Bigfoot Field Researchers Organization Logo

Graphic Case Closure on the Crook-Murphy "Bell" Story

By Dr. Henner Fahrenbach


Fine linear, crisp details in highly magnified images of the sasquatch in the Patterson movie of 1967 were recently described by Christopher Murphy and publicized by Clifford Crook as evidence of a man-made object, a bell, adhering to the figure. The explanation resides in imperfect enlargement of an intermediate printed, screened image. The final image at high magnification contains artifactual details resulting from the haphazardly reproduced screen, which was only minimally enlarged. This finding, a methodological artifact, does nothing to discredit the authenticity of the Patterson movie.


I have in my possession a number of 8x10 pictures, sent to me by Christopher Murphy for evaluation of the significance and origin of the bell-like image, described by him and publicized by Clifford Crook. They were produced by copy machine enlargements of partial Patterson movie frames reproduced in "Manlike Monsters on Trial", edited by M. Halpin and M. M. Ames, available from University of the British Columbia Press. As will become evident, there is no hint of fraudulent manipulation of the pictorial material nor willful deception.

I have extracted the magnification of all pertinent pictures and have calculated the theoretically possible resolution on the various prints by data from Kodak (see simultaneous posting to this list). Mr. Murphy has kindly sent me a detailed description of his methodology.

Common Sense Considerations

As a first approximation, it should have appeared suspicious (rung a bell, as it were) that a rather crisp detail, the "bell", should have been visible at about 440x in the Murphy pictures, which are derived from an image that is decidedly fuzzy at 110x (the Halpin and Ames picture). That original softness is due partly to minimal camera and subject motion during the exposure, but primarily to enlargement well beyond productive levels of magnification. Thus, plain common sense militates against the reality of this paradoxical finding. The very fine screen used in the excellent Halpin and Ames reproductions might seduce the observer into believing that they are photographs. They are definitely prints with the usual printer's screen overlaid on them, a fine grid of dots.

Film Resolution Considerations

The calculation of resolution in the prints (as derived from the original movie emulsion; see previous post to this list) produces a value for the smallest resolvable picture element, in effect a pixel, which is of a size, optimistically, of at least the entire bell, approximately 2 inches at the level of the sasquatch. That means that all the details, lines and outlines, seen in the "bell" image, speak of a film resolving power that should be approximately ten-fold that stated by Kodak. Obviously, there has to be a reason for this paradox, since the detail is there for all to see, and yet the overall image is exceedingly fuzzy. This resolving power limitation by itself negates the claimed visibility of teeth, pupil, skin blemishes and nipple.

Methodological Considerations

The solution of this puzzle lies in the fact that Murphy used a screened, printed reproduction (at 110x) as the primary source instead of a photograph. He states in his methodology: "A. My original photographs of the picture in the Halpin book" [constitute his source material]. Any picture in Halpin and Ames, viewed with moderate magnification, shows the screening, a fine pattern of dots and short lines in several colors and combinations, as the printing process demands. In many locations, by happenstance, these dots will produce lines and other figures.

Consequently, the original information content of the image has been converted to dots, from which the preceding photographic image can never be reconstituted. The process of subsequent copying and reprocessing degrades and alters the image further. The information content of the image will remain forever corrupted by the printing step.

Had the printed image had been copied with proper photographic means, Murphy's final blowups would have displayed a visible, sharp grid of colored dots, reproducing at most areas of dark and light shading. In fact, the "bell" is not visible, by Murphy's own statement, in color prints derived directly from the original film. However, the copy machine reproduction, with its transfer of toner and subsequent heat bonding to paper with the inevitable smearing, is not capable of reproducing the fine screening pattern, but renders a picture that is deceptively smooth and photographic in impression. The image content, however, is only an averaged, smoothed rendition of the dot array.

