irreproducible results

Many photographers, perhaps most, have a wildly exaggerated idea of how much precision and repeatability is available in the photographic process. This is principally a module about what the variables are in real life, and their possible magnitudes. There are over two dozen of them. There are also quite a few observations on how equipment can sometimes be crucial. Time and again, we find ourselves saying, "No, there's no point in trying to replicate 8x10 inch Hollywood portraits with 35mm or medium format, and even 4x5 inch may be difficult -- but try 8x10 inch (and preferably an uncoated lens) and you may be surprised at how easy it is."

Not everything in here applies to all types of photography: for example, digital photography doesn't have the chemical processing steps, and slides are rarely subjected to the same variations in processing as black and white. Even so, what follows can explain a lot.


decanter crop




A lot of the time the different variables will cancel out, but it is possible for them all to add together and to give truly impressive cumulative effects. Also, many depend on personal variations in equipment and technique, so while it is fairly easy for a single photographer with a single set of equipment to be consistent, it may be difficult (or even impossible) for someone else to replicate their work, especially with different equipment and often unexamined differences in technique.



The first and easiest way to start to try to replicate a given effect is to find out how it was done in the first place. You might guess that this was shot with an old-fashioned (and no longer available) ultra-fast film such as Ferrania 1000D, using a flary lens such as a 135/1.8. This would give a similar effect but in fact it was shot with a Nikon D70 SLR and the unique Dreamagon 90/4 soft focus lens at its minimum aperture of f/11. The ISO speed was cranked up as far as it would go (1600) to create the 'grain' (noise), and the image was post-processed in Adobe Photoshop with 'Texture> Grain> Speckle' and some desaturation and brightness adjustment.


obsolete equipment

As noted in the introduction to this module, one of the easiest ways to re-create the effects of the past is to use the equipment of the past. This often means larger formats than are common today, including (as here) hand-held 4x5 inch. Of course, matching the subject to the equipment helps.


Wall of Death


Roger used an MPP Mk. VII for this shot, from the look of it with the 150/4.5 Voigtländer Apo-Lanthar for which he hand-filed a cam (the only other lens he had for the camera was a 90/6.8 Angulon). A small amount of subject movement, the result of a long shutter speed, adds to the vintage mood: films were a lot slower in the past. Film was Polaroid Sepia.


wall of death



wedding cake



specialist techniques

It is amazing how many people (including camera club judges) are unfamiliar with old techniques and 'alternative' processes. More than once, Frances (who has always been much braver about entering competitions than Roger) has heard the judge say of a winning or highly commended picture, "I don't know how this was done." Two of the techniques where she has heard this most are liquid emulsion prints and hand colouring, the latter with SpotPens which do not change the texture of the surface of the paper.

This picture wasn't a competition entry; rather, it was part of a wedding present (we don't do weddings, except for very old friends and one or two of their children). A picture of the bride dressing appears later in the module.



Wedding cake

Two of the easiest and most useful tricks when you are planning on hand-colouring are printing a little lighter than usual, or sometimes just with less contrast, and sepia-toning. The hand colouring blends in with the sepia to create a sort of generic nostalgia that many people have difficulty in separating from old, faded colour photography -- except that old, faded colour photographs rarely look so attractive! Frances shot this with a 50/1.5 Nokton on her Voigtländer Bessa-T, rating Ilford Delta 3200 at EI 3200



film speed 

ISO film speeds permit variations, batch to batch, of +/- 1/3 stop. Such variations are unlikely nowadays, but they are not impossible, so different batches of the same 'ISO 100' film may range from ISO 80 to ISO 125 in the same developer.

It is also far from unknown for manufacturers to round their ISO figures. On the one hand they may round ISO 90 up to ISO 100 (because who is going to buy an ISO 90 film?) while on the other (and rather more usefully) the speed aim point for an ISO 125 film may be ISO 140 or so, on the grounds that a little extra speed in a black and white film is an added safeguard against under-exposure.


