The Negative Advantage

In some ways I miss shooting sharp, high quality colour negative film. For a time I felt it had advantages over digital, but it was hard work getting the results I was after.

The highlight detail in colour negative film develops more than the detail in the shadows. This means negative film can easily withstand a stop or two of overexposure. Overexposed negative film will retain more highlight detail than slide film (and may compete very well digital captures, too), and the detail in the shadows will also increase.

The layers and chemicals in overexposed negative film will work together to reduce grain and enhance sharpness. But it’s important to remember that pushing the film too far will cause these gains to break down. So just a stop or two is ideal.

Colour casts are significantly reduced when negative film is overexposed. When exposed normally to daylight, each layer gets sufficient exposure, but if the prevailing light source is unbalanced, an unpleasant cast will result because one or more of the layers gets too little exposure.

Overexposure will boost the starved layer without harming the others. So the orange glow so typical of indoor light and the greenish cast from fluorescent light will be less noticeable. Again, too much exposure will undermine the benefits.

Scanning Colour Negative Film

Frustratingly, in photo magazines and online forums, 35mm negative film was frequently referred to as “print film”, preferred by amateurs for economy prints and unpopular with pros. Even though viewing slides to get the best from them wasn’t exactly convenient, for decades many advanced amateurs preferred slide film partly because the alternative, negative film, had to be printed and was therefore a second-generation image. When good quality consumer film scanners became available the balance shifted significantly. Both slide and negative film originals could be scanned and even multi-scanned in great detail and the resulting images digitally printed. In my opinion this process revised the traditional gap between colour negative film and slide film.

Good consumer film scanners allowed the modern amateur to work at home on original images. Scanning and image-editing software programs could be used together to impressively control the wide tonal range, contrast, colour saturation and grain. In fact, software techniques can be used to selectively minimise the effects of grain so that it’s not a defining issue in the final print at typical viewing distances. 

Shooting fine-grained colour negative film allows you to hold excellent shadow detail while largely avoiding the pitfall of the lost highlights, a persistent problem with slide film and digital capture. Exposing colour negative film properly is fairly straightforward. The sharp, tonally rich negatives give you more information to work with in the digital darkroom where tonal and colour information in 20+MP images can be manipulated creatively to produce quality, saturated digital custom or machine prints. As with all digital images, it’s also possible to produce impressive black and white prints from colour originals.

An issue with shooting colour negative film is getting quality scans that make good use of colour and tonal information across the range. For that we need a decent 35mm scanner that captures very good highlight and shadow detail. Unfortunately, some labs may not produce the results we need. Note: 35mm film attachments for quality flatbed scanners cannot compete with dedicated 35mm film scanners.

The image top-left is an auto scan made when the film was processed at a local lab. The poor result is almost certainly due to automatic processing. The manual scan of the colour negative frame has deliberately held the delicate highlight detail (too fine to be seen on the histogram, above right). Shadow detail is excellent. Neither image has been edited. The turn-around time at a mini-lab can be exceptional, digital prints from your prepared files should be acceptable, but film processing standards can vary. Incidentally, although the Fuji Reala film was 3 months out of date and had been poorly stored, it produced quality negatives. And, if you’re interested, the blooms belong to the Calico Bush (North America).

Slide Film or Colour Negative Film, or Digital?

Particularly in the context of scanning for prints, what’s the real difference between 35mm slide film and colour negative film?

Various terms are used to describe the inherent properties of film. The curious amateur photographer will read about exposure latitude, dynamic range, tonal range and even scenic range. To simplify this diversity you only need to understand that slide film and negative film respond differently to the tonal values in the scene you intend to record. Or, to put it another way, the range of illumination in the scene, all the way from the darkest shadows to the brightest highlights, will be recorded slightly differently depending on the choice of film, negative or postive.

Colour negative film’s propensity to hold very good tonal values accounts for its much wider exposure latitude. Colour negative film has lower contrast properties than slide film and will cope quite well with highlight and shadow detail throughout the frame, perhaps up to five stops of light at the extremes: three overexposed and two underexposed. In real world amateur photography this means that properly exposed fine-grained colour negative film will capture very good shadow detail while also retaining subtle tonal gradations in the brighter areas of the scene ā€” clouds, for example, or sunlit Caucasian skin tones. 

So, because negative film copes so well with highlights, before you take your shots you should try to make sure you’re capturing as much relevant detail in the shadows as possible. Colour negative film, with its broad gradations of tone, is ideal for scanning because there’s a lot of useful information across the range to work with on the computer. It’s a luxury being able to ditch tonal information when you feel it benefits the image!

However, when compared to slide film, colour negative film’s wide exposure latitude usually means the recorded image has less contrast and saturation ā€” it appears to have less bite. More than that, the orange mask built into negative film can present unique problems, with consumer scanners offsetting its effects with varying degrees of success. As a result, getting the best colour balance may occasionally take a little effort when scanning. However, scanning techniques and image-editing software could inject punch and zest into digital images from colour negatives and this in turn means more vibrant prints. In other words, you can give them more bite if you wish.

Positive (slide) film typically has more lively contrast and vivid colour than negative film. It also exhibits smoother tonal blends and remarkably fine grain. It’s unfortunate then that it struggles to hold detail in the highlights, and very dark shadows can be rendered almost black. Before exposing slide film it’s best to make sure preference is given to brighter areas of the scene. It’s possible to compensate for the wide contrast range in a landscape scene by using graduated filters. The slide photographer can also use typical image-editing techniques that impressively expand the exposure latitude of any scene by combining two or more scanned images.

During the evolution of digital cameras, sensors have often shared slide film’s highlight problems yet could get more from the shadows. The very best of modern full-frame camera are now capable of impressive dynamic range. Shadow retention will be particularly good if the exposure, when appropriate, is routinely pushed just short of blown for key areas of brighter tones and detail, and unprocessed and uncompressed data is captured rather than JPEG only.  

Sensor pixels, or light receptors, wrestle with bright light because their response to it is not gradual. Instead they peak quite quickly, totally losing highlight data. In-camera software manipulation can produce helpful results. It’s certainly an irritating problem that makes some digital exposures quite tricky, a bit like shooting slide film, and debatably it’s likely to be an integral part of digital technology for some time to come.

Regardless of how you produce your digital images, it’s worth remembering that tonal information will always be lost in a machine print. Other modern print processing techniques are delivering impressive results that better reflect the work done in software that has selectively expanded the range of tones. Using layers and masking enhancements in ON1 software is a good example of this. This underscores how important it is to familiarise yourself with the finer details of digital image processing and so make proper use of the digital darkroom.

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