However, due to random alignments of dots, localized sharp patterns appear. The reason lies in the fact that the screen, invisible to the naked eye in the Halpin and Ames frames, was magnified only 4 times (from 110x to 440x), whereas the partial sasquatch image shown by Murphy is magnified a total of 440 times (starting from original film level). Thus, seemingly sharp, though spurious, detail is incongruously embedded in an image that shows no substantive features on account of excessive magnification. Close scrutiny reveals other such random patterns in his prints, that have the same spurious origin. In fact, much of the field of Murphy's blowups has a "tweedy" or faintly cross-hatched look to it, evidence of the diffuse, smeared remnants of the dot pattern of the source, the screened Halpin and Ames print.

The next step beyond this level, the "bell" designation, is due to exuberant interpretation of random features in a manner reminiscent of earlier "discoveries" of straight and profuse canals on Mars, all a function of the observer trying to read significance into noise or imputing reality to random alignments. The rendering of a drawn bell image with totally imaginary detail, i. e., ornamentation, is inexcusable and is the only item in the entire affair that rises dangerously to the level of "manufacture" of data.

The debacle of the "bell" is due to several factors. As stated in a previous posting, enlargements for analysis can only be reliable if made from the original photographic image or at least an excellent photographic copy. Limits of resolution in any film can be calculated and applied to prints, but not ignored, exceeded or circumvented. It is a disastrous methodological mistake to copy a screened picture and to enlarge it for detailed inspection. Sub- standard reproduction methods, such as xerography or copying from a computer screen, compound the damage. To read significance into noise is human, but it can be avoided by thorough study of the subject at hand (and, as pointed out, common sense). The effects of premature publication with minimal peer review and dissemination to the press can only produce chagrin on all sides, when the results are eventually found to be an artifact of the method.

Corrective Considerations

Various double checks would avoid such interpretative fiascos in the future. For example, the large, commercially available Dahinden images, at 133x, should also contain the identical detail in slightly larger format, if it were real. So a compelling control would have been to replicate the entire process starting from the Dahinden frames. If these were xerographically enlarged to the same level as the previous set (440x), an entirely different image would emerge, since the Dahinden pictures are also screened reproductions. However, their screening pattern is of a different geometry, diagonally crossing lines rather than crisp dots, and different size relative to the image content. If the "bell" were real, it would show up here as well, if not better, but enlarged inspection of the pertinent area only shows an orderly array of screen lines.

Another compelling control for the reality of any image component can be produced by registered superimposition printing of a few adjacent, but separate movie film frames onto the same print. The process will increase contrast and detail of real structures, which are present in every frame, but will smooth out photographic noise or grain, which is randomly different in every image. This option is probably not open to anybody at this stage nor need it be explored in light of the preceding discussion.

The entire episode should serve as a cautionary example, to wit, that it is not safe to disregard the customary replications, controls and critical peer review common to the scientific process, and that the credulous press cannot serve that purpose. It provides a warning not to read more into fuzzy images than common sense suggests is visible.

Patterson Film Resolution

In view of the renewed vigor that the Patterson movie frames are being examined, I will repost this discussion on resolution (with verifying recalculation and minimal changes) that went out about a year ago. Usually such examination is done on prints that are magnified to or well beyond the limit of profitable enlargement with the result that the optical "noise" of the emulsion, usually called the grain, assumes a life of its own and invites spurious and fanciful interpretations. In order to give would-be analysts a cautionary yardstick, I provide the following details and calculations.

The resolution of a film, as stated in Kodak handbooks, is determined under laboratory conditions, as for example on an optical bench, by photographing a black and white grating pattern, meaning 100% contrast modulation, onto the film. If one uses a grating whose spacing gets tighter and tighter, there is a point at which the adjacent lines smear into one another and can no longer be separated. That is the stated resolving power of the film. This resolving power cannot, of course, be realized under photographic field conditions, since A) the camera isn't mounted on a solid pier; B) more importantly, real life scenery does not have close to 100% contrast of closely adjacent objects, and C) transfer of the available contrast from scenery to film (modulation transfer) occurs in an imperfect fashion. However, contrast contributes in an important manner to the smallest detail that can be detected in the final print. Additionally, any part of the intervening optical system, for example the camera lens, the enlarger condenser (if any), the enlarger lens and the coherence of the enlarger light source affect the resolution of the final image and will always degrade it from the optimum stated for the film. Multiple serial reproductions exacerbate these problems substantially.

