Processing 35mm and 120 film

Black and white film processing is so easy that we are constantly amazed anyone sends it out. You don't need a darkroom to develop film: a changing bag will do, as seen in the free How do I...? module on choosing a developing tank. There are also free modules on how to load 35mm or 120 film onto reels for development, and even on how to convert the smallest room in the house to a darkroom. The rest of the equipment you need is listed below.

The most important thing is not to be intimidated. There are countless gurus, especially on the internet, and there is so much conflicting advice that it is easy to conclude that it must be very difficult indeed. In fact, if you think about it, the exact opposite must be true. Almost all the combinations touted by gurus for film and developer and film speed and time and processing regime deliver acceptable or even good results. Obviously, therefore, there is a lot of flexibility in the process. The chances are that your very first attempt will be at least as good as anything an expensive pro lab can do, and after that, you can only get better. There is a short, free module on why you should ignore gurus.

Door, Loches

 

A refusal to be intimidated can include a refusal to be intimidated into doing your own processing. If you do not want to do your own processing, we firmly believe that there is no better film than Ilford XP2 Super, which can be run through standard commercial minilab chemicals. Gurus and photo-snobs often dismiss XP2 as unsuitable for 'real' photographers, but we unkindly suspect that often, this is because they feel threatened by it: many cannot achieve the same quality as XP2, regardless of what obscure and faddish films and developers they use.

A more legitimate concern is that most mini-labs stabilize the film instead of water-washing it, which may limit its life to a few decades (though we are still printing XP1 from the 1980s). Roger shot this with a Voigtländer Bessa-R2; Frances printed it on Ilford Multigrade Warmtone.

 

Even if you buy the best available new equipment -- tank, thermometer, graduates -- you will have considerable difficulty in spending £100$200/150 euros, and it should last you the rest of your life. You may well be able to find second-hand equipment, or there may even be someone at your camera club who has gone over to digital and will give you the equipment you need. After that, although processing chemicals are surprisingly expensive, each bottle or package processes quite a lot of film and you will save a fortune as compared with a custom lab.

And it's quick. Depending on the film and chemicals chosen, it usually takes under half an hour to process a film (or batch of films) from start to finish: see 'The sequence' below.

developing outfit

 

The equipment

 

You need a developing tank with one or more reels; a thermometer; (coming soon) a timer; and one or more measuring jugs or graduates. It's easier if you have more than one graduate in each size, as it allows you to reserve one for each chemical bath, but it's not essential. Likewise, although a stop-clock is easier, a watch or clock is fine. If you don't have a room, cellar or large cupboard you can black out completely, you will also need a changing bag (see loading 35mm into a tank). Ideally, of course, you want a darkroom (free module) -- but you certainly don't need it at first.

 

Film developing outfit

 

Tank (with spiral inside); thermometer; graduate or measuring jug; some means of timing. This is all you need in the way of equipment. We use separate graduates for developer and fixer, to avoid cross-contamination, but if you wash your graduates carefully, one is enough. There's more about jugs and graduates later in the module.

Clear plastic graduates -- this is from Paterson -- bounce better than glass and accept marker pens quite well, for emphasizing commonly-used measures. You can see that this one has been marked with 16 and 20 UK fluid ounces; the '4' marking is less clear, but 4+16 is an easy way to make up developer or fixer at 1+4. The US fluid ounces are marked for 2, 8 and 10 fluid ounces. You'll see why, below.

 

 

The chemicals

You need a developer, that brings up the latent image on the film, and a fixer, to remove the unexposed and undeveloped silver.

A 'stop bath' between the developer and the fixer is optional. This a very weak acid solution, usually acetic (effectively very dilute vinegar) or citric (as found in citrus fruits, hence the name), that stops the action of the alkaline developer and prolongs the life of the acidic fixer. The other optional chemical is wetting agent for use just after the final wash, as described below.

Developer and fixer

Most people buy their developer in litre bottles, but 5-litre containers like this are cheaper per litre and the concentrate keeps for a very long time. Ilfotec DD-X is quite an expensive developer but 1 litre of concentrate should develop at least 10 films. The concentrate also keeps extraordinarily well without oxidizing, unlike some other developers.

