Half a century ago, Belgian Zoologist Bernard Heuvelmans first codified cryptozoology in his book On the Track of Unknown Animals.
The Centre for Fortean Zoology (CFZ) are still on the track, and have been since 1992. But as if chasing unknown animals wasn't enough, we are involved in education, conservation, and good old-fashioned natural history! We already have three journals, the largest cryptozoological publishing house in the world, CFZtv, and the largest cryptozoological conference in the English-speaking world, but in January 2009 someone suggested that we started a daily online magazine! The CFZ bloggo is a collaborative effort by a coalition of members, friends, and supporters of the CFZ, and covers all the subjects with which we deal, with a smattering of music, high strangeness and surreal humour to make up the mix.
Unlike some of our competitors we are not going to try and blackmail you into donating by saying that we won't continue if you don't. That would just be vulgar, but our lives, and those of the animals which we look after, would be a damn sight easier if we receive more donations to our fighting fund. Donate via Paypal today...http://forteanzoology.blogspot.com/2009/06/giant-anaconda-plot-thickens.html
http://forteanzoology.blogspot.com/2009/06/great-snake-or-no-great-shakes.html
http://forteanzoology.blogspot.com/2009/06/more-on-saga-of-peruvian-giant-anaconda.html
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2 comments:
Basically, the process of inferring size data from a photograph is called photogrammetry. It depends on the fact that the transformation from object space to image space is linear, apart from lens distortions at the edge of the field. The ratio: (object size)/(distance from object) is equal to the ratio: (size on image)/(focal length). To put it simply, if you know the scale of the image, such as 1000:1, you can measure the size of anything on the image and multiply it by the scale (1000) to get the true size.
I assume you know the height of the aircraft (how?). You need to the know the focal length of the camera. If you were using a camera with variable optical zoom this will be impossible unless you know what setting you were on (such as maximum). If you know this you may be able to look it up in the manual or, better still, treat it as a measurable quantity. With the camera on the identical setting photograph an object of known size from a known distance: this gives the scale factor immediately. Of course there are complications if you were viewing the object on the slant, since you will need to correct for perspective foreshortening.
I hope by the way you used a film camera. You are less likely to get sneers about Photoshop if you can produce a negative. Also 35mm film has more image detail than any except the very best professional digital SLRs. If you have film get the negative scanned and digitised; a drum scanner is best. If it was a digital, than I hope you set it to 'low compression', or all the fine detail has been lost!
I hope this helps.
Thanks
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