Barge, Ramsgate


Many people adore Fuji Acros 100. We prefer other films. But either way, our tests (and those of others) indicate that it it is the slowest 'ISO 100' film on the market. This is no surprise as it is also the finest grained. Roger shot this with his Alpa 12 WA and 38/4.5 Zeiss Biogon; Frances printed it on Ilford MG WT.


acros tug

digital sensor speed

There are no ISO standards for digital sensor speeds: they are set by analogy with film speeds. Some manufacturers' analogies are better than others. Variations from one manufacturer to another of 1/3 stop are by no means unusual.

film age

ISO standards require speed testing to be done with a mixture of freshly-coated ('green') film and aged film. When a new film is introduced, there is no aged film so the manufacturers have to guess. Even if they guess right, speed variations of 1/3 stop between new and aged film would not be remarkable.

colour of light and film sensitization

This is seen at its most extreme with ortho films, which are typically twice as fast to daylight as they are to tungsten light, but the type of red sensitization can make a lot of difference too. A film with extended red sensitization may be as much as 1/3 stop faster in the early morning or late evening, when the light is red, than another film with the same nominal ISO. This can also make significant differences to the renderings of (for example) skin tones.


trees & clouds, portugal



The same arguments apply to filtration as to colour of light: if one film is more sensitive to red than another, a red filter may well have a significantly lower filter factor than it does with the less red-sensitive film.

What is more, a red filter will have a lot more effect on a blue sky, or under blue lighting, than it will on a red brick wall or under red lighting. The blue sky may go almost black; the red brick wall may go a very pale grey.




Clouds and tree, Portugal

Quite apart from the red filtration, which is why the picture appears here, this is a real 'irreproducible result'. Frances shot it on Ilford XP1 (no longer available) and it was then trade processed without a water wash and has faded somewhat as a result. Frances printed this version over 20 years later on Forte Fortezo because she didn't like the effect on her usual Ilford papers. To top it all, she had shot it with a camera she rarely uses any more, her Nikkormat FT3, and a lens she rarely uses today because it really needs a rebuild, her 90/2.5 Vivitar Series 1 Macro.



unique lighting

Sometimes, the light itself is what is irreproducible. Light breaking through storm clouds (or even plain old rain clouds) often delivers extraordinary effects, which look as if all kinds of filtration and post-production work have been done -- but a straight shot is all you need. The picture below is one example; the picture above is another, though in the black and white shot, filtration was used. Taking advantage of this sort of light is a bit like the old secret of good press pictures: 1/60 at f/8 and BE THERE!

storm light, bighi, malta


Storm light, Bighi, Malta


It had been raining all day and we got very few pictures, when just before sunset the sun came in under the clouds and give this extraordinary effect. We were on our way home but drove immediately to the nearest place we were likely to get a good view. We expected the effect to be over by the time we got there but in fact it must have lasted half an hour or so. This is scanned from an original transparency shot with a 35/1.4 Summilux on a Leica using Kodak Elite Chrome 100 EBX with no filtration. Roger bracketed heavily (see free module because you only see light like this, on a subject like this, once or twice in a lifetime. This is one of the darker brackets

subject brightness range

There is a whole free module on this, so suffice it to say here that a development regime that is ideal for scenes around Rochester, New York, may lead to negatives that give rather flat, dull pictures (or require harder-than-usual paper) if the film is exposed in Scotland, well north of Rochester. Equally it may lead to negatives that give overly contrasty pictures (or require softer-than-usual paper) if the film is exposed in Tokyo, well south of Rochester.

And both are only averages, so a clear sunny day in Aberdeen will have a longer brightness range than a smoggy or misty day in Tokyo.



subject brightness distribution

Two subjects with the same subject brightness range may have completely different subject brightness distribution. A white cat in a coal-cellar, or a black cat on a white sofa, may represent the same brightness range but if (let us say) the cat occupies one-tenth of the picture area, the distribution is very different. This can be important when metering, because you have to choose where to point your meter.


Cross, Monsarraz, Portugal


The subject brightness range in this picture is fairly normal, but the distribution is clearly abnormal, with a much greater percentage than usual of very light tones (in traditional 9-Zone terms, Zone VII, the lightest tone with texture) and very little below a dark mid-tone. Frances metered the darkest area in which she wanted texture (in Zone terms, Zone III) and then shot on Kodak Tri-X with her Voigtländer Bessa-T and 50/1.5 Nokton with a weak (2x) B+W yellow filter. The print is on Ilford Multigrade Warmtone.


cross & cobbles


reciprocity failure

All films are designed to be exposed across a limited range of exposure times, and outside those times, they will need extra exposure.

