Black and White versus Colour Photography
Post on 02-Jul-2016
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Black and White vevsus Colour Photography WILLIAM R. CRAMB
Detective Superintendent, Photographic Department, Finger Print Branch, Metropolitan Police, N e w Scotland Y a r d , London, England
Photography i s a n invaluable aid in police work, Particularly in the presentation of court evidence. T h i s article presents some arguments for and against the regular use of colour photography.
Unti l now the disadvantages in the regular use of colour photography have prohibited i ts use in forensic work. These di$culties have been mainly financial and technical. Although the financial consideration still remains, m a n y of the technical di@culties no longer exist and colour @hotography can now meet the requirements hitherto fulfilled somewhat inadequately at times by black and white photography, with the advantage of greater realism.
The title Mr. President, Ladies and Gentlemen, is not mine, but was thrust upon me. I t suggests an unceasing struggle between warring divisions of photo- graphers, cameras a t the ready, a struggle where one must use one or the other, but not both. A situation where black and white is the be-all and end-all of photography and preferable to colour. This would suggest that witnesses should be fitted with blinkers and glasses to filter out colour. A grey look- out indeed, and a situation manifestly absurd. Such is far from the truth, and I trust that here, a t least, in this learned body there will be no colour bar.
I would prefer to treat this talk as an examination of the case for tlle use of colour in forensic photography and although I tend to take tllc view that just as 'Hi Fidelity Radio' followed and is complementary to the 'Old Steam Radio' so colour photography is the natural corollary and logical advance on its elder brother, black and white. I will, however, endeavour to discuss the subject as dispassionately as I can.
The question as to whether monocllromatic or colour pllotography should be used in forensic work is not a clear cut black and white (no pun is intended) but is hedged around by many difficult and complex points, to say nothing of prejudice. Before a decision can be made, economy and time factors must also be taken into consideration.
Forensic Application of Photography I t may be of some value a t this stage to ask oncsclf, what is tlie purpose of
photography in law enforcement work ? Only two years after the invention of photography itself by Daguerre in 1839 its value in Police work was realised, and has been used increasingly until today it covers almost all aspects of crime investigation and is the handmaiden of scientist and detective alike.
Photography for forensic purposes is a practical means of obtaining a perma- nent pictorial record of sometlling wl~ich it is difficult or inconclusive to describe, and of recording for ever the things one sees for only a momcnt. I t can there- fore be used to :- 1. record the initial appearance of evidence. 2. record the scene of crime, or some aspect of tlie scene of crime, wllicl~
cannot be preserved in its primary state. 3. stimulate the memory of the investigator and aid him in the future
analysis of the crime. 4. to check the reliability of witnesses and their statements.
5 . provide a means of making visible for all to see, various aspects or details of evidence not visible to the naked human eye.
6. preserve and record all perishable clues. 7. circulate descriptions of 'wanted persons', 'stolen property' etc. 8. provide one of the easiest and best means of illustrating evidence in
Colour to Replace Black and White How then does black and white photography measure up to these require-
ments ? For many years it has been the accepted practice to photograph all major scenes of crime such as murder, manslaughter, suspicious death, arson, grievous bodily harm, assault and so on, and the cases where bodies are concerned to follow this up with record photography at the mortuary, of wounds, post mortem conditions, and other details such as ligature markings for the use of the investigator and more particularly the pathologist and scientist. Such photographs have been accepted in Court as a valuable adjunct to the better understanding of the case in hand. These photographs however can only show in monochrome that which, is after all, in colour. Subject to some qualification it would seem that such photographs in colour must be more accurate and give more realism to the understanding and the quest for truth. Here then is one aspect of forensic photography which might benefit from the use of colour.
Probably the largest single aid to the crime investigator and without doubt one of the most successful, is the science of fingerprints. Fingerprint photography demands considerable skill and a great amount of work from the photographer. In this field I can see no advantage in using colour, and indeed the very nature and essence of the work is speed, and colour by virtue of its very much longer processing time would defeat this aim. Equally I can see no place for colour in the photography of forged and suspect material, nor when using ultra-violet or infra-red rays, although it is possible that where colour is the sole factor in document examination, colour photographs might be of some help. By and large, black and white is adequate and meets the exacting demands of such work. . . - . . . .
Black and white photography is also used extensively in criminal record photography of convicted persons, and here at least there is room for considerable improvement. Colour is used extensively in this field in other countries, particu- larly America, where not only do they use colour prints but colour transparencies which are used to flash pictures on the screen in what are vulgarly called 'Line- ups'. This superficially would seem to be a good idea since not only can the pictures be scaled to same size but they can be contained and presented very much better than by putting small prints into an album. One objection to the use of colour here however, is that quite often witnesses may notice one colour- ful item such as red hair or a yellow tie, and may forget the salient features of the face and not finding these items on the photograph discard i t out of hand.
I don't intend to say very much in regard to the use of photography in the Laboratory not because it is not important, but largely because this is not my particular field. I would however suggest that in the record photography of the examination of hairs, fibres, dust and debris, etc., and some forms of comparison work colour photography could be an improvement on black and white, particularly where control samples are being photographed a t the same time.
