the high definition was made, and the levels rebalanced based on the white and black of the test pattern and controlling the histogram. This ultimately allows to realize the rendering and the softness or hardness of the gray gradients and the influence on different areas of the image depending on the developer/film pair, while ignoring the level of transparency of the support and its coloring.

Grain analysis

This analysis was not planned at the start of the project, for technical and material reasons. Then, during the project, I invested in a laboratory trino microscope for other needs, which allowed me to consider taking pictures of the grain of each film having been developed in each of the developers. After a few tests with a simple webcam and then a dedicated astrophotography webcam, I realized that the resolution was not sufficient and the rendering was very blurry. So I bought an adapter for the microscope in order to attach an EOS mount. In order to gain a little more precision, I used an EOS 40D. Indeed, the 5Dmk2 and mk3 used to carry out the tests did not allow for a wide enough field, the adapter being quite narrow. The form APS-C is therefore more suitable. To guarantee both speed of acquisition (everything is relative...) and avoid any vibration, the device was controlled remotely by computer, with aiming on screen in order to trigger once focus is achieved. Once again, in order to resolve as much as possible the size and shape of the grains (when there are any?), I used a 100x immersion objective in an oil bath, in order to gain optical quality. The final ratio is 1600x.

Developers in the presence

The choice fell on 6 developers from 4 brands.
They were selected based on their general availability, their type (powder or liquid) and their expected specificities (contrast, acutance, etc.). the Ilford ID11 was not selected, because it was very close to the Kodak D76.

Kodak D76

Relatively identical to ILFORD ID11, this developer is presented in powder form to be diluted. The preparation of the D76 used for my tests was rigorously carried out following KODAK recommendations: Dilution in 80% water at 55°C, mixing, then adding the remaining 20% water.

Kodak XTOL

This developer is presented in powder form in 2 bags, to be diluted to make a stock preparation. The preparation of the XTOL stock used for my tests was rigorously carried out following KODAK recommendations: dilution at room temperature and use exclusively in a single bath.

Kodak HC-110

This developer is presented in liquid form, in a quantity of one liter. There are other packages of different quantities. However, it seems that in this case, the concentration of the product is not the same. The concentrate should be diluted in water at room temperature.

Here are the concentrate-based solutions:

• 1+15 (dilution A)
• 1+31 (dilution B)
• 1+19 (dilution C)
• 1+39 (dilution D)
• 1+47 (dilution E)
• 1+79 (dilution F)
• 1+119 (dilution G - unofficial)
• 1+63 (dilution H - unofficial)

Only downside, the concentrations being extremely high, and the quantities to be diluted sometimes very low, it is not easy to produce small quantities of developer, being safe and reliable as to the actual dilution. It is therefore better to prepare larger quantities to be sure to get as close as possible to the right dilution rate. However, the price per liter is ultimately very low compared to other developers (at 1+79, this comes to around €25 for 80 liters of developer in 2017!)

Tetenal Ultrafine

This developer is presented in liquid form in 250 ml or 1 l and allows you to prepare dilutions on average between 1+4 and 1+50. The results are often very soft and low contrast, with very fine grain.

Agfa Rodinal R09

Known as one of the oldest developers still on sale on the market, it is presented in concentrated liquid form, allowing dilutions of 1+25 and 1+50.
It is even possible to dilute it between 1+100 and 1+200 in order to reduce contrast.
It is a developer with high accutance, it is therefore preferred to reinforce the edge effects, and thus increase the appearance of sharpness of the films.

Ilford LC29

This developer is presented in liquid form in 500 ml. Its concentration allows dilutions between 1+9 and 1+19 to obtain fairly short treatment times, or 1+29 for economical use.
It is a developer that is very suitable for advanced processing of fast films.

The films in attendance

The choice was on 17 films from 5 brands. The selected models are all between ISO 25 and 400:

Kodak

• TMax 100
• TMax 400
• Tri-X 400

Ilford

• PAN F 50
• FP4+ 125
• HP5+ 400
• Delta 100
• Delta 400

Rollei

• PAN 25
• RPX 25
• RPX 100
• RPX 400
• Superpan 200

Foma

• Fomapan 100
• Fomapan 200
• Fomapan 400

Fuji

• Acros 100

In order to have the most reliable results possible, and to avoid potential errors and disappointments during development, each film model was purchased 3 times. The freshness of the films was checked, with expiry dates not having passed. The films were stored in the refrigerator before shooting and all then stored at 20°C from the start of the process.

Be careful not to pay too much attention to the dark tint of some raw scans. Indeed, some supports are very thick and dark, while others are very thin and very transparent. Good exposure management under the enlarger or during scanning will give the same results.

Note: The grain was photographed under the microscope on the same area on all films. The area chosen was based on the average density in order to best detach the grains, all films combined.

Grain rendering by developer

Rollei Pan iso 25

Rollei RPX iso 25

Rollei RPX iso 100

Rollei RPX iso 400

Rollei Superpan iso 200

Fuji Acros iso 100

Kodak T-Max iso 100

Kodak T-Max iso 400

Kodak TRI-X iso 400

Ilford PAN-F iso 100

Ilford FP4 iso 125

Ilford Delta iso 100

Ilford HP5 iso 400

Ilford Delta iso 400

Foma Fomapan iso 100

Foma Fomapan iso 200

Foma Fomapan iso 400