Imagine a Nautilus shell tilted to the surface of the X-ray sensor. The parts close to the sensor are sharp, the distant parts unsharp. Because the X-ray beam creates a central projection. The focal plane is the plane of the sensor, in focus are those parts close to the sensor.
The shell looks like entering the image or leaving it.
Different energies of X-ray radiation mean different transparency of an object. There is an example in my FAQ using a Nautilus shell.
Instead of compressing images of different energies to a single image today I subtracted the 70 kV image of a Nautilus shell from the 40 kV image.
The central parts of the Nautilus shell are more dense and show a significant higher difference. The core of the shell gets shiny. This is how it looks like:
In positive X-ray representation you can compare the results. Left hand is the compressed image of 4 different energy levels, right hand the difference image.
How does an X-ray look like with a complete, unsplit specimen of a Nautilus shell ? Will X-rays go through the object ?
My three Nautilus shells I bought in Crete are split specimens. The following approach will give an answer to the question. My composition of my shells is 3-dimensional and in nearly upright position. X-rays were then done with different directions of the radiation to study the effect.
The first image was obtained with radiation coming from the top. The native X-ray representation is with a black background. Historically this was a film negative. Radiologists speak of „transparent“ areas where a film is black. Consequently, white areas are called „opaque“.
The result of radiation coming from the top and slightly tilted shells gives different insights of each shell. The composition looks like a complex mathematical surface or some flying insect.
The inverted (or „positive“) representation is weightless and our mind starts to produce lots of phantasies about the composition.
The effect of colorizing an X-ray is not only graphically. It looks more natural.
The following image was obtained by combining the inverted image with a flat projection of a single shell to a single image. Now one gets an idea of the effect of the beam path.
A tilted beam path shows the a bit more detail of the „wings“. Tilt was about 30 degrees.
Tilt by 45 degrees shows more of a Nautilus as we know it.
How to communicate an erratic process in terms of an image ? The Iliadic greek were pirates of the Mediterranean with fast vessels, invading mainland from the seas, enslaving people, robbing stocks and much more.
The writing down of the Ilias was between 678 and 662 B.C., a time of Assyrian dominance and cultural superiority.
With three different Nautilus shells I bought last September on Crete I did this composition on my big X-ray sensor with 35cm x 43 cm and 170µm per pixel resolution. Two energy levels were necessary to get a high resolution image of the core of the Nautilus shells.
To overcome the look-and-feel of a medical X-ray it is a logical idea to invert the light. Black becomes white and vice versa. White means shining through of X-rays, black means opacity. It’s like a dream !
How to prepare a X-ray session ? What flowers suit to a Nautilus shell ? Where does color come in ?
I went to my gorgeous florist to have a look what offer she can make during wintertime. My phantasy were spinning around something ethereal or unrealistic. I bought some flowers with respect to their shape.
The Anthuria caught my eye immediately. The Tulip was still closed and got more and more yellow within hours.
All these compositions shown here were made with dual energy X-ray. The lowest energy of the tube is 40kV, which yields with 4 mAs a quite good insight of flowers. For the center of the Nautilus shell, 70kV and 2.5 mAs is more appropriate.
My first composition was a Nautilus taking off a bouquet of flowers. This reminded me of Renaissance engravings full of symbols. I do not feel depressed. The representation as a X-ray positive jsut shows the bouquet.
A more grounded composition is the second with a Nautilus shell moving towards the roots of my bouquet. Hopefully, the plants will survive. The positive representation always needs some extra editing. By just inverting the Blacks and the Whites the Nautilus would be too dark. Our reception cannot be just inverted and feels alright.
With the look-and-feel of old engravings in mind the third composition ist between surreal and a still. It took me some time to mask out the flaws of an original X-ray to get a true black background. Masking can be done iteratively and easily combined with Photoshop. („That’s what Photoshop is made for !“).
Some colorizing was done to overcome missing photographic shots. There was simply no time in my X-ray unit to do both at a time.
My fourth composition is called „The Argonauts“. The Nautilus shell serves as Argo, the legendary fast ship, with its crew, called Argonauts. The colored version is more convenient for our eyes. As before the X-ray positive looks more ethereal.
Today I put some tests on my cretean purchases from last September to evaluate their potential of being subject to fusion imaging. I bought three Nautilus shells and two sea snails, holding them in the store against the sun to check their transparency. My untidy studio accommodated these precious stones under quite a bunch of something.
The best representation is with a black background, i.e. with inverted L-channel in Lab colors. With a black background a soft shining light appears in the objects.
This snail has a shape a triangle and resembles a bear claw or an Apollo capsule in the late Sixties. The translucency is very little.
The following snail has a classic shape. With the black background it resembles a galaxy in outer space.
My first attempt with the Nautilus shells led me to a copper-like color representation with a single shot image. Lab colors is the key to this color and light distribution. Very attractive is the fact of two shells turning right and one left. Why did I wait so long to make this image ? Why do we miss important opportunities ?