Reciprocity correction varies enormously. Some films require little or no correction from 1/10,000 second to 10 seconds. Others range barely from 1/1000 to 1/10 second, and may require an extra 1/3 to 1/2 stop at 1 second and as much as 3 stops at 10 seconds. The only way to discover this is from the manufacturers' own specification sheets, many of which (mercifully) are available on line. If in doubt, stick with the old rule of thumb which is that overexposure is a lot less harmful to negatives than underexposure, and give an extra stop. Bracket colour slides, in the direction of overexposure.

With colour films, it is not only exposure that needs to be corrected: the colour balance can also wander as the different emulsion layers get out of synch. This can normally be corrected by filtration but once again the only way to find out what you need is from the manufacturers' spec sheets.






The odd name of 'reciprocity failure' comes from the way that the Bunsen-Roscoe Reciprocity Law no longer applies. This states that you can always compensate for a change in aperture (more accurately, for the intensity of the light falling on the film) by a change in the opposite direction (hence reciprocal) in the duration of the exposure. Thus if you halve the intensity, you can simply double the exposure time. When this breaks down, you have reciprocity [law] failure.


Mearle's Drive-In, Visalia, California

A good rule of thumb is that if you can hand-hold the shot, reciprocity failure is unlikely to be a problem. As soon as you really need a tripod, things may start to change.

Remarkably, to the best of our recollection this shot was neither set up nor tripod mounted. We were in Visalia one evening and saw this. Roger had his Leica M4-P with him, loaded either with Fuji RF ISO 50 or Kodachrome 64 (he used both in those days, the late 1980s) and with a 21/4.5 Zeiss Biogon on the front: a lovely lens, but hardly a speed king. This was hand-held, wide open, at either 1/15 or 1/8 second.

The moral of this story is simple. When in doubt, shoot. You may not get a good picture. But if you don't shoot, you won't get one at all. But also, what modern lens and film can replicate that particular combination?

abuse of materials

You can of course use the colour shifts inherent in reciprocity failure to creative effect, but there are also all kinds of materials that can be used for purposes for which they were never intended. A lot of 'ultra-fine-grain' films were originally designed as microfilms, and require careful development if they are not to be hopelessly contrasty (as did Kodak Technical Pan, now gone and lamented by some) but we never liked any of these films because of the lousy tonality.


A range of materials that we did like, but which is now also gone, is Polaroid's 35mm films, and quite a common form of abuse that still possible today is cross-processing. This usually means processing slide films as negatives, though negatives can also be processed as slides. In most cases, the colours are harsh and unpleasant, at least to our taste, but we did find cross-processed infra-red slightly interesting.


Boats, Minnis Bay


Polaroid Polablue was a very slow film with almost no latitude: you can see here how the sky fades from reading to not-reading, and how the shadows soon disappear (the image is in effect a negative). Frances used her Nikkormat with a 17/3.5 Tamron, which accounts for both the vignetting and the violent perspective.



meter cell sensitivity

The spectral response of the photosensitive cell in a meter can vary quite widely from that of the human eye, which in turn is different from that of a film. The best meters normally use cells with the most useful range of spectral response, and may further correct this with filtration. There is however no guarantee that a meter cell may not have disproportionate responses to infra-red or UV, never mind the visible wavelengths.


minnis bay


Meter cell sensitivity is especially important if you spot meter different colours. The only meter instruction book we know that addresses this comes with Pentax spot meters. As a rough guide, taking dark leaf-green as 'average', a reading taken from a pure yellow requires as much as two stops extra exposure (as compared with the meter's indication); orange, about a stop and a half more; red or blue, about a stop more; and indigo or purple, as much as a stop less. The less pure the colour, the smaller the variation.

meter inaccuracy

If you compare several meters, with an identical standardized target that admits no possibility of user error, you will be doing well if they agree to within 1/6 stop; 1/4 to 1/3 stop would be normal; and variations of 1/2 stop or more are not unusual.





meter type

An incident light meter keys the exposure to the highlights; a broad-area reflected-light meter averages all the light, and recommends an exposure based on 'average' or 'standard' brightness ranges and brightness distributions; and a spot meter may be used to measure a highlight (ideal for transparency films), or a key tone (common in portraiture, where a diffuse facial highlight is often favoured) or a shadow (best for negative films). A through-lens meter may be averaging; or centre-weighted; or spot; or multi-point, in which case there is likely to be a complex processing algorithm to decide what weighting to accord the different measured brightnesses.


