Thursday, June 7, 2012

P40: coloured filters with black-and-white film

Once again I am approaching this project as an exercise in Digital processing, but this time actually taking the images to B&W.  In a former course, "The Art of Photography", I actually shot B&W using coloured filters but with a Digital camera. The effects were exactly as was suggested in the text.  Of course light is modified by the filter and whether the imaging place is film or silicon the affect is the same, but only if the white balance of the camera is established first for the scene without filter and then maintained at the same value for all shots.  My blog entry for this can be found at  

Having experimented successfully with filters and a digital camera, I felt it was more useful to approach this exercise from a fully digital stance, i.e. take existing images and exploring the processing options within my workflow tool, Lightroom.

The first shot was a dramatic sky shot in the Northern reaches of the Englischer Garten. The starting shot has been processed in Lightroom using my usual strong colour/contrast, becoming a bit of a habit or perhaps a visual style, who knows.

My next step was a straight conversion to B&W without any adjustments to the colour channels (in fact I took the default Lightroom conversion and reset all the colour channel adjustments to 0).  This produces a rather bland but acceptable image.

Next applying the yellow filter in software, the biggest affect is that the sky darkens and gains more contrast, but at the expense of also darkening the foliage at the bottom of the screen.

The red filter has a limited affect on the image, suggesting that the software implementation is not well tuned to the process

The Blue filter lightens the sky and darkens all else.

I did not find any of the software filters particularly satisfactory, they do not really emulate the affect of a "real" filter with B&W film.  Using a filter at the time of shooting also makes no real sense as all it does it reduce the amount of information in the resulting digital file, information that can be usefully exploited later in the process.  I finish with a conversion to my own taste, an image that looks very much more like a red filtered photo.  I have heavily reduced the blue channel whilst pushing the yellow channel to preserve the tree detail.

For the second photo, one with plenty of Green vegetation I have chosen a shot taken during the development of assignment 1 at the Olympic park.

No filter

Green filter

Red Filter

Once again the affect of the software filters is rather weak and unsatisfactory.  It is so much better to manipulate each colour channel directly.  I decided that I wanted a higher contrast image and so have pulled down the Yellow and Orange channels.  I left the green channel alone, for "Green" foliage the yellow channel has a higher impact as much of the luminosity of the leaves is a reflection of sunlight.

Finally I have dug into my holiday pics for a richly coloured sunset, this is from Gangga Island of the coast of North Sulawesi in Indonesia.  It is by far the most dramatic sunset I have ever seen.

No Filter

Blue Filter

Red Filter

With such strong primary colours in play the filters are having a far more dramatic affect than before.  The blue filter has made the image very dark as red was the dominant colour.  Conversely the red filter has brightened the image substantially.  Indeed the red and blue filtered images almost appear to be negatives of each other.  Once again by directly manipulating the colour channels I can arrive at a far more satisfying balance of tones within the image.

During the past 4 projects designed to build skills and familiarity in working with B&W film and printing I have taken a distinctly digital approach and in most cases actually considered the problem in colour rather than B&W.  I do work in B&W, indeed my second assignment was such, however the advent of digital means that many techniques from processing B&W film can now be applied to colour imagery.  These were useful exercises reinforcing skills I had already partially developed, but with some of the new learning I have been able to revisit portfolio shots and make some subtle but telling improvements using selective modifications to the tonality of regions of the photograph.  I suspect that any rewrite of the course will see changes to this section, however, it was very valuable even if I did change the rules once again.

Returning to the subject of this project, B&W filters.  Whilst they can be used with a digital camera, there is limited value in doing so and their use probably removes much needed processing latitude that can be applied later in the process.  The so called filter presets provided even in software as good as Lightroom also have a limited value.  Why emulate static effect when you have an almost infinitely adjustable toolset.  Digital B&W brings with it a far greater ability to place an images tonality wherever the artist wants it to be.  This can be overdone and purists religiously adhering to the zone system would disagree with anything I write here, however, the ability to adjust colour channels individually has brought B&W alive for me and provided me with a new form of graphical expression.

Given the benefits from Digital workflow to B&W expression the introduction of a digital camera that captures no colour information at all, the new and hideously expensive Leica monochrome, makes so little sense, I wonder what the point is.  OK digital is still faster than film, but if you want to abandon the post processing benefits why even bother to shoot Digital, a second hand film Leica will probably outperform the new digital model and has the benefit of being able to shoot different film types.  These can be emulated in processing, but only if the colour channels are present as the emulation requires information about colour as different films have different sensitivities to colour.  Perhaps a toy for the wealthy experimenter.

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