Riporto integralmente questo articolo di Tim Layton (la sua gallery è visitabile qui: www.timlaytonfineart.com) perchè trovo che rappresenti una sintesi eccellente dell’argomento. I riferimenti sono validi e così pure le sue considerazioni personali (che condivido) sull’approccio alla scelta.
http://www.blackandwhitefineart.net – © Tim Layton – All Rights Reserved
How to Choose A Black and White Film Developer
I was recently doing a bunch of film testing and sorting through which developer I wanted to use. After pausing for a moment I realized that I needed to slow down and think about things clearly before making any decisions. Based on my quandary I decided to write a new article to help other film photographers with some of the high level thoughts they may want to consider when choosing a developer for their own photography. My opinions are my own and I always welcome comments and suggestions from others that are based on experience. I purport that one does not choose a developer or a film alone, rather the combination of the two drive your final decision.
How to Choose a Developer?
The better question to ask might be: what do I expect or want from my developer? What is most important: sharpness, fine grain, shadow detail, consistency, availability, temperature resilient, easy to use, etc. Developers can be generally grouped into two major categories: fine grain (solvent) and sharp (non-solvent) which I cover in the top portion of this article. There is a third category that sort of stands all on its own which is a compensating developer. While technically there are other developers that fit into this category I am going to cover Diafine at the bottom of this article.
For the greatest degree of control you will want to employ a solvent or non-solvent type of developer and for bullet proof black and white negative development nothing comes close to Diafine. With the ability to control so many variables with the solvent and non-solvent developers comes complexities. On the flip side with the benefits of not having to worry about temperature, speed increases in your films and an extremely long use and shelf life also comes at a price. Diafine if used properly will produce normal development time negatives, but as your can guess there also comes a price of lack of control over your contrast and it may produce negatives that you don’t like from a visual perspective.
The fine grain developers are often referred to as solvent developers and sharp developers are called non-solvent. In the end all black and white developers look at the exposed and unexposed areas on your film. The exposed areas trigger the silver halides from their salts and reduce them to metallic silver. The unexposed halides don’t react to the developer and remain unchanged. You might be asking if that is the case then what is all the fuss about? In the end you that may be a very good question to ask yourself again.
Fine Grain Solvent Developers
Fine grain developers are known for creating an etched look in the film emulsion via the silver halide crystals and also having less grain than non-solvent developers. The most notable of solvent developers is definitelyKodak D-76 as it has been called the defacto standard by which all developers are judged. D-76 started back in the 1920’s with movie film makers and has progressed and evolved since then. Fine grain developers like D-76 literally etches the grain into the film and replates some of the dissolved silver back on the grains. Solvent developers are known as low activity developers which in simple terms produces smaller grain and less clumping of the larger groups of grains. That might be very important depending on your style of photography. Other solvent developers would include XTOL or Ilford ID-11.
A solvent developer etches the silver halide crystals in the emulsion, giving finer silver halide grains to work on and providing a source of silver ions to compete with the chemically reduced silver particles, which are coarser. Developers like D-76 facilitates the silver density build up by the physical action of the dissolved silver replating itself as discussed above in addition to the chemical action of the developer. Non-solvent developers has very minimal solvent action as you may have guessed.
I have used D-76 at a +1 dilution to get an increase in sharpness with only a very minimal increase in grain in my 120 medium format roll films. Since I can’t develop individual frames on a roll film I feel that D-76 is best suited to cover the wide range of exposures that may exist on a single roll. D-76 is known as a great general purpose developer for maximum shadow detail. Depending on your style of photography that might be very important to you. I always use my developers as one shots for maximum consistency. By diluting it also gives me longer and more manageable development times for my N- and N+ times.
Many people claim that XTOL is sharper and you can get bigger enlargements because of less grain over D-76. I recently ran some informal tests by photographing the same scene with the same film and developing one film in D-76 +1 and the other in XTOL +1. Some images I did not notice much difference other than slight tonality variations. On other frames I noticed a significant difference in sharpness. On those specific negative the sharpness difference was astounding. I would suggest that you run your own tests to determine how the two developers behave in your environment and with your style of photography.
One advantage that people like about XTOL is that it can be mixed at room temperature as opposed to 121F for D-76 but this is a non issue for me personally. I also don’t like having to buy it in a 5 liter bag, meaning you are forced to mix up 5 liters (1.32 gallons) at the time of mixing. I have never seen the 1 liter bags available anywhere. I purchased two amber glass storage jugs (1 gal and 1/2 gal) and mix up the entire bag as you should and then store it as stock solution as directed. It does have a 6 month shelf life if stored properly so it just depends on what you feel like messing with. Based on my results use XTOL diluted when sharpness is the most important and D-76 diluted when I have a wide range of contrast on a single roll. I push Tri-X up to 3200 in D-76 stock for best results.