Mertola, Portugal


Roger shot this on slide film, so the easiest way to meter was incident. This keys the exposure to the highlights (the brightest whites with texture and detail) but sacrifices the shadows.

For negative film, the ideal would have been a spot reading of the earth in the garden at the bottom centre. This would have guaranteed adequate shadow detail there; highlights could then be controlled via development, softer paper, or dodging and burning. Note also the blue haze in the background and the slight divergence of the verticals, the opposite of the 'falling over backwards' effect. The latter is the result of a high viewpoint with a wide-angle lens (35/1.4 Summilux on Leica).

metering technique

Give two photographers the same meter and the same subject, and there is a good chance they will get readings that differ by anything up to a stop, though agreement to within 1/3 stop should be attainable if they both know what they are doing. Quite apart from where they point the meter and whether they angle it up or down, there are always those who will round up and those who will round down.

Give them different meters -- especially different types of meter -- and the scope for disagreement can easily hit a whole stop.



actual aperture and transmission

The marked and actual apertures of a lens seldom diverge much, but a quarter-stop or even a third-stop is not particularly unusual, especially with zooms at the marked maximum aperture (they may well be slower). With mirror lenses the effective aperture may be as much as a stop less than the nominal aperture.

Even if the marked aperture is mathematically accurate, the lens may transmit less light than is indicated, because of light losses from reflection and absorption. This is why movie lenses were calibrated in T-stops. A T-stop passes the same amount of light as a perfect lens of the same aperture. Typically, a T-stop may be 1/3 stop less than an f/stop, so f/2 would be T/2.2.


Morro Beach, California


Roger shot this with either our 800/11 or 600/8 Vivitar Series 1 'Solid Cat' mirror lens on a Nikon F. It was misty, and this was accentuated by the extreme focal length. The only hope was bracketing (see the free module) -- on shutter speed, of course, because the aperture of these lenses is both fixed and somewhat less than marked. Film was Fuji RF/RFP ISO 50.


morro bay


lens flare

Non-image-forming light bounces around inside the lens. Some is absorbed; some is reflected back out; and some ends up on the film as veiling flare. Because this non-image-forming light is more important in the darkest areas (where it may be a significant proportion of the light falling on the film or sensor) than it is in the brightest areas (where it is swamped by image-forming light), the overall effect is to reduce the brightness range of the subject.

Variations in flare are enormous. The best simple, multi-coated lenses have a flare factor approaching 1, i.e. a subject brightness range of 128:1 would be rendered as an image brightness range of 128:1. But a flare factor of 2 is by no means impossible, which would reduce a subject brightness range of 128:1 to an image brightness range of 64:1. An old, misty, dirty lens, or a non-multi-coated zoom, might have a flare factor of 4 or more.


lamp post



In black and white, flare is far less of a problem than in colour: you can compensate by increased development or harder paper. The tonality will be different, but some people actually prefer the effects they get with old (even uncoated) lenses which they maintain give them more 'open' shadows. In colour, as well as flattening contrast (much harder to control without digital post-processing) flare can add colour casts, especially blue (from the sky) in daylight and reddish under tungsten light.


Lamp post, Montreuil


Roger shot this with a lens that was one of the best of its day, a 105/3.5 Linhof-selected Schneider Xenar on a 'baby' (6x9cm) Linhof; both dated from the late 1950s or early 1960s. You can see even here that it is slightly flat and slightly blue; the latter was exacerbated because it was shot on Ektachrome 64, a notoriously blue film. Although this is easy enough to cure in Adobe Photoshop or a similar program, we prefer more modern, contrastier lenses for colour slides if at all possible.

camera flare

Light can also bounce around inside the camera body. A lot depends on how well it is blacked and baffled, and on the colour of the film: most film is quite highly reflective. Once again, the flare factor of the best bodies -- a new large format camera with a well blacked bellows -- may approach unity. With old box cameras, combined lens/body flare factors of 4 and above are commonplace.


pelopponese bay


Sunset in the Pelopponese

Older cameras and lenses are often more flary than newer ones. Roger shot this with an early-1960s MPP and a 1950s lens, a 150/4.5 Voigtländer Apo-Lanthar, on 6x12 cm transparency film (brand forgotten) in a Horseman roll-film back.

actual shutter speed

Few shutters give their marked speeds all across the range, even when they are new, and they do not improve with keeping. The fast speeds tend to be the least accurate, even when new. If a marked 1/2000 on a focal plane shutter is 1/1600, it is doing well, and 1/1250 is nothing unusual. The 1/1000 is likely to be 1/800 and only by 1/500 is the marked speed likely to be accurate when new. With age, all these speeds are likely to drift by 1/3 stop or sometimes more: we have a 1960s Pentax where all the marked speeds from 1/1000 to 1/60 are approximately a whole stop slow, i.e. they are twice as long as the marked value, and actually run from 1/500 to 1/30. Then the marked 1/30 is 1/20, the 1/15 is 1/13, and 1/8 and longer are accurate.