 

developer & fixer

 

Ignore all that you read about 'magic bullet' developers, alkaline fixers and other vapourings of self-proclaimed gurus. Yes, most of them probably work, and some people can get excellent results from them, but ask yourself a simple question. If they really are superior, why are they not the mainstream? There are paid modules on choosing developers and development technique. Both go into more detail than this module, but you will find all that the beginner needs, right here.

The only other thing you need is water, for washing. And you don't need much of that.

elephant grass

boat on dive

overhanging tree

Sentier des Lavoirs, Moncontour

Roger shot these one autumn morning in 2007, in the course of a walk that took about three-quarters of an hour. Half an hour after he was back, the negatives were hanging up to dry. The camera was an old East German Pentacon Six SLR with 80/2.8 Biotar; film was Ilford HP5 Plus, rated at the manufacturers' box speed (ISO 400) and developed in Ilford DD-X diluted 1+4. Later, Frances made the prints on Ilford Multigrade Warmtone.

The sequence

The basic sequence is developer (5 to 15 minutes -- anything longer is likely to be faddish and of dubious value, at least to the beginner); optional short stop or wash (30 seconds to 2 minutes); fixing (typically 2 to 5 minutes); washing (maybe 5 minutes if done as described below); and drying, during which time you just leave the film to its own devices. Add these together and the actual working time (i.e. not counting drying) is 12 to 27 minutes.

The important things are to fill and empty the tank as smoothly and quickly as possible and to be as consistent as possible. The shorter the processing step, the more important are filling and emptying, as the percentage error grows greater.

For consistency, always start and stop timing from the same stage: either from starting to fill the tank, or when it is full. Allow 10-15 seconds draining time at the end of each stage: the chemicals will continue to act unabated until the next bath is poured in.

Filling a Paterson tank

The wide mouth means that you can pretty much just dump the chemicals in: with a stainless tank, you need a steadier hand because the mouth on the lid is smaller.

filling paterson tank

 

The other important thing for consistency is agitation. Once the tank is fill of developer, bang it smartly on the table a couple of times to dislodge any air bubbles, and agitate continuously for the first 30 seconds of development. This can be by inversion or by 'twiddling' (see illustration below). Inversions are normally carried out at the rate of one per second or so for one cycle, from upright, to upside down, to upright again. If you take 3/4 second or a second and a half, don't worry, as long as you're consistent.

dev tank

 

After the first 30 seconds, opinion is divided on whether it is better to agitate for 5 seconds every 30 (typically 4-6 inversions) or 10 seconds every minute (typically 8-12 inversions). It doesn't matter much, as long as you choose one or the other, and stick to it. Actually, it won't take that much difference if you swap between the two: certainly, less variation than you would expect between two pro labs.

Twiddling

Paterson plastic tanks (and some others) have a little rod that can be jammed into the middle of the developing spool core and used to 'twiddle' the film instead of inverting. The important thing is to reverse the direction of flow by twisting first clockwise, then anticlockwise. Otherwise you may get streaking where the developer flows steadily instead of being agitated randomly. Times for twiddling are as for inversions.

Are the chemicals dangerous?

You wouldn't want to drink any of them, before or after they are used, but the simple truth is that as prepared for use, the worst you are normally risking (and only in a tiny number of cases) is contact dermatitis from the developer. Avoid dabbling your fingers in it, and wash off any splashes reasonably smartly, and the risks are negligible. In fact they are pretty tiny even if you don't take such precautions: countless photographers like to get their fingers wet, and only a tiny percentage get dermatitis.

As for disposal after use, there are two schools of thought. One is that by the time the chemicals have been poured down the drain and been diluted by the normal volumes of other waste water, they are completely undetectable by the time they reach the waste-water treatment plant. Fairly obviously, if they are undetectable, the biohazard is not great. Most waste-water authorities take the view that for the small amounts used in amateur darkrooms, down the drain is not a problem.

