FX 1 Developer - The First

In the early 1900s the tool of the professional photographer was large format cameras such as 4x5 inch, 7x5 inch and 10x8 inch. The negatives were often contact printed directly onto paper. This maintained good contrast, tonality, and negated any sign of grain. But these cameras were big, heavy and bulky. Ansel Adams was famous for carrying his large format camera equipment on the back of a donkey (apparently named Mistletoe) up the hills of Yosemite. Everything was heavy, not just the cameras but the big tripods, the lenses and even, back in the darkroom, the enlargers. Photography was not something the average person could partake in easily. Photographers in those days tended to be professionals.

Then came the much handier 120 sized film, introduced in 1901. It was ~61 mm wide. It made slow inroads into the photographic world and became particularly popular with press photographers and the new photographic amateurs that saw it as a way into this interesting hobby. 120 was a wonderful size because of its light-weight, portability with smaller cameras, and its “multiple frames on one film” ability. On a single roll of film you could make several photographs. This was a huge jump in usability.

The booming film industry was of course using black and white film too. Cinematographers and directors were happy using 70 mm wide film strips in the late 1800’s but then, by the 1900s, they too started looking for a more portable and cost saving format. In 1909 they chose a new film size of 35 mm. The size was easy to come by. 70mm movie film could be sliced down the middle and stuck together therefore doubling the film length and halving the cost per minute for movie makers. Perforations were made on both edges of the film to allow easy projection.

For 35mm stills photography, photographers had been using various cameras since ~1905! But Leitz started making their famous Leica cameras in 1925 and released the first ever system camera, the Leica 2 (with interchangeable lens system) in 1932. This was another breakthrough in usefulness. Small, portable cameras with easily changed lenses.

But most photographers used large format with a few medium format. The popularity of 35mm must have started to grow though because Kodak decided, in 1934, to release their first 35mm film to the public, what they called the miniature “135” size film. D-76 was recommended as the developer of choice probably because this was the Kodak developer used by the 35mm film industry. D-76 was a good developer which minimized grain whilst maintaining decent film speed. Many companies made variants of D-76 for their film development and it became the de facto standard developer.

The problem

But film manufacturing companies such as Ilford, Kodak, and Adox had figured out there was a problem. They realised that when they coated the small 35mm film with the same photographic emulsions used on their large or medium format films, print enlargements were grainy and sharpness was poor. This lack of sharpness and contrast was due to the high enlargement requirements of such a small format and was compounded by photographers using the recommended fine grain solvent developers such as D-76, D-23, D-25. All these developers were good at reducing the natural grain of the film but lacked good sharpness and, especially, fine detail. When the 35mm negative was enlarged fine detail was rendered poorly.

The only way it seemed, to get sharp, impactful, detailed prints, was to use large format negatives and therefore low enlargement, or no enlargement at all by contact printing.

Emulsions then improve in sharpness

However, emulsions were slowly improving. With the growing popularity of 35mm photography, especially after WW2, new updated film emulsions had to be designed with the smaller negative and bigger enlargement factors in mind. The emulsion designers did good work and not only managed to reduce grain in new films but also reduced emulsion thickness and added more silver creating what Crawley called “compact emulsions”, meaning thin and high in silver halide content. This helped to improve the sharpness of the negatives and of enlargements, the thinner emulsion creating less diffusion of light passing through it and the rich silver content creating bolder contrast lines when enlarged and improved tonality. Ilford was one of the first companies to manufacture thinner, sharper emulsions with their PanF and Adox too was doing the same in the 1950’s. But as far as film developers were concerned there were few designed for the small (called miniature) format. The 1930’s Beutler developer stood out. It is said it was designed for 35mm film and many serious 35mm photographers started using it. It was a sharper and more compensating developer than the solvent types.

Crawley’s research

By the early 1960’s Geoffrey Crawley started publishing his research on developer formulation, sharpness, and how the impact of 35mm negative enlargements could be improved.

Crawley used four terms in his writing:

1. Acutance. A scientifically measurable quantity, directly correlating to the measurement of density gradients.
2. Resolving-power. How well a lens, film, or developer (or all three!) reveals detail. It’s something you can actually scientifically measure with a resolution chart.
3. Sharpness. Crawley said sharpness is a perception and is typically assessed from a normal viewing distance relative to image size. At the micro-level it can be measured by acutance. Crawley said “When acutance is high, sharpness is good.”
4. Definition. Unlike sharpness which is judged at normal viewing distance, definition is judged up close to the photograph - it is a measure of how clearly fine details can be seen. Crawley said “When the acutance with which fine detail is rendered is high, then definition will be pronounced good.”