With leaf shutters, a top 1/500 is likely to be 1/400 at best when new, deteriorating to 1/300 with age. Over the same time-span 1/250 will fall to 1/200 and the rest should be quite good, unless the slow speeds get 'sticky' and lengthen.

shutter efficiency

This is most important with leaf shutters at high speeds. During the entire operation of the shutter, there is obviously some time while it is opening; some time when it is fully open; and some time while it is closing again.

Now consider the same shutter with the lens at full aperture and at f/16. At full aperture, the shutter will be part-open (opening or closing) for far longer than it will at f/16, where much of the part-open and part-closed phases will be masked by the diaphragm blades. What's this worth? A lot depends on the design and state of the shutter, but 1/3 stop is a fair guess.


china's great wall


Great Wall of China


Frances shot this on Kodak Tri-X on her Alpa, one of the finest cameras on earth, with her 35/5.6 Rodenstock Apo-Grandagon, one of the finest lenses. But because of the very short focal length of the lens, and the fact that it is mounted in a No. 0 shutter, the shutter is highly efficient and she finds she has to give a full stop of extra exposure in order to get the density and tonality that she wants. The print is on Ilford Multigrade Warmtone.



It is also worth noting that you are never going to get the same tonality in a 7x blow-up from 35mm that you will get from a 3x blow-up from 6x9cm, which is the format that Frances used (all Alpas are of course multi-format). Oh: and unless you used exactly the same filter (Tiffen medium yellow) you'd get slightly different tonality again.

delays in processing

This is a very interesting one. You might expect that the longer a film is left after processing, the more the image will deteriorate, and indeed this is generally the case: this explains why most manufacturers recommend that you process films immediately after exposure or at least chill them until they can be processed.

There are however a few studies that indicate a slight increase in film speed after a year or two, followed by a fall. It is not hard to see why these studies are few in number. First, who is going to set up an experiment that takes maybe half a decade, and second, who is going to be interested anyway? The few studies that exist seem however to agree that it can happen, at least with some films.

developer choice

Speed-increasing developers can give a true ISO speed increase of 2/3 stop or more, at the cost of bigger grain, while fine-grain developers can wipe off a stop or more. 'True ISO speeds' refer to ISO shadow speed and contrast -- see the free module on ISO speeds -- but it is quite common for developer and film manufacturers to quote development times which give usable EIs (exposure indices) under non-ISO conditions. Thus the same film may be developed to EI 200 in either a fine-grain developer or a speed-increasing developer, but the contrast will not be the same in both cases.


taragarh palace


All this is quite apart from tonality, which is completely a matter of personal choice. For example, Ilford FP4 Plus is around ISO 160-200 in Ilford Microphen, less than 1/2 stop slower than Ilford HP5 in Ilford Perceptol, around ISO 250. The FP4 in Microphen is fine grained and cheaper too, but we prefer the tonality of the HP5 in Perceptol.


Youdon at the Taragarh Palace


To be cynical, you don't need to worry as much about grain, sharpness or exposure with bigger formats. At a mere 3x enlargement, this 6 x 9cm nominal (56 x 84mm actual) negative is all but indistinguishable from a 168 x 252mm (61/2 x 10 inch) contact print, even with a fast film (Ilford HP5 Plus) in a speed increasing developer (Ilford DD-X). A slower film woud be even harded to tell from a contact print.



Another 'irreproducible result' is down to the lens. You could probably come very close to the tonality with a 3x enlargement from similarly processed HP5 exposed using almost any camera, but you'd have difficulty in shooting quite so wide an angle with most cameras. Frances used her 35/5.6 Rodenstock Apo-Grandagon (equivalent to 15mm on 35mm) on her Alpa 12 S/WA.