Kodak Overview of D-76
KODAK PROFESSIONAL D-76 Developer provides full emulsion speed and excellent shadow detail with normal contrast, and produces fine grain with a variety of continuous-tone black-and-white films. For greater sharpness, but with a slight increase in graininess, you can use a 1:1 dilution of this developer. It yields a long density range, and its development latitude allows push processing with relatively low fog. I always use D-76 diluted except when I am pushing Tri-X. If you are going to use D-76 on tabular grain films I would highly recommend diluting D-76.
Non-Solvent Developers
High acutance (sharp) or non-solvent developers are generally described as surface type developers as opposed to a physical developer like a fine grain/solvent developer. Probably the most notable non-solvent developer is HC110. Others would include FX-1, FX-2, and PMK(Pyro). I would consider HC110 being an industry standard and the others are more of a specialty type developer. I use HC-110 for my large format sheet film development because of the degree of control I have over my contrast and I don’t have to worry about grain or sharpness.
Non-solvent developers are known to produce a coarser grain structure but the image “appears” sharper. While you may have more grain the acutance masks it. Here comes the tricky part. Some developers can belong to both categories depending on how they are diluted and used. For example undiluted D-76 (stock) is a solvent fine grain developer as discussed above. However, if it is diluted to 1+3 it becomes a non-solvent high acutance developer. I would definitely consider XTOL 1+3 in this category as well and probably could be considered to perform like the best non-solvement developer but also carry the positive charactertistics of finer grain (solvent) developers.
Non-solvent developers do produce prints with more grain as indicated above because there is not a lot of solvent to dissolve the edge of the grain. The grain clumps together a little more than solvent type developers giving an appearance of more grain. And, because of the fine detail (micro-contrast) ability of non-solvent developers it gives the visual appearance of more grain as well.
Kodak Features and Benefits of HC110
Developer Selection and Your Prints
The only reason you are exposing film is because you want to make a print or I guess for some people on online or digital image. With this in mind it is important to think about your developer in relation to your final print. In general, non-solvent developers will produce a print that looks very sharp, but you guessed it, there is a price to pay. The price is increased grain and a little less smoothness in tonal gradation. That may or may not meet your technical or artistic requirements.
Solvent developers produce mid-tones that have a smoother gradation and a finer grain. If you create images that use out of focus areas with a small aperture (shallow depth of field) like closeups of flowers or large areas such as a sky with little texture, then you need to keep in mind that non-solvent developers will produce much more grain than its counterpart.
On the other hand if your scene has a lot of detail and you have a lot of depth of field such as landscape photography then you will find that you probably like the results of a non-solvent developer better. Many large format sheet film photographers use HC110 as their developer. One thing you can do is to shoot two exposures of the exact same image and develop with two different developers and form your own opinions.
Does Film Format Matter?
Do you think film format (i.e., 35mm, 120, large format sheet film) matters when it comes to selecting a developer? Of course it does or I would have no reason to write this section!
When using 35mm or 120 medium format your main goal as a photographer is to create a negative that will print sharp, have fine/limited grain and have good tonal range/gradation. For me the answer is D-76 diluted at +1 or XTOL 1+1 depending on the scene and vision I have for the print. With large format sheet film the issue of sharpness and grain are not of concern and so tonal gradation is the key.
Roll film (small and medium format) should be given the least amount of exposure that will provide you with the desired amount of shadow detail. In other words the negative should be thin as compared to a large format negative. If your small or medium format negative is dense/thick then it will have more grain and less sharpness as you enlarge it. There is always a catch. When you take the strategy of minimal exposure for shadow detail you pay a price for poorer shadow gradation. The only way to address this is during the printing process with traditional darkroom techniques like burning and dodging. If you are scanning your negatives then the same techniques that are used in the darkroom can be handled in Photoshop.
The problem that you run into with roll film whether it is a big beautiful 6×9 medium format negative or its baby brother the 35mm negative you must select a developer with a big margin for a wide variety of different exposures. You could have anything from very low contrast scenes to ultra high contrast scenarios that need to be developed all on the same roll with one developer. There is always a price to pay for that convenience! The best types of developers for roll film are fine grain (solvent), high definition and the dilution of fine grain developers as mentioned above. D-76 Stock +1 does not do a great job when it comes to excellent sharpness with minimal grain and ultra smooth tonal gradation. However, before you toss in the towel on D-76 you should know it is literally unbeatable when it comes to producing printable negatives from a wide range of lighting situations and contrast. You may have figured out if you are a large format photographer and have the ability to develop each individual sheet you probably won’t be using D-76. If you are a hybrid photographer that also scans your negatives then I would tell you that a thinner negative will scan better and produce better results so D-76 or XTOL diluted should perform very well.