We might notice something about the way these four attributes can combine. That is, the sharpness of the photograph might be good at a normal viewing distance, even if the resolution is poor i.e. there’s little or no fine detail. This is because acutance can improve sharpness on a macro level even if there is no detail on a micro level due to a poorer lens, for instance.

Crawley thought that developer formulators, up to that point, had mostly been concentrating on, what he called, the grain-speed interlock - minimising grain whilst maintaining good film speed. He decided that a third attribute of the negative should be taken into account, acutance. He formulated and judged his own developers with the grain-speed-acutance interlock in mind.

It was clear to Crawley that by increasing acutance there was an increase in grain, as compared to D-76, but he also noticed a psychological effect.

Grain

This psychological effect is important to photographers. What Crawley found was that if definition is good, i.e. there is good fine detail rendered by the lens/film/developer combination, and acutance is high then the increase in grain is masked by that detail.

Take a look at any photograph that shows a lot of detail. You won’t see much perceivable grain in that image. Now take a look at either a large out of focus area or an expanse of plain sky. You will now see grain because the brain is not giving its attention to detail anymore. As Crawley stated, “The grain in a sharp image is much less obtrusive than in a soft image. In every photographically produced picture, there are really two images, the intended image of the subject, and a secondary grain image; if attention is riveted to the primary image of the subject, the less the grain image obtrudes.” Crawley knew then that increased grain was not such an issue as previously thought.

My first use of Crawley developers

In those days, in the early 1970’s, I had never heard of Geoffrey Crawley, or read his writing from the early 60’s, some ten years before. But, even as such a young photographer I could clearly see this effect in my own work. I had started developing in my father’s D23 Replenished and for many years was perfectly happy with the results. When I had a good lens I felt my photographs were sharp although I did realise that detail seemed to be lacking. This lack of detail was unsatisfactory to me. Then someone told me to try Crawley’s Acutol. It was sold by a company called Paterson. “What difference would a developer make?”, I thought. But it did.

Acutol made a huge difference. I was amazed at the detail and sharpness of the results. What I thought had been sharp photographs were not. Acutol took sharpness to a new level. What was it that made such a difference? What was so special about this developer? The answer was simple enough. The new developer was an acutance developer and acutance now became my new best friend.

This was how many photographers became aware of Crawley’s work with developers, Acutol, and the Paterson ACU range of chemistry.

And so Crawley became famous for his acutance developers. He also released formulas for better solvent developers, which I’ll cover later, and even a monobath. But his initial fame came from FX 1 and his other FX developers. And FX 1 was his “high acutance” and “sharpness first” formula. Let’s take a look at it.

FX 1 Working solution:

Water 50C 750ml
Metol 0.5g
Sodium sulphite 5g
Sodium carbonate Anhyd. 2.5g
Potassium iodide 0.001% solution 5ml
Water to make 1 Ltr

• Add a pinch of the sulphite and dissolve before adding the metol.

• Best used with slow to medium speed films.
• For initial development times try 12 minutes and adjust from there.
• Use best technique for making the sharpest possible photographs. Any poor practice might be amplified by this sharp developer.

Notes on formulation:

1. Crawley followed Willi Beutler’s idea that in order to get good acutance one needed a strong alkali.

Up to this point many common film developers, such as the ubiquitous D-76, used Borax (PH 9.2) as the accelerator. This is relatively mildly alkaline and delivers a slow, steady, controlled development of the film, allowing more control over the developing highlights. Sodium carbonate (PH 11.5), used in this formula, is much more alkaline. It’s normally used in paper developers where development speed is quick and where we develop towards completion. It is a contrasty accelerator that can easily blow out highlights with metol. Used with a ‘normal’ amount of metol the strong alkalinity of sodium carbonate would provide too much energy to metol and the negative highlights would quickly burn out, even before the shadow development was complete! This is seen in the Beutler formula where contrast could be an issue.
Crawley says that photographers of the time knew Beutler was too contrasty and chose to half the amount of sodium carbonate (or even dilute the developer 1+1). He chose to half the carbonate in FX 1.

2. Developing agent reduction.

But Crawley wanted to increase the acutance even more than Beutler, after all, this was a sharpness-first developer. He understood that the Eberhard effect, the effect that caused Mackie (or acutance) lines, was caused by the reduced activity of developing agent on one side of a contrast boundary as compared to the activity on the other side and the subsequent transmission of developing agent and bromide restrainer across the contrast boundary within the emulsion. If he could just enhance this effect he would have more acutance and a sharper developer. So he reduced the amount of developing agent by a half.
This was a small amount of developing agent now. As an example, D-76 uses 2g of metol as developing agent in the working solution and FX 1 uses only a 1/4 of that amount.