And no, you couldn't get the same effect with a 15mm lens on 35mm, regardless of film: it would be a 7x enlargement and you would lose the tonality.

developer condition

As for the state of the developer, the pH (acidity/alkalinity) of the water that is used to make it up may vary significantly, as may the hardness of the water which can affect developer uptake. This is before you consider the age of the developer and any oxidation or hydrolysis of the developing agents that may have taken place. Then there are even more variables if you re-use developer: not just exhaustion of the developing agents, but also hydrobromic acid build up. A 'fully seasoned' developer -- one that has been repeatedly replenished and is pretty much at equilibrium -- is wonderfully consistent but is likely to give 1 stop less film speed than the same developer, freshly mixed.

thermometer and temperature variations

Top-grade mercury-in-glass thermometers are likely to vary by 0.1 degree C or less (call it 0.2 degrees F) from the actual temperature, and that variation will be constant, i.e. repeatability is excellent. There are reports of mercury leaking away through invisible cracks but this is very rare. Take care, though, that the column is not fragmented.

Ordinary spirit-in-glass thermometers often vary by +/- 0.5 degrees C (call it 1 degree F) but are again reasonably consistent.

Dial (bimetallic) thermometers may vary by +/- 1 degree C (call it 2 degrees F) but can often be adjusted (calibrated) to other thermometers. Repeatability (consistency) of a good one is likely to be as good as +/- 0.2 degrees C or 0.5 degrees F.

Cheap digital thermometers may vary by more than +/- 1 degree C and may vary by +/- 0.5 degrees C or more from one reading to the next. Repeatability is frankly poor. Good ones are a lot better, but it is still worth checking them frequently against mercury-in-glass.


hotel, tarragona

Hotel, Tarragona


Although Kodak E-6 processing and compatible processes are far more standardized than black and white processing, there is still scope for variation. The Tetenal kits we normally use give instructions for varying colour balance via changing the pH (acidity/alkalinity) of the colour developer, and advise changing development times by up to about 30 seconds either way to adjust for your personal equipment and variations in different manufacturers' films.



You can also see here how 'wrong' exposure can be used to creative effect. Not everyone will like the effect. That's fine. What's important is whether the photographer likes it. Equipment forgotten (Leica or Voigtländer): Kodak Elite Chrome EBX ISO 100.

timing variations

Timers are pretty reliable, whether you use a lab stop-clock or a wrist-watch: variations of even 1% (negligible) are very rare indeed.

What is more important is when you start and stop timing. In adding developer, the two main choices are from when you start pouring, and from when the tank is full (a possible variation of up to about 20 seconds). At the other end, you can time from when you start emptying; or when the tank is empty; or (for maximum consistency) to the moment you add the short stop or fixer.



non-ISO development

As described in the free module on ISO film speeds, ISO standards require a certain contrast and take the speed point as a certain density. There are plenty of good reasons to use other contrasts and other speed points, but if you do, exposure indices may or may not match ISO speeds.

enlarger type

Point-source condenser enlargers give the maximum contrast, while completely diffuse sources give the least. The difference can easily equate to a paper grade, sometimes more, sometimes less. 'Condenser-diffuser' enlargers, with a large, diffuse light source and condensers, are somewhere in between. Different photographers often develop to different contrasts so that their 'average' negatives print on grade 2, 2.5 or 3 using their enlarger.

Pecs, Hungary


Frances normally prints with two enlargers side by side, a matched pair of Meopta Magnifaxes with Meograde variable-contrast heads. We find that with most films we need about 10 per cent more development than the manufacturers' recommended times, in order to et a print on grade 2 or 21/2 -- or if we use Ilford XP2, as Frances did here with her Voigtländer Bessa-T, 50/1.5 Nokton and 2x yellow B+W filter, we often need grade 3 or even 4.


3 friends


enlarger flare

This is much like camera flare, above, but often more severe. It is well worth checking the blacking of the enlarger bellows or focusing mount; of the enlarger lens panel; and of the negative carrier.

enlarger lens flare

Once again, like camera lens flare -- except that many photographers use enlarger lenses are older than their camera lenses, and after years or decades in the hostile environment of a darkroom, these may be surprisingly flary.


big ben lith



paper contrast variations

Paper grades are not standardized: one manufacturer's Grade 2 may be another's Grade 3. Even papers from the same manufacturer have changed over time, partly because of the ever-improving maximum densities (Dmax) of modern papers.

paper developer

Some paper developers give more contrast than others. As compared with a middle-of-the-road developer, some give half a grade or even a full grade more (the latter would be very rare) while others reduce contrast by a grade or more. And of course there's the state of the developer.