The other school says that because some working-strength chemicals can be toxic if undiluted, they must be disposed of as toxic waste. This is a somewhat absolutist view, as evidenced by the first school of thought. A few waste water authorities do however prohibit the disposal of some (not all) black and white photographic chemicals by pouring them down the drain: fixer is the only common example. Some arrange periodical free collections; others require you to use professional waste disposal services. A favoured way to get rid of 'spent' (exhausted) fixer is to take it to your nearest minilab. Most will dispose of it for nothing, not least because they can recover some of the silver dissolved in it.

Jugs graduates and toxicity

Our photographic forebears used the same jugs in the kitchen and the darkroom, and very few died of it, but we heartily recommend keeping separate sets. In the pictures below, the two glass jugs are indeed from the kitchen, and therefore never used in the darkroom, but the plastic jug is from the darkroom: you can just see the writing on the other side (it says 'fix'). Multiple measuring vessels -- one jug of developer and another of fixer -- are quicker, easier and safer (less risk of cross-contamination) than re-using the same jug, but of course you can use your most precise jug or graduate for developer and another for fixer.

dev jugs

 

Kitchen jugs and graduates

The taller the jug or graduate in proportion to its volume, the easier it is to read the level of the contents accurately and repeatably; this is why graduates such as the Paterson set on the right are tall and thin. The red-label jug on the left would be barely tolerable; the blue-label jug is adequate; the tall plastic jug is fine for chemicals used at normal dilutions, up to about 1+9. The greater the dilution, the greater the scope for error, so we do not recommend going above 1+9 at first.

 

The most useful measures are 600ml and 1200ml (as they allow 500 ml and 1 litre with a reasonable space above). Volumes in the 10ml-100ml range are easiest measured with a 100ml graduate; volumes under 10 ml. are best measured with a pipette or very small graduate. Some use graduated syringes but they can be hard to clean.

Mixing the chemicals

Traditional photographic chemicals were sold as powders, to be mixed with water. Liquid concentrates are more expensive -- you are paying to ship water, and some of the ingredients are more expensive for a variety of reasons -- but they are a lot more convenient to mix up, and they remove the risk of dust inhalation (still a very slight risk unless you are careless) during mixing.

 

A counsel of perfection is to use distilled or de-ionized water for mixing, but unless your tap water is very nasty indeed, there is unlikely to be any need. We use water drained from our darkroom dehumidifier (see our darkrooms) and the Victorians commonly used rainwater instead of well-water.

Dehumidifier

Water from a dehumidifier in a room that is normally lighted may have algae in it -- the receiver will feel slimy -- but a darkroom dehumidifier should not suffer from this problem: the algae require light to live and multiply.

The ratios for mixing are given on the bottle. Typical ratios are the 1+4 of the Ilford DD-X developer and Hypam fixer we use, and 1+7 or 1+9 for some other developers. Calculating the volumes needed is easy. Let us say you want to make up 500 ml at 1+4. Well, 1+4 = 5, so divide 5 into 500 and if you use 100ml of developer and 400ml of water you will have 500 ml at 1+4. Going to 1+9 is equally easy: 1+9 = 10, and 500 divided by 10 is 50 so 50ml + 450ml = 500 ml. It is often easier to mix a little more than you need, and discard the surplus, rather than try to measure (for example) 87.5ml of concentrate.

 

We do not recommend, at least at first, trying super-concentrated developers with dilutions such as 1+39 or above: 500ml at 1+39, for example, is 12.5ml concentrate made up to 500ml. In fact, we don't recommend them even when you have plenty of practice and a pipette. We wouldn't suggest that you should never use them -- some people get superb results with them -- but for all too many photographers, arcane developers are a substitute for creativity.

Ilford Hypam label

This is enlarged from the picture above. You can see that the fixer is diluted 1+4 for film; that the recommended fixing time is 2-5 minutes at 20C/68F; and that 1 litre of made-up fix will process 24 films: 135-36 (36 exposure 35mm) is roughly equal in area to one 120 film or one sheet of 8x10 inch film.

The same sort of fixer can be used at either 1+4 or 1+9 for fixing paper. Resin-coated (RC) paper fixes twice as fast as fibre-base (FB) and twice as many sheets can be run through 1 litre (80 instead of 40).