The emulsion that was used by Patterson was, as far as is known, Kodachrome II. That film has a stated resolving power of 63 lines/ mm. In addition, Nyquists's Sampling Theorem states in its simplest fashion, that for a signal (minimal image element) to be detected, you need in effect the space of two lines, which brings the resolving power to 31.5 lines / mm. Stated differently, the smallest interval that can reliably resolved (under optimal conditions) in this film is (1 mm =1,000µm) divided by 31.5 lines = 31.7 micrometers or microns on the film. This is the physically limiting value for Kodachrome II, below which you may see assorted patterns that are part of the emulsion, but that carry NO image information and are, by definition, background noise. Advanced image manipulation techniques can modify contrast, edge sharpness and other aspect of the image, but cannot generate signal from noise and put the interpretation at risk.

It will be apparent at this point that all this calculation can be done without reference to an actual picture. One is dealing, after all, with a plain physical process that is well understood and for which the pertinent literature is voluminous.

The stated resolving power pertains to the original negative. To find what this value of 31.7 microns corresponds to in the prints in circulation, one has to know the magnification. When one does crucially important enlargements, one should print a transparent millimeter grating directly at the same settings as the original negative, whereby one generates a reference of the magnification. Since this is not available, one has to extrapolate stepwise from the size of an original 16 mm frame (at 1x) and scale it up to the larger images, a process that accumulates errors but still provides a good "ballpark" figure.

A good starting point is provided by the images in Perez' "Bigfoot at Bluff Creek" (1992; BigfooTimes; D. Perez; private printing. 10926 Milano Ave., Norwalk, CA 90650) He shows a one-to-one contact print of a bit of 16 mm film for calibration and a slightly larger image, which includes the frame, at 11.3x. Beyond that point it becomes necessary to find crisp fiduciary marks in overlapping pictures of different magnifications to extrapolate further. Thus, the Dahinden commercial picture of the full frame No. 352 (wide format) is approximately 37.5 x, the Dahinden vertical pictures of Frames 323 and 352 are magnified about 133 times, and the Halpin and Ames pictures are about 110 X (Manlike Monsters on Trial, University of British Columbia Press, 1980).

Some pictures that have been circulated of Patty's head alone can be calibrated by the preceding pictures and have been found to exceed 1,000 fold magnification. For the Patty rear view pictures, information available from NASI indicates that the large Dahinden pictures are at exactly a third of the magnification of the sideviews, i.e., 44 times, the Halpin and Ames picture 22 X. If one multiplies the maximal possible resolution that this film allows with the magnification, one arrives at a value that constitutes the absolute smallest resolvable detail in the pertinent print. This value will inevitably be overly optimistic (too small) because one is not dealing with a stark black-and-white image nor a steady camera. For the vertical images (Frame 323 and 352) this value is (133 x 31.7 microns) = 4,216 microns, or 4.2 mm. Cut out a paper circle with this diameter and it will approximate the smallest detail (optimistically) resolvable, slightly over 2 inches on Patty's body. (Actual resolution, for the above-mentioned cautionary reasons is apt to be worse than that, possibly by half) Upon inspection of this juxtaposition, the resolution in these large pictures picture is virtually the same as the largest blobs like the nose and the ear projection, but anything below that level of detail does not contain information. This maximal resolution is clearly discernible in the 133 x pictures, which have lots of empty magnification even though that makes it a little easier to look at them at a distance.

Thus, there can be no talk about detecting individual strands of hair, insect bites, skin blemishes, the pupil, teeth or other similar fine detail. Actually, everything there is to be seen in the pictures is visible with the naked eye at 50-100x magnification, i.e., surprisingly, common sense prevails in "what-you-see-is-what-you-get". Thus, finger or toe detail, that should lie in the vicinity of this 2" limit, does not show up crisply at all. Any conclusions based on supposed detail below the stated limit are largely a function of the imagination of the examiner, should be viewed with grave suspicion, and would require heroic proof to be convincing. Analysis based on anything other than direct copies of the original film frames is also to be avoided at all cost due to the above considerations.

  Copyright © 2014