Big Ben lith print


Lith printing with substantially oxidized lith developer is very hard indeed to replicate. The technique will be the subject of another module but here it is worth making two points. The first is that because the developer is, by definition, all but exhausted, the degree of exhaustion is impossible to keep constant even from one print to the next. Very large volumes will make it easier. The second is that even a few seconds variation in development time -- after a ten or twenty minute wait -- can make an enormous difference to the final print.



hand coating

Hand coating is one of many processes that are prized by some photographers for their very aleatoriness. They have a good idea of what they want, but they also know that chance will play a substantial part in the final result -- not least, in this case, because it is extremely difficult to control the thickness of the coating. This is one reason why variable contrast emulsions are not usually offered for hand coating: the coating thickness will make more difference to the final image than the emulsion contrast.


Reculver Towers, Kent


Near the beginning of the module, we said that camera club judges sometimes say of Frances's pictures, "I don't know how this was done". This is one of them -- but the judge then went on to say that he'd have given it higher marks (it was Highly Commended) if he'd understood how it was done. The original picture was shot on Ilford XP2 using a Nikkormat and a 15/2.8 Sigma fish-eye. The texture can be replicated by using the same paper, but of course, the torn edge cannot.

reclver hc


louise dressing




print lighting

A print viewed under strong light will reveal more shadow detail than one viewed under weaker light. If rich, strong shadow detail is important, strong lighting is essential. Alternatively, increase contrast but reduce exposure if it is to be viewed under weak light.

personal preference

This is the one that trumps them all -- and it isn't even consistent. Many printers find that their style changes as they get older, usually tending towards more contrast. Whether this is changing eyesight or changing taste has not been well researched.


Louise dressing for her wedding


It might seem that the obvious approach here would be to use ultra-fast film such as Ilford Delta 3200, but Frances preferred the skin tones available with Ilford XP2 Super and therefore chose to use an ultra-fast lens instead, the 50/1.5 Nokton, on her Voigtländer Bessa-R2, shooting at full aperture. There is more shadow detail but she chose not to print it, preferring to let Louise's left leg go to a dark mid-tone for a more natural effect. One publisher refused to use this on the grounds that it was 'glamour', despite the fact that you can see Louise's mother Frances helping her get dressed...



the bottom line



Usable film speeds -- exposure indices or EIs -- can easily vary from a stop slower than the ISO box speed to a stop faster. Because over-exposure is usually so much more acceptable than under-exposure for negatives, many people believe that films should always be rated slower than the box speed. This will however result in lower sharpness and bigger grain (except with chromogenics such as Ilford XP2, where grain actually gets finer even though sharpness falls), so it is unwise to overexpose 35mm film too much. If you are using an EI that is more than half or twice the box speed, there may be good reasons for it, but equally, you may be relying more than is necessary on the inherent flexibility or latitude of the system.


daroca power lines




The joke is that many people who use very low EIs are erroneously convinced that they are working to a very high standard of precision.

Then, too, normal personal development times (in black and white) can vary from about -20 per cent to +50 per cent of the manufacturers' recommendations, even for 'average' subjects. For subjects with a very long tonal range, a further -30 per cent may be appropriate; for subjects with a very short tonal range, +100 per cent may be suitable.

Power lines, Daroca


When you try a new camera or lens -- this was the Zeiss Ikon when it came out -- stick with a film you know (here, Kodak EBX ISO 100) or you are changing too many variables at once.

A highly vocal group believes that the manufacturers' development times for black and white are always too long. They are wrong. They are too long for some people (including the vocal group). They are too short for others. That's why the manufacturers recommend establishing your own development times. But as a starting point, they're pretty good. As a manufacturer's representative once said to Roger, "Why would we lie? Spite?"



Julie and Holly

Frances shot this on Paterson Acupan 200 in an old Pentax with shutter speeds twice as long as marked (we didn't know this -- it was before we got our ZTS shutter speed tester). She rated the film at 125, with a middle-of-the-road developer in view, but Roger processed it in a developer that gave ISO 200 or so. At this point, it was over-exposed by close to 2 stops -- and Roger developed it for 10% longer than recommended in order to get the contrast she wanted. As we say, the process is flexible...


julie & holly


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© 2006 Roger W. Hicks