It is NOT a good idea to use the same batch of diluted fixer for both film and paper as the build-up of silver in the fixer renders it unsuitable for fixing paper: you may get stains, weeks, months or years later.

fix dilution

 

Many graduates are marked in both metric and fluid ounces, and many developing tanks are either 8 oz or 16 oz (American half pint and pint -- a full Imperial pint is of course 20 oz), so even if you normally use the metric system, there are times when ounces are worth considering. American and Imperial ounces are slighty different, but as long as you stick to one or the other for mixing, it won't matter.

At this point, obviously 1+7 is dead easy: 1 oz of concentrate plus 7 oz of water gives you 8 oz (about 225 ml) of working solution, or 2+14 = 16. Depending on the dilution and the size of the tank, we switch freely between ounces and litres, mixing (for example) 16 oz of developer and 500 ml of fixer. This is why the graduate in the 'basic equipment' picture above has 4, 16 and 20 oz. highlighted.

One-shot and reusable chemicals

Developers may be re-used, in which case you need to increase development times for each film after the first in order to compensate for reduced developer activity, or they can be used 'one-shot' where they are thrown out after use. For consistency and full film speed, we unreservedly recommend one-shot development. All manufacturers give appropriate instructions for appropriate use (one-shot, re-used or both) for their own developers.

sepia gates

 

Short stop may be re-used. Many incorporate an indicator dye that goes from yellow to purple when the stop is no longer acidic. We normally use short stops one-shot, making them up with a dash of 80% acetic acid in water.

Fixers can and should be re-used, as noted below. Wetting agent costs so little that there is no sense in keeping it for more than one session, though we cheerfully use the same 450ml of diluted wetting solution for all the films we process in one day.

 

Gates, Belgium

Peel-apart Polaroid films provide the ultimate example of one-shot development, and also illustrate how very little developer is needed actually to develop a film. The vast majority of the developer that you pour into the tank is there for one reason only: to wet the film as rapidly and evenly as possible.

With a very few exceptions, mostly of developers that oxidize very rapidly indeed, you do not need to worry about whether there will be enough developer to process your film: a tank-full, no matter how small the tank, will be enough.

You need enough developer to cover the film, and no more. Overfill the tank, so there is no air-space at the top, and agitation will be a lot less thorough: think of inverting full and half-full bottles of orange juice. Roger used our Toho FC45 here with our 120/6.8 Angulon.

Time and temperature

Many years ago, films were developed by inspection under a red light. This would fog almost all modern films, so the normal approach is to develop for a fixed time at a fixed temperature.

Most manufacturers give developing times for two standard temperatures, 20C (68F) and 24C (75F). These are pure convention, representing temperatures that are easy to achieve for most people under most climatic conditions. Before the 1960s, many people used 65F (18C) as the standard, because central heating was less common, and there are 'tropical' developers designed for use up to around 30C, 86F. These represent realistic limits, because developing times get very long below about 65F/18C, and beyond 30C/86F you run the risk of very short developing times. Also, with older emulsions, high temperatures led to the the risk of excessive swelling and softening and mechanical damage or reticulation, the latter a sort of wrinkling or eczema of the gelatine that you get when you go from a warm solution to a cooler one, or from one concentration of warm chemicals to another.

Mix the chemicals as close to the right temperature as you can (use a pre-mixed jug of water within a degree or two of the right temperature), then either stand them in a water bath until they reach the right temperature (warm water or ice water, depending on season) or adjust the time for the actual temperature you have. Although the relationship between time and temperature is not strictly linear, you can treat it as if it were. Thus, if the development time at 20C/68F is 9 minutes, while at 24C/75F it is 6 minutes, you can safely give 7½ minutes at 22C/72F -- and the fact that 22C is 71.6F, while we used 72F, is indicative of the level of precision needed.

Temperatures after the development stage (including washing) should be close to the development temperature, but variations of a few degrees are unlikely to matter. Thus, if you develop at 24C/75F, it won't matter if the short stop and fixer are 22C/72F and the wash is at 20C/68F.

Paterson stop clock

Most good stop clocks have three buttons: start, stop and fly-back (to zero). Push the start button down (green here) and the stop button (red here) pops up. Push the stop button and the start button pops up. A few clocks have a single up/down, start/stop lever instead of separate start/stop buttons.