Disadvantages in Colour Photographs as Court Room Evidence From what I have said so far I think you will agree that there is at least a
prima facie case to answer. Although colour photography so far as forensic work is concerned is no new thing (indeed experimental transparencies werebeing made at New Scotland Yard as far back as 1935) it is only in recent years with
the advent of user processing materials that serious consideration has been given to the use of colour by police photographers and the laboratories. These experiments were a t first directed to the use and production of positive trans- parencies, mainly I think because the technical quality of the transparency was superior to, and easier to produce than, the colour print. This superiority to a considerable extent is due to the method of viewing, by transmitted light, either direct with a small viewer, or by projection, whereas colour prints were opaque and dependent on reflected light with a resultant dilution and flattening of colour. Production and demonstration of transparencies in Court by pro- jection was found to be far from satisfactory, projection and the darkening of court rooms being looked upon with disfavour. Such being the case some method of daylight viewing, with back projection, or the handing round of a small battery illuminated viewer, was the only alternative. Both methods leave a lot to be desired. On the one hand, projection, by virtue of the seating arrangements in Court makes it difficult for all to see, and on the other if all are to examine the photograph in turn, this would be time consuming and could well lead to the situation, where members of the jury would be looking at the transparency long after it had been referred to. Also it might distract their attention at some more vital point of the case.
Such difficulties made it obvious that the well tried and proven method of presenting a copy print to everyone concerned was, and still is, the best method of producing photographic evidence. Recent improvements in colour material and improved user processing methods, to me an essential factor to the forensic worker, make it possible and practical to consider using colour prints. This does not of course rule out the use of transparencies, which are still techni- cally better. Indeed the high cost and long time involved in processing prints may necessitate, on these grounds alone, the continued use of transparencies, despite the drawbacks of illustration. I t must not be forgotten that, important as is court production, photography has many other uses for the forensic worker, for wl-iich purposes transparencies are ideal. Nevertheless it is from colour printing that I see the challenge to black and white if challenge is the right word.
Living in a world of colour as we do it is obvious that in presenting evidence, colour prints, honestly, impartially and objectively prepared should commend themselves to the courts, and should be judged solely by their relevancy and and evidential value. Particularly is this so in cases of wounding and assault, photography in the mortuary, and in the laboratory, where the addition of colour, must tend to increase the realism, truth and perception so much more so than can be the case with black and white.
Is a Photograph an Accurate Reproduction of a Scene I t is recognised that colour perception varies with individuals and indeed is
deficient in some, to the extent of colour blindness. Such deficiencies, according to some authorities, affect 1% of the population and are reputedly higher in men than in women. No doubt the ladies will claim this is due to female superiority, but i t is in fact attributed to the greater use of alcohol and tobacco by the male of the species. Colour perception and its interpretation may well be affected also by other factors, such as smell, temperature and experience. For example, on a clear sunny day where shadows are cast by a north blue sky, a colour photograph will show these shadows as blue, whereas the memory will almost certainly suggest that the shadows should be black and therefore reject the photograph as being inaccurate. Again, if a photograph is taken of someone wearing a white dress or shirt in evening light, in the resultant photo- graph the white material will appear as yellow. But since we know this material is white the viewer will again reject the print as false. We know however, that the colour of an object is governed by the type of light which falls upon it and by its absorptive and reflective properties, so that in the case
of the white shirt in the evening light, deficient in blue as it is, it can no longer be white but must be yellow.
Is it therefore asking too much of colour photography to produce an accurate colour print to meet these various deficiencies ?
I t is sometimes argued that a photograph, whether monochrome or poly- chrome, does not give a completely faithful reproduction of reality, since such a photograph must include an element of choice and that it does not produce what the eye sees which is a 'complex building up of a large number of pictures integrated by memory' but is a single choice, from a fixed point, further compli- cated by reduction from the three dimensional, to two dimensional context, and is therefore dependent on the honesty, impartiality and objectivity of the photographer. This of course is true, but it should be borne in mind that like any other expert witness, the photographer and his photographs can be checked, and his relative objectivity, and veracity, subjected to cross examination and proof. After all to submit as evidence faked or false pictures with intent to deceive is surely just as much perjury as any other form of falsified evidence and punishable as such. Despite these doubts cast upon the veracity of photographs by this form of argument they have been accepted in English Courts in their black and white form for many years.
Essential Requirements for Colour Photography I t is further argued that in relation to the introduction of colour photo-
graphs to Courts of Law that the following technical requirements are necessary.
1. Accuracy in colour. 2. Durability. 3. Reproducibility.
This would seem to arise from the premise that black and white has these technical requirements, since they are already accepted as evidence. Certainly black and white prints are durable and reproducible, but surely far from accurate even in tone colour and I would have thought that bad colour is better than no colour at all.
With regard to durability it cannot be denied that colours do change under adverse conditions, but in my experience and that of many more experienced workers in the field of photographic science, such changes do not materially affect the overall appearance of the picture, and certainly do not locally affect one colour to the extent of deceiving one, into thinking that it was something radically different. Despite this the colour stability is such that under all normal conditions colour prints will outlast their possible usefulness in regard to police purposes.
Modern processing methods of colour are such that no difficulty need be experienced in the last of the technical requirements, and indeed the processing procedures allow of very few changes which can be made by the operator. a factor which reduces the likelihood of the photographer influencing the finished result by manipulation, something that cannot be said for black and white.
Weakness in the Use of Colour Photography There are however, inherent weaknesses in colour print photography which
must be carefully controlled. I t is possible for instance, when making up the fllter pack, used to compensate for different paper batches, exposing equipment, and colour balance, to miscalculate and so produce a colour bias which would give a false shade of colour to the print. This print for all ordinary purposes might be acceptable, but in forensic work could lead to a situation bringing discredit on the evidential value of the photograph, particularly so if the photo- graphic evidence was intended to convey a particlar shade of colour. For this reason alone it is risky to use colour prin...