As mentioned above large format photographers focus on tonal gradation because grain and sharpness is much less of an issue because of the size of the film. Since you have the luxury of developing each sheet of film individually you can control the contrast in your negative by development times. This is why you will see large format photographers leaning towards slower developers so they have enough room to control the times for development times (N-1, N-2, N+1, N+2). HC110 is probably the defacto standard for modern day large format photographers because of its contrast control, storage life, ease of use and dilution options. It was good enough for Ansel Adams so surely it has to be good enough for me. You can still find famous large format photographers like John Sexton using D-76 as their developer. If it is good enough for John it is certainly good enough for me. The man is a legend to say the least.
Your Style of Photography
Your style of photography can absolutely impact your choice in developers. I do a lot of landscape photography and I am constantly challenged by the dynamic range of light in my scenes whether it be very high or very low contrast. You will find a lot of experienced photographers using PMK or Rodinal for high contrast scenes because you can still print those hard to print highlights. Of the two developers I would select PMK for high contrast scenes based on cost and availability but the chemicals are very harsh and nasty. However, for very high contrast scenes I would simply rely on my HC110 process and for 120 roll film I would probably use Diafine and call it a day. For low contrast scenes a stronger developer like D-76 will be a great choice.
For roll film users that have to deal with a mix of various contrasts on one roll of film a compensating developer like D-76 Stock+1 should produce very good results. Remember your goal is to make the best negative you can and ensure that it is printable or for some scan well and facilitate the best manipulation in the digital darkroom.
Modern variable contrast papers and filters can make up a lot of ground when you are slightly off on your negatives. If you are scanning your negatives then Photoshop will enable you to compensate for all sorts of exposure and development blunders. You just don’t want to box yourself into a corner with shadow detail because remember you develop for your highlights first and then work on your shadow detail with your variable contrast filters. Also keep in mind that D-76 is the developer that all other developers are more or less measured by so it is readily available and you will find it listed on just about every film specification sheet.
If you are running and gunning with a hand-held camera and have no idea what you are going to run across then I would suggest using the defacto standard for press photography which is Tri-X and D-76 Stock+1.
Other Facts to Consider
Even in photography and art there is a business angle at some point to consider. In regards to developers no film manufacturer will make a black and white film that won’t develop well in the worlds most popular developer. Can you guess which one it is? If you said D-76 you were right. The big name film manufacturers such as Kodak and Ilford won’t likely produce a film that won’t perform well in D-76 and I would go out on a limb and just about say the same thing for HC110. This is something that you need to consider when thinking about the long term viability of your business, processes and procedures.
Ask Yourself Some Questions
I would suggest asking yourself the following questions when considering a black and white film developer:
- What is your style or genre of photography? A portrait photographer will probably use a different developer (e.g. D-76, XTOL) than a landscape photographer (e.g. HC110).
- Do you want to use an industry standard to reduce risk of long-term elimination of your developer?
- What are your requirements or limitations for storage or shelf life?
- How big do you need to make your enlargements? Based on your format (e.g. 35mm, 120, 4×5, 8×10, etc) you should consider how big you want to make your enlargements and weigh out the pros and cons of solvent and non-solvent developers.
- What format of film do you use (e.g., 35mm, 120 Medium Format, Large Format)? The larger the source negative the less you have to worry about issues like grain and sharpness and you are more focused on tonal gradation and shadow detail. If you are a large format photographer you have the luxury of making choices per exposures vs. a roll film photographer may have to deal with wide variances on a single roll.
In the end I would say that it is more import to properly test and document your normal, contracted and expanded development processes with a single developer as opposed to trying to use too many developers. Some of the greatest photographs of all time were taken with extremely simple cameras and lenses that we would not look twice at today and developed in small closets. If you are a hybrid photographer using film as your medium and scanning your work, the issue of grain is no longer a problem because of tools like Lightroom, Aperture and Photoshop. You can literally eliminate excessive grain from a scan in the matter of seconds and dial in whatever degree of sharpness and contrast that you feel is appropriate.
The point I am trying to make is this. A person can get carried away with all of the technical details and lose sight of the art and purpose of their work. My best advice is to pick one or two standard developers and use them day in and day out until you know exactly how they will perform with your film and style of photography. Only use a couple different films for the majority of your work and narrow your variables and opportunities for problems. Too many variables in your photography can lead to the inability to make proper adjustments and I would say managing a lot of variables is typically a waste of your time.
For my photography I have standardized on T-Max 100 and Tri-X for my workhorse films. For medium format I use D-76 and XTOL and for large format I use HC-110.