It is perfectly possible to use a watch, wall-clock or stopwatch for timing, but a stop-clock makes it easier. They are not hard to find second-hand but they do gum up with age. We prefer spring-driven clocks to battery-powered because it is always faster to wind a clock than to find and fit a new battery.

patersonstop clock

 

Development times

Developing times are the critical ones, and if at all possible, it is very wise to stick to the identical time, temperature and agitation regime for maximum consistency. Having said this, don't worry about time/temperature adjustments as outlined above, at least across the 20-24C/68-75F range. It is by no means certain that the differences are separable from other variables in the photographic process, though there are always people who will tell you that they are vital. When there are any differences, they are due to the way that two (rarely more) developing agents in the solution are differentially affected by temperature: you may get a tiny bit more or less contrast.

undeveloped

Undeveloped film

Initially, the film is blank (and would be written off if exposed to light like this).

½ developed

Early stages of development

At first, a very faint image begins to appear. This is the second roll written off to shoot this sequence!

¾ developed

Substantial development

You can see that there is much more contrast now, and the edge markings are increasingly clear.

An interesting exercise is to re-measure the temperature of the developer after pouring it out of the tank. It is quite possible that it will be a degree or two cooler (in a cool room, where the tank is below the processing temperature) or a degree or two warmer (in a warm room, where the tank is above processing temperature). It is easy enough to allow for this. We have a thermometer in the darkroom to show the ambient temperature, and if it is 18F/65C when we're processing at 20F/68C we'll cheerfully add on 30 seconds to (say) an 8-minute dev time because we know that the dev will come out at maybe 19 degrees. Alternatively we'll put the dev in at 21C/70F and use the standard time: this is sometimes known as the 'fly-by' or 'controlled drift' technique.

You meet people who swear that developing times are critical to within 5 seconds or less, but an accuracy of +/-15 seconds/quarter minute is normally adequate for development times over about 5 minutes; dev times of 5 minutes or below are risky because of the time it takes to fill and empty the tank and the danger of uneven development. Use a lower temperature or a more dilute developer to lengthen the time.

Manufacturers times and personal times

Manufacturers' developing times are invariably the best starting point: why else would they give them? After all, they want you to get the best possible results from their materials.

This is not the same as saying that these are invariably the best times for you. In fact, Ilford used to give a range of developing times. They stopped doing this because those who understood what they were doing would vary them anyway, while those who were just beginning would almost invariably choose a mid-way point between the two.

It is however very important to watch out for gurus when you are talking about development times. There is a widespread belief that manufacturers maliciously give development times that are too long. Well, they may be too long for some people; but for others, they will be too short, and if you shorten them still further in accordance with the maunderings of the gurus, you'll get really awful results.

In the days when Ilford gave a range, we always started out at the top of the range, because that gave us the best results for our subjects, equipment, technique and enlargers. Nowadays, our starting point is normally 10 per cent above the manufacturer's recommendation. The free modules on subject brightness range and density may help explain some of this. Or they may confuse the beginner, in which case ignore them and go back to them when you feel the need.

Waterfall, Julian Alps

With uncalibrated monitors it is impossible to show the full range of subtlety of a black and white print, but there is texture just about everywhere on this one, except deep in the cave from which the waterfall issues. Even then, there is detail on the negative that we chose not to print. There can be a lot of difference between printing for maximum drama, and printing for maximum tonal range. 

And how did we expose and develop it? By following the manufacturers instructions, plus about 10% extra development. To be fair, we knew that the developer chosen (Ilford DD-X) gave extra film speed with the film chosen (Ilford HP5 Plus), so we were effectively giving about 2/3 stop more exposure than was strictly needed. Roger used a Nikon F with 200/3 Vivitar Series 1 lens and Soviet-era 2.8x orange filter.

slovenia waterfall

 

If you are dealing with a film/developer combination for which you have no details from either the film manufacturer or the developer manufacturer, the massive development chartis a great starting point but it is not Gospel: many people find that they need to depart very widely from it for the best results. For example, we used it as a basic reference when we developed Efke IR820C in Ilford DD-X but we soon found that the 7.5 minutes quoted at the time we checked (the chart is constantly updated) was far too short: 12-14 minutes suited us much better.

stop bath

 

Short stop times

These are not outstandingly critical. Anything from 15 seconds to 2 minutes is about right: we normally use 1 minute. Others use a plain water rinse (again, 15 seconds to 2 minutes) and some go straight to the fixer.

 

Indicator short stop

The short stop in the graduate on the left is freshly mixed, and yellow. It will stay that colour until it loses its acidity and turns pink or purple as on the right.

Fix times

Most modern fixers are 'rapid' and will fix a film is a very few minutes: they are based on ammonium thiosulphate rather than the old 'hypo'. You can find both hardening and non-hardening fixers. The former, as the name suggests, harden the film. This may sound like a good idea but there is absolutely no need for it with modern films (except perhaps a few Eastern European emulsions) and hardening greatly lengthens washing times, so (in company with Ilford) we heartily recommend that you do not use them. Use the fixer manufacturer's recommendation or test the fixer yourself, as follows.

On the torn-off leader of a 35mm film (or clipped end of 120, though it is more difficult cutting 120 in the dark), place one drop of fixer. Let it act for 10-20 seconds. Then put the film in the body of the fixer, making sure it is submerged. Start timing. The initial spot will clear first. Then the area around it will clear. When you can no longer see the spot, that is the 'clearing time'.

hypo test 1

 

Fixer clearing test

Although this is shown being done in a tray, for ease of photography, you would normally do it in the graduate full of fixer, mixed ready for use.

The reason for the spot is that it makes it much easier to see when the film is, indeed, as clear as it is going to get.

hypo test 2

 

Fix for at least twice the clearing time. Fixing for more than this will rarely do any good, though equally, it will do no harm unless fixing is very prolonged: typically, 15x the clearing time or more. In other words, if the spot clears in 20 seconds, the minimum fixing time is 40 seconds; you can give 60 seconds for good measure; and beyond about 300 seconds (5 minutes) there is a slight but increasing risk of the fixer attacking the image as well.

If you re-use the fixer (which makes eminent sense, both economically and environmentally), this approach has the additional advantage of functioning as an exhaustion check. When the clearing time in the used fixer is twice the time for fresh fixer, it's time to mix new. This has a safety margin built in: if you're short of fixer you can go to 3x, but fixing times can get inconveniently long, and 3x clearing time really is as far as you want to go in any case, because fixer with any higher silver concentration may not fix adequately.

film developed

 

Fully developed but unfixed film (left) and fixed film (right)

These are the last two shots in the sequence started above. In the fully developed but unfixed film, the creamy silver halide is still in the emulsion. Not only does it block the light in the clear areas: it would also darken steadily as it was exposed to more light.

The fixer removes the silver halide and renders the clear areas clear. All that has to be done after this is washing and drying.

fixed film

Washing

Assuming you have used a non-hardening fixer, as recommended, you can wash film to ANSI archival standards with just three changes of water, the so-called 'Ilford sequence'. Fill the tank; invert five times; drain; refill; invert ten times; drain; refill; invert 20 times. Contrary to what you may read elsewhere, there is no need to wait 5 minutes between washes, at least if you use modern Ilford materials: every test carried out by Ilford and others with Ilford film and chemicals (and indeed with many others) indicates adequate washing without the 5 minute rest, which dates back to Kodak recommendations in the 1930s or 40s.

This wash sequence is so quick and easy that many people refuse to believe it, and 'gold plate' the sequence with extra washes. In fact, we do, but for other reasons. We live in a very hard water area. Hard water washes better and faster than distilled (believe it or not) but it can also leave drying marks. We therefore do the Ilford sequence, then fill the tank with distilled water for another 10-20 inversions. Finally, the film is transferred to a weak solution of wetting agent in distilled water, and left for at least a minute. After that it is hung up to dry with a weight on the bottom: a clothes-peg will do, but a weighted processing clip is even better.

Continuous washing

Where water is plentiful, continuous washing may be feasible. Most plastic tanks (like this Paterson) allow the water to be directed down the central core, so as to ensure through changing of the water with no 'dead spots'. A five to ten minute wash at 16C/61F or above should be adequate. If you are paranoid, or if the water is very cold, give ten to twenty. If you used a hardening fixer, give half an hour or more.

washing

 

Wash aids and pink stains

There is absolutely no need to use any sort of wash aid or hypo eliminator if you do not use a hardening fixer -- though wash aids for film are quite popular among gurus who do not actually know what they are talking about.

Even when fully washed, some films may have a faint pink stain -- maybe even enough to dye the final wetting-agent bath a very faint pink. This is residual sensitizing dye and is no cause for concern. There is certainly no sense in extra washing, which is a waste of time and water. The easiest way to get rid of the stain is to leave the sleeved negatives (see below) in the light for a few hours, when the dye will bleach away. Otherwise it will slowly fade of its own accord.Prolonged fixing (5 minutes with fresh fixer, 10 minutes with nearly-exhausted) will help reduce the pink stain with Kodak T-Max films.

Wetting agent

This is a sort of ultra-pure detergent, used at very low concentrations (typically 1+200 to 1+600) to help the water run off the film without leaving drying marks. Several makes are available. Many gurus recommend using them weaker than the manufacturers' recommendations, and for once we agree, but if you go below about half the recommended strength they may lose efficacy: a certain amount depends on the hardness of the water in your area. It is very unwise indeed to use them stronger than recommended as this may cause drying marks in its own right.

The use of wetting agents is optional but most people find they help the film dry faster and cleaner. Because many photographers are pathologically mean, they use cheap household detergent instead of wetting agent. But the cost of proper photographic wetting agent is not very high, and a bottle lasts half-way to forever. In 2007 we were about half-way through a litre bottle of Agfa wetting agent we bought sometime towards the end of the previous century.

Allegedly, wetting agent can build up on plastic developing spirals if they are not washed carefully before putting them to dry. As we always transfer films to stainless steel for the wetting-agent bath, we do not know if this is true or not; but we know several other photographers who swear that they have never had a problem, because they wash their plastic spirals carefully.

Drying

The ideal way to dry is in a drying cabinet fed with filtered air, and this is what we do. For reasons we have never understood, unheated air gives fewer drying marks than heated.

Before we had a drying cabinet, we used to hang films diagonally to dry them. They dry MUCH faster (and therefore cleaner) this way, even in unpromising locations. In our house in Bristol, which we left in 1987, we used to pin them diagonally across the kitchen door, which opened onto the back yard, and they were still remarkably clean. You want them at least 10-15 degrees from the vertical, and 30 degrees is probably best. The water runs down to the edge of the film, where even if you do get drying marks, it won't matter.

A useful trick with 35mm film dried diagonally is as follows. Pin the top, but at the bottom, bend a paper-clip into an S-shape. Hook one end into one of the perforations of the film, and hook a short elastic band over the other. Loop the elastic band over the lower pin. The film is then kept straight during drying, but the inevitable slight shrinkage of the film does not rip the lower pin through into the next perforation.

elastic hook

 

To squeegee or not to squeegee?

Some people use double-bladed squeegees to remove water from the film before hanging it up to dry; some run the film between two fingers; some use a wrung-out chamois; some never touch the film. Some spin the films in salad spinners (still in the reels) to drain then further.

sleeve

 

Many in each camp are vocal that theirs is the only way. Over the last 40+ years we have tried all of them, and are firmly of the opinion that it doesn't matter very much. The miniscule risks of scratching with squeegees, fingers and chamois are countered by the way that the film dries faster and picks up less dust. Do whatever you think best. Do not believe anyone who tells you that their way is the only way.

 

Sleeving

Once the film is dry, the best way to store it is cut in lengths in archival sleeves. We use PrintFile, which we believe are the best available. They are also sufficiently transparent to allow contact prints or reference scans (NOT high-resolution scans) to be made through the sleeve.

 

A number of the pictures in this module are taken from our book Darkroom Basics -- and beyond

Go to the unillustrated list of modules (in either alphabetical or date order)

or go to the illustrated list of modules

or go to the home page

 

© 2007 Roger W. Hicks