Compensation

By Crawley reducing the amount of metol to 0.5g/Ltr he ensured that, between agitations, the developing agent would slow down quickly where it was working hard in the highlights, yet let the shadows continue to develop. Therefore there was some compensation to reduce excessive contrast.

Acutance

But local acutance was also increased. Bromide is a byproduct of development and the developing agent, metol, is restrained by it. When the bromide, from a high development area, permeates across the contrast boundary of a sharp line or fine detail it quickly restrains the small concentration of metol next to that boundary causing a light line to form. You might see these light lines in your photographs, especially on horizons when using acutance developers like diluted Rodinal.

3. Potassium iodide restrainer.

The trace amount of potassium iodide is very interesting. Potassium iodide is a restrainer like potassium bromide. Crawley believed that with certain, slow films the iodide helped improve acutance at the micro-contrast level i.e. the fine surface detail. He thought it should only be added if the photographer was using the highest quality lens and best possible skill to reduce any chance of camera shake (high shutter speed, tripod, etc). Because of the addition of iodide in modern films it’s probably not going to make a difference with all films these days so I recommend testing with and without this addition and assess it’s use.

4. The two reasons for the low levels of sulphite

The sulphite level was carefully formulated for two reasons. One reason was for film speed. It was known already that sulphite affected the speed of the film. The sulphite chemically etched away at halide crystals revealing deep latent development sites. These sites would not normally have been developed but the etching revealed them to the developing agent. Unfortunately, at high levels, sulphite’s physical development was a problem. At higher levels sulphite encouraged halide crystals that had not been exposed to light to develop! Fog! Thus restrainers had to be used to counter this effect and reduce fog. So the sulphite had to be kept low. Film speed is improved up to 100%. I tested FP4 Plus and saw an EI of 200 (+66%). With PANF Plus I saw an EI of 100 (+100%).

The second reason for the low amount of sulphite was acutance. Crawley believed sulphite regenerated metol. He said, “To prevent regeneration of the developing agency [sic] sufficiently to improve definition, the concentration of sodium sulphite anhydrous must be kept below 6g/Ltr.” But he stated that below 4g per litre the keeping properties of the developer were seriously affected. By preventing the regeneration of metol he again increased the acutance in those areas where the Eberhard effect manifested.

FX 1 was derived from the Beutler developer. Here is that Beutler formula:

Beutler formula:

Water 750ml 50C
Metol 1g
Sodium sulphite 5g
Sodium carbonate 5g
Water to 1 Ltr

Crawley felt the Beutler formula was too contrasty with modern films. Users of this developer developed with it at half strength where it becomes similar to FX 1 without the iodide. But, and this is a big but, at half strength the sulphite level was too low, according to Crawley, to maximise film speed.

Making an FX 1 Concentrated solution:

In order to keep well this concentrate is made up in three parts, A, B and C.

FX 1 Concentrate Part A

Water 50C 800ml
Metol 5g
Sodium sulphite Anhyd. 50g
Water to make 1 Ltr

FX 1 Concentrate Part B

Water 50C 800ml
Sodium carbonate Anhyd. 25g
Water to make 1 Ltr

FX 1 Concentrate Part C - Iodide solution
Potassium iodide 0.001% solution

• Use at dilution: 1A + 1B + 8 Water
• Add part C to working developer as follows:
• 30ml A + 30ml B made to 300ml with water then add 1.5ml iodide soln.
• 50ml A + 50ml B made to 500ml with water add 2.5ml Iodide soln.
• This concentrate should keep well (at least 6 months in sealed bottle).

Developing with FX 1

I use FX 1 to develop films as follows:

• An initial 30 seconds gentle agitation with a slight twisting action.
• Then 5 seconds agitation (two inversions) every minute.
• Start with a time of 12 minutes and adjust.
• Reduced agitation increases sharpness even more:
• Agitate for the first 30 seconds.
• Agitate every two or three minutes.
• Increase development time by 50%.
• PanF Plus 12 mins Ilford
• FP4 Plus 12 mins Ilford

Tip – Making Potassium iodide 0.001%
the Crawley way!
1. Take 1g iodide and dissolve in 1 Ltr warm water. Stir for 2 mins and let stand for 3 mins. Makes 0.1% solution.
2. Take 100ml of this solution and make up to 1 Ltr with water. Stir 2 for mins and stand for 3 mins. Makes 0.01% solution.
3. Take 100ml of this solution and make up to 1 Ltr with water. Stir 2 mins and stand for 3 mins.
That’s your 0.001% solution.