Tabular grain (T-grain) films such as T-Max and Delta 100 need to be fixed longer than classic films and also washed very well. T-grain films dope the silver halide so that it forms “tabular” crystals. The T-grain is a little flatter than conventional grain and is thought to be more efficient at capturing light. I think it presents more surface area to the light for a given amount of sliver. T-grain films typically have a thinner layer of emulsion as well.
Special Scenarios
There will always be special scenarios that will crop up from time to time depending on your style of photography. For example, I don’t do a ton of night photography but when I do I use Delta 3200 with Microphen or I push Tri-X to EI 3200 and develop in D-76 stock. I can produce a usable EI from 1600 to 25,000 with the Ilford films that is compatible with any modern DSLR and Photoshop. Keep in mind that roll film can include 6×12 and 6×17 pano backs on large format cameras too. For serious large format night photography Tri-X 320 Professional in HC110 or D-76 is difficult to beat.
Kodak Quick Reference Chart
Mark Olwick read this article and sent me a link to the Kodak developer quick reference chart. The chart is very subjective and looking at it without discussing a number of other variables is likely meaningless. In other words there is no way I could make any type of comment or observation about any of the developers based on this chart alone. If you haven’t checked out Mark’s photography you should definitely do so.
And Then There was Diafine
I’ve written a detailed article about Diafine so you may want to read that first before reading the rest of this section unless you already have a solid understanding of this developer. I’ve also written instructions on how to develop your roll and sheet films that you may want to reference too.
What can I say about Diafine? It is like black and white magic soup that lasts forever. My current batch of Diafine is over a year old with a suspected life of 2 to 3 years. Not bad for $12!
There is no need to repeat the technical details and how Diafine works because I’ve already covered that in the Diafine article. I would sum Diafine up as follows. If you are new to black and white film development no matter your format (i.e., 35mm, 120 medium format, large format sheets) then Diafine is absolutely without a doubt the place to start. You will produce very good scannable and printable negatives from your very first batch and be able to do that again and again and again. Focus on your photography and then over time consider traditional developers if you are not getting what you need out of Diafine.
I have used Diafine in scenarios where the contrast of the scene is very high like 8 or more stops of light. There could be deep shadows on the edge of a landscape with bright sun beating down on the side of a mountain and there is 10 stops difference in light. While there are processes that could be done with normal developers Diafine is a perfect answer for this type of challenge in many cases. It doesn’t have to be landscapes, maybe it is indoors at a concert with bright lights and a dark stage. If I am shooting roll film and have a wide variance in contrast on my negatives then Diafine is a very good solution for this as well. I can shoot the exposures at different EI ratings on the same roll of film and develop in Diafine for excellent results. You could never do that with a normal developer.
If you employ a normal developer and do it right then there is extensive and I mean extensive testing that is required to properly employ it whether you use visual or scientific methods. It is a major investment of your time to do it right and there are no shortcuts. Diafine eliminates all of this and produces good quality negatives with certain films time and again. There is probably no better combination than Tri-X and Diafine and if you want to try Diafine that is where I would suggest you start. T-grain films don’t typically perform as well as conventional films so you may want to keep that in mind. Tabular films would include standards like Kodak Tmax 100, Tmax 400, P-3200, Delta 100/400/3200. Conventional films would include Ilford Pan F+, FP4+, HP5+, Kodak Tri-X, Plus-X and Fuji Neopan films. If you follow the Diafine forums you will find people talking highly about Tri-X, Fuji Neopan films and eastern European films like Efke and Fomapan. I recently tested Fompan 100 large format sheet films in Diafine and really liked it.
Final Summary
In the end you will likely end up with a normal developer and Diafine if you are an advanced black and white photographer. Developers are simply tools that help get you to your final goal whether that be a scan, darkroom print or digital inkjet print. If you are unable to properly test and plot your film characteristics then for normal developers I would say to rate your film at half the box speed and for normal development times just cut the times a little based on what the manufacturer says. This will get you most of the way there and if you want to really dial in your photography you would need to conduct a series of film speed and development tests to be used with the zone system. For many people the zone system is not necessary. For Diafine just shoot Tri-X and rate the film per the Diafine spec sheet and you will get great results.
References
There is no better reference on this topic than the Ansel Adam classic “The Negative” and “The Film Developing Cookbook” by Steve Anchell. Everything that I have learned has started with these books and the rest is just based on a personal investment of time and experience and help from other photographers that are kind enough to share their knowledge. I highly recommend any serious photographer own both of these books and continue to read and reread over time.
This article first appeared on my analog film photography blog at http://www.blackandwhitefineart.net – © Tim Layton – All Rights Reserved
